There are a thousand or so web pages, videos and blogs about how to plumb.
All the self help tips you could ever want.
BUT.....
You really need to know your local codes and by-laws.
There are different laws and codes for different Countries, Regions, Provinces, Cities and the list goes on and on.
So, If you want to do your own repairs, great... all the power to you.
However on a personal note, It would be wiser to get a qualified trades person to do the work.
They would know your local laws and codes.
An example would be adding an ice maker to your fridge.
I saw a video on you tube where a guy was showing you how to install a saddle hub to get water for the fridge.
In the Province I live in, saddle hubs are against code. (However you can buy them at the local Home Depot)
Another thing you have to watch for is all these new plumbing items that are supposed to make plumbing installations easier for you.
You can buy them at Home Depot and other big box home renovation stores however if these items are not CSA approved, you shouldn't be using them.
I'm not picking on Home Depot, their just a store everyone can relate too.
I can go on and on here but I will just add some more posts as we go along here and address items as they come up.
Wednesday, July 16, 2008
Saturday, July 12, 2008
Following are some common energy-saving tactics. (Boilers)
Control excess combustion air. Controlling excess air is the most important tool for optimizing boiler efficiency. Too little air results in incomplete combustion, while too much air wastes energy, as the excess air is heated to the stack temperature.
Reducing the excess air nearly always yields a greater increase in efficiency. This results from a reduction in the flue gas temperature due to reduced mass flow and consequent improved heat transfer through the system. Stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency.
A number of controls are available for monitoring and optimizing the air-fuel mixture. These range from simple, low-cost on-off control to more expensive automatic oxygen trim control. Burner size determines which is the right control. The burner should be adjusted only by qualified personnel, so work with a supplier to correct the air-fuel mixture.
Train personnel. Have only well-trained, qualified personnel run, adjust, inspect and maintain boiler systems.
Keep the boiler clean. The fireside of the boiler tubes can accumulate deposits from burning fuel. This fouling can dramatically reduce heat transfer. Boilers that use solid fuels tend to foul much more than liquid- and gas-fuelled boilers. No. 6 (resid, heavy) oil has a greater fouling tendency than No. 2 oil. Natural gas boilers have a very low fouling tendency.
The waterside of the boiler tubes can become covered with a mineral deposit, or “scale”. Scale causes the tube's temperature to rise, raising the flue gas temperature and reducing the efficiency. Scale buildup can be tested with an automatic sensor while the boiler is running and can be treated chemically.
Boiler water should be tested daily in small low-pressure boilers and hourly in large high-pressure boilers. A gradual rise in flue gas temperature usually indicates that a deposit is accumulating on either the fireside or the waterside. If flue gas temperatures are too high, clean the system and adjust the water chemistry and the air-fuel mixture.
Large boilers often have soot blowers to clean fireside tube surfaces while the boiler is operating. Soot blowing can consume large amounts of energy, so it must be done carefully. Smaller boilers should be opened regularly for inspection and cleaning.
Minimize boiler short-cycling losses. When a boiler is too big, boiler short-cycling losses may occur. An oversized boiler will turn on and off more often than a boiler that has been properly matched to the demand. Every time the boiler turns on, extra energy is required to heat it back up to steady-state. A number of staged (or sequenced) smaller boilers use an automatic controller to lower costs by efficiently shifting the load between boilers. Piping and controlling the multiple boilers correctly is necessary for saving energy.
Minimize wasted blowdown water. Boiler water must be blown down periodically to prevent scale from forming on boiler tubes. This process can be wasteful if too much blowdown water is used. Automatic blowdown controls measure and respond to boiler water conductivity and acidity to ensure that only the right amount of blowdown water is used.
For further savings, a blowdown waste heat recovery system that preheats boiler feedwater can improve the system's efficiency by approximately 1 percent.
Use outdoor reset. Outdoor reset is used for hot-water building heating. In older systems, hot water arrives in the distribution system at the highest temperature the boiler provides. On-off controls regulate building temperature. Outdoor reset varies the temperature of the water in the distribution system in response to outdoor temperatures. When it is cold outside, the water temperature rises to match the heat loss from the building. When it is warm outside, there is less heat loss from the building, so the distributed water is cooler. Fuel consumption is reduced.
Conservative estimates put savings at 10 to 15 percent. This can also be an effective way of increasing latent heat recovery for high-efficiency condensing boilers.
Improve boiler insulation. A simple and cost-effective way of reducing heat loss through radiation and convection is by adding insulation directly to the outer walls of the boiler. Removable insulation pads will reduce losses and will not interfere with maintenance.
Reducing the excess air nearly always yields a greater increase in efficiency. This results from a reduction in the flue gas temperature due to reduced mass flow and consequent improved heat transfer through the system. Stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency.
A number of controls are available for monitoring and optimizing the air-fuel mixture. These range from simple, low-cost on-off control to more expensive automatic oxygen trim control. Burner size determines which is the right control. The burner should be adjusted only by qualified personnel, so work with a supplier to correct the air-fuel mixture.
Train personnel. Have only well-trained, qualified personnel run, adjust, inspect and maintain boiler systems.
Keep the boiler clean. The fireside of the boiler tubes can accumulate deposits from burning fuel. This fouling can dramatically reduce heat transfer. Boilers that use solid fuels tend to foul much more than liquid- and gas-fuelled boilers. No. 6 (resid, heavy) oil has a greater fouling tendency than No. 2 oil. Natural gas boilers have a very low fouling tendency.
The waterside of the boiler tubes can become covered with a mineral deposit, or “scale”. Scale causes the tube's temperature to rise, raising the flue gas temperature and reducing the efficiency. Scale buildup can be tested with an automatic sensor while the boiler is running and can be treated chemically.
Boiler water should be tested daily in small low-pressure boilers and hourly in large high-pressure boilers. A gradual rise in flue gas temperature usually indicates that a deposit is accumulating on either the fireside or the waterside. If flue gas temperatures are too high, clean the system and adjust the water chemistry and the air-fuel mixture.
Large boilers often have soot blowers to clean fireside tube surfaces while the boiler is operating. Soot blowing can consume large amounts of energy, so it must be done carefully. Smaller boilers should be opened regularly for inspection and cleaning.
Minimize boiler short-cycling losses. When a boiler is too big, boiler short-cycling losses may occur. An oversized boiler will turn on and off more often than a boiler that has been properly matched to the demand. Every time the boiler turns on, extra energy is required to heat it back up to steady-state. A number of staged (or sequenced) smaller boilers use an automatic controller to lower costs by efficiently shifting the load between boilers. Piping and controlling the multiple boilers correctly is necessary for saving energy.
Minimize wasted blowdown water. Boiler water must be blown down periodically to prevent scale from forming on boiler tubes. This process can be wasteful if too much blowdown water is used. Automatic blowdown controls measure and respond to boiler water conductivity and acidity to ensure that only the right amount of blowdown water is used.
For further savings, a blowdown waste heat recovery system that preheats boiler feedwater can improve the system's efficiency by approximately 1 percent.
Use outdoor reset. Outdoor reset is used for hot-water building heating. In older systems, hot water arrives in the distribution system at the highest temperature the boiler provides. On-off controls regulate building temperature. Outdoor reset varies the temperature of the water in the distribution system in response to outdoor temperatures. When it is cold outside, the water temperature rises to match the heat loss from the building. When it is warm outside, there is less heat loss from the building, so the distributed water is cooler. Fuel consumption is reduced.
Conservative estimates put savings at 10 to 15 percent. This can also be an effective way of increasing latent heat recovery for high-efficiency condensing boilers.
Improve boiler insulation. A simple and cost-effective way of reducing heat loss through radiation and convection is by adding insulation directly to the outer walls of the boiler. Removable insulation pads will reduce losses and will not interfere with maintenance.
Antimicrobial Copper Surfaces
Copper and its alloys, brass and bronze, are naturally antimicrobial materials. Recent
laboratory research performed under U.S. Environmental Protection Agency-approved
protocols demonstrated that copper alloy surfaces kill more than 99.9% of several
bacteria known to be human pathogens within two hours. Tests were conducted at room
temperature and under normal humidity conditions. The organisms tested were:
* Staphylococcus aureus
* Enterobacter aerogenes
* Escherichia coli O157:H7
* Pseudomonas aeruginosa and
* Methicillin-resistant Staphylococcus aureus (MRSA).
275 copper alloys, including brass and bronze, have been registered with the US EPA as
antimicrobial materials that kill these bacteria. The materials offer a wide range of
mechanical and aesthetic properties that make them ideal for use as antibacterial
surfaces. Copper alloys are the first solid materials ever to be granted such registration.
Typically, this type of registration has been granted to liquids (or aerosols) and gases
under the categories of sanitizers and disinfectants.
Frequently-touched surfaces in healthcare and other community facilities including public
and commercial buildings can become contaminated with bacteria. Using uncoated copper
alloys can be an effective way to kill the bacteria on these surfaces.
laboratory research performed under U.S. Environmental Protection Agency-approved
protocols demonstrated that copper alloy surfaces kill more than 99.9% of several
bacteria known to be human pathogens within two hours. Tests were conducted at room
temperature and under normal humidity conditions. The organisms tested were:
* Staphylococcus aureus
* Enterobacter aerogenes
* Escherichia coli O157:H7
* Pseudomonas aeruginosa and
* Methicillin-resistant Staphylococcus aureus (MRSA).
275 copper alloys, including brass and bronze, have been registered with the US EPA as
antimicrobial materials that kill these bacteria. The materials offer a wide range of
mechanical and aesthetic properties that make them ideal for use as antibacterial
surfaces. Copper alloys are the first solid materials ever to be granted such registration.
Typically, this type of registration has been granted to liquids (or aerosols) and gases
under the categories of sanitizers and disinfectants.
Frequently-touched surfaces in healthcare and other community facilities including public
and commercial buildings can become contaminated with bacteria. Using uncoated copper
alloys can be an effective way to kill the bacteria on these surfaces.
Some Copper History
- One of the famous Dead Sea Scrolls found in Israel is made of
copper instead of fragile animal skins. The scroll
contains clues to a still undiscovered treasure.
- Archeologists have recovered a portion of a water plumbing
system from the Pyramid of Cheops in Egypt. After
5,000 years, the copper tubing was still in serviceable condition.
- A copper frying pan at the University of Pennsylvania's
museum has been dated to be more than 50 centuries old.
- When Columbus sailed to America, his ships (Nina, Pinta, and
Santa Maria) had copper skins below the water line.
The copper sheathing extended hull life and protected against
barnacles and other types of biofouling. Today, most
sea-going vessels use a copper-based paint for hull protection.
Archaeological evidence indicates that copper was used as far
back as 10,000 years ago in western Asia. During the
prehistoric Chalcolithic Period, societies discovered how to
extract and use copper to produce ornaments and
implements. As early as the 3rd-4th Millennium BC, copper was
actively extracted from Spain's Huelva region.
Around 2500 BC, the discovery of useful properties of copper-
tin alloys led to the Bronze Age.
It has been documented that Israel's Timna Valley provided
copper for the Pharaohs. Papyrus records from ancient
Egypt reveal that copper was used to treat infections and
sterilize water. The island of Cyprus is known to have
supplied much of the copper needed for the empires of ancient
Phoenicia, Greece, and Rome.
While the Greeks during Aristotle's era were familiar with brass,
it was not until Augustus' Imperial Rome that brass
became abundantly used. In South America, the pre-Columbian
Maya, Aztec, and Inca civilizations exploited
copper, as well as gold and silver. During the Middle Ages,
copper and bronze flourished in China, India, and Japan.
The discoveries and inventions in the late 18th and early 19th
Centuries by Ampere, Faraday, and Ohm propelled
copper into a new era. Demonstrating excellent electrical
conducting and heat transfer characteristics, copper played
a pivotal role in launching the Industrial Revolution.
Copper Alloys
- Over 400 copper alloys are in use today.
- Brass is an alloy of copper and zinc.
- Bronze is an alloy of copper and tin, aluminum, silicon, and beryllium.
- Copper-nickel and copper-silver alloys are important metals in today's world.
The industrial importance of copper in the 20th Century has been extended by the ease with which it combines with other metals. Tin and zinc have always been the principal alloying elements, but there are now many others - aluminum, beryllium, chromium, manganese, etc. - which form alloys with special mechanical and physical properties.
Alloys containing copper fall into main types: Copper-base alloys, such as brass, tin bronze and aluminum bronze, in which copper itself is the predominant element; and Copper-bearing alloys, such as certain aluminum alloys, high-duty alloys to resist severe corrosion, and steels and cast irons which are improved by small additions of copper. The proprietary alloy 'Monel', a mixture of copper and larger amounts of nickel, occupies an intermediate field between these two main classes.
Maintenance and Repairs (Hydronic Heat)
It is recommended that annual maintenance be done on mechanical equipment such as the pumps, hot water heater, controls etc. If there was a problem or failure, it is commonly found in these mechanical parts. It is recommended that the installer be contacted for annual maintenance.
For repairs to the system, the homeowner should contact the installer. Be sure to have your design plan available for tubing location.
To avoid unnecessary repair work, all equipment must be used and maintained in the manner in which it was designed and installed. Homeowners disconnecting controls or moving pumps can find themselves requiring repairs and possibly voiding their warranty.
Lifespan
While the heat source in a properly maintained system can last for as long as 30 to 40 years, PEX pipes set in the floor are expected to last more than 50 years. (Some test results indicate life expectancies of 200-300 years.)
Warranty
There are two types of warranties: a Manufacturer’s Warranty and an Installation
Warranty.
Most manufactures’ warranty policies are strongly dependant on certified and qualified mechanical contractors completing the installation. All require Code regulations be followed for the jurisdiction in which the home is being built. Some manufacturers also require that specific devices be field installed by the mechanical contractor to ensure full warranty coverage. There is no difference in warranty between new construction and renovations and the warranty should be given to the consumer in writing.
Installation warranty varies on the heating contractor and their warranty policies. There may be a difference in warranty between new home construction and renovations by the heating contractor.
Benefits
Comfort
Radiant floor heating provides even, comfortable, warmth as there is less air movement with this type of system. There are no drafts with this type of heating, unless it is through the building envelope. The thermal mass (concrete floor) evens out the temperature fluctuations. The floor is warm to the touch.
Energy-Efficiency
Many manufacturers claim that radiant floor heating is more economical to operate because the temperature setting may be set to 20ºC (68ºF) rather than the usual 21-22ºC (70-72ºF) as required by other types of systems. A study by CMHC (Thermostat Settings in Houses with In-Floor Heating, #01-106) has shown that people tend to keep their thermostats set the same as if they had a forced air system. Even so, the warmest air is at the floor where it is desired (and not at the ceiling) and there is reduced heat loss through the ceiling and walls.
Zoning a variety of rooms with the options for different temperatures has the potential to reduce energy consumption.
Energy Source Compatibility
Since radiant floor heating has a low operating temperature, a wide range of sources can be used to heat the water–a ground-source heat pump, a condensing or non-condensing boiler, solar or even district heating.
Quietness
The system is quiet because a properly-sized circulator pump, used to slowly move the water, is almost inaudible. The loudest sound in the system is usually the gas or oil burner.
Cleanliness
Unlike conventional forced-air furnaces, radiant floor heating has no ducts or radiators to contribute to dust collection or movement. Note: duct work is required for the mechanical ventilation system or air conditioning.
For residents with allergies, the reduction in dust movement may be beneficial.
Room Function
Hydronic radiant floor heating is virtually an invisible system. Without baseboard heaters, forced air registers etc, furniture layout is not restricted by the heating system. Bathrooms or special use areas with hard floor finishes are well suited to this type of heating.
Cautions and Solutions
Due to thermal mass, the system may be slower to respond to temperature changes. Overheating can occur in poorly controlled or zoned systems. The system is not designed to have the temperature frequently adjusted.
Night setbacks are not practical in most situations as the system is slow to react.
Ventilation must be done separately. As air conditioning cannot be used in ventilation-sized ducts, window/wall air conditioning can be installed or room-by-room split systems can be used. Additionally, high-velocity air conditioning systems that use small outlets in ceiling or walls have proven very compatible with radiant floor heating operation.
Extra support may be needed for the weight of thermal mass topping on a wood floor. If the building structure can’t support the weight, then the dry plate system can be considered.
This is not a do-it-yourself project. It requires professional installation, maintenance and repair. Having professionals do the installation will allow you to have the best performance and warranty on the heating system.
More Information
Heating contractors, heating equipment wholesalers and heating associations (for example, Canadian Hydronics Council and the Hydronic Marketing Group) can provide specific information on hydronic radiant heat products. The Yellow PagesTM or Internet, provides a variety of sources.
For repairs to the system, the homeowner should contact the installer. Be sure to have your design plan available for tubing location.
To avoid unnecessary repair work, all equipment must be used and maintained in the manner in which it was designed and installed. Homeowners disconnecting controls or moving pumps can find themselves requiring repairs and possibly voiding their warranty.
Lifespan
While the heat source in a properly maintained system can last for as long as 30 to 40 years, PEX pipes set in the floor are expected to last more than 50 years. (Some test results indicate life expectancies of 200-300 years.)
Warranty
There are two types of warranties: a Manufacturer’s Warranty and an Installation
Warranty.
Most manufactures’ warranty policies are strongly dependant on certified and qualified mechanical contractors completing the installation. All require Code regulations be followed for the jurisdiction in which the home is being built. Some manufacturers also require that specific devices be field installed by the mechanical contractor to ensure full warranty coverage. There is no difference in warranty between new construction and renovations and the warranty should be given to the consumer in writing.
Installation warranty varies on the heating contractor and their warranty policies. There may be a difference in warranty between new home construction and renovations by the heating contractor.
Benefits
Comfort
Radiant floor heating provides even, comfortable, warmth as there is less air movement with this type of system. There are no drafts with this type of heating, unless it is through the building envelope. The thermal mass (concrete floor) evens out the temperature fluctuations. The floor is warm to the touch.
Energy-Efficiency
Many manufacturers claim that radiant floor heating is more economical to operate because the temperature setting may be set to 20ºC (68ºF) rather than the usual 21-22ºC (70-72ºF) as required by other types of systems. A study by CMHC (Thermostat Settings in Houses with In-Floor Heating, #01-106) has shown that people tend to keep their thermostats set the same as if they had a forced air system. Even so, the warmest air is at the floor where it is desired (and not at the ceiling) and there is reduced heat loss through the ceiling and walls.
Zoning a variety of rooms with the options for different temperatures has the potential to reduce energy consumption.
Energy Source Compatibility
Since radiant floor heating has a low operating temperature, a wide range of sources can be used to heat the water–a ground-source heat pump, a condensing or non-condensing boiler, solar or even district heating.
Quietness
The system is quiet because a properly-sized circulator pump, used to slowly move the water, is almost inaudible. The loudest sound in the system is usually the gas or oil burner.
Cleanliness
Unlike conventional forced-air furnaces, radiant floor heating has no ducts or radiators to contribute to dust collection or movement. Note: duct work is required for the mechanical ventilation system or air conditioning.
For residents with allergies, the reduction in dust movement may be beneficial.
Room Function
Hydronic radiant floor heating is virtually an invisible system. Without baseboard heaters, forced air registers etc, furniture layout is not restricted by the heating system. Bathrooms or special use areas with hard floor finishes are well suited to this type of heating.
Cautions and Solutions
Due to thermal mass, the system may be slower to respond to temperature changes. Overheating can occur in poorly controlled or zoned systems. The system is not designed to have the temperature frequently adjusted.
Night setbacks are not practical in most situations as the system is slow to react.
Ventilation must be done separately. As air conditioning cannot be used in ventilation-sized ducts, window/wall air conditioning can be installed or room-by-room split systems can be used. Additionally, high-velocity air conditioning systems that use small outlets in ceiling or walls have proven very compatible with radiant floor heating operation.
Extra support may be needed for the weight of thermal mass topping on a wood floor. If the building structure can’t support the weight, then the dry plate system can be considered.
This is not a do-it-yourself project. It requires professional installation, maintenance and repair. Having professionals do the installation will allow you to have the best performance and warranty on the heating system.
More Information
Heating contractors, heating equipment wholesalers and heating associations (for example, Canadian Hydronics Council and the Hydronic Marketing Group) can provide specific information on hydronic radiant heat products. The Yellow PagesTM or Internet, provides a variety of sources.
Installation
There are three choices of installation:
1. Slab-on-grade system: One example of a slab-on-grade system is PEX tubing attached to a wire mesh or clipped onto rigid Styrofoam insulation. Concrete is poured over the piping or tubing at the ground “grade” level. The slab must be insulated from the exterior side of the floor all the way to the slab edges.
2. Thin slab system:
1. The floor heating tubing is fastened above the subfloor and is covered with lightweight concrete or selflevelling gypsum cement underlayment. The floor ranges in thickness from 3.2 to 3.8 cm (1.25 to 1.5 in).
2. Another version is to sandwich the tubing between the subfloor and the finished floor. This raises the floor only 1.3 cm (1/2 in). There are a variety of new underlayment panels that hold the tubing in place and incorporate aluminum transfer plates to improve heating performance.
3. Dry or “Plate” system: Tubing is attached to the underside of the subfloor, also known as a belowdeck or joist space dry system. In cold weather climates, tubing should be attached with aluminum transfer plates and both well insulated for improved performance. Without the insulation, the warmth will disperse into the basement. It is also possible to have an abovedeck dry system, where heat transfer plates are supported by sleepers.
It is recommended that a licensed contractor install the heating system.
Costs
An approximate cost of an installed hydronic radiant floor heating system by a licensed mechanical contractor can range from $600 to $800 per approximately 100 square feet. This cost can be more or less depending on specific heating requirements and energy efficiency results. In addition to the heating system, a mechanical ventilation system is required in the house.
1. Slab-on-grade system: One example of a slab-on-grade system is PEX tubing attached to a wire mesh or clipped onto rigid Styrofoam insulation. Concrete is poured over the piping or tubing at the ground “grade” level. The slab must be insulated from the exterior side of the floor all the way to the slab edges.
2. Thin slab system:
1. The floor heating tubing is fastened above the subfloor and is covered with lightweight concrete or selflevelling gypsum cement underlayment. The floor ranges in thickness from 3.2 to 3.8 cm (1.25 to 1.5 in).
2. Another version is to sandwich the tubing between the subfloor and the finished floor. This raises the floor only 1.3 cm (1/2 in). There are a variety of new underlayment panels that hold the tubing in place and incorporate aluminum transfer plates to improve heating performance.
3. Dry or “Plate” system: Tubing is attached to the underside of the subfloor, also known as a belowdeck or joist space dry system. In cold weather climates, tubing should be attached with aluminum transfer plates and both well insulated for improved performance. Without the insulation, the warmth will disperse into the basement. It is also possible to have an abovedeck dry system, where heat transfer plates are supported by sleepers.
It is recommended that a licensed contractor install the heating system.
Costs
An approximate cost of an installed hydronic radiant floor heating system by a licensed mechanical contractor can range from $600 to $800 per approximately 100 square feet. This cost can be more or less depending on specific heating requirements and energy efficiency results. In addition to the heating system, a mechanical ventilation system is required in the house.
Design
Prior to the installation of a system, a qualified floor-heating specialist should make a heating-load estimate of your home on a room-by-room basis. The heating-load estimate will assist in an efficient system design. By placing the tubing in specific patterns and spacings, the system can accommodate the insulation of the room/home and flooring choices.
Once designed and installed, a copy of the design should be given to the homeowner, should pipes/tubing need to be located at a later date. When renovating, extra care must be taken that piping or tubing not be punctured.
Exposed surfaces that conduct heat well are best for radiant floor heating, such as finished concrete or ceramic tile. It should be noted that if any later flooring renovation is undertaken, the hydronic radiant floor heating installer should be notified to make any required adjustments to the heating system. For example, the water temperature of the heating system would need to be adjusted if there was a change from a bare or painted finished floor slab to ceramic tile, or wood flooring or to carpet with underlay. Wood flooring and thick carpets act as an insulation blanket, restricting upward heat flow and reduce the efficiency of the system.
System Components
There are three components to this heating system: a heat source, a distribution piping system and controls. The heat source in hydronic radiant floor heating is usually a boiler or a hot water heater, but other heat sources can be used too. The energy used to heat the hot water can be natural gas, oil, electricity, propane, wood or solar hot water collection.
A circulator pump near the water supply manifold moves the water from the mixing valve to the supply manifold into the distribution piping system (tubing) inside the floors. Properly designed, this delivers even heat to rooms. A properly designed radiant floor system will not exceed 29ºC (85ºF).
To select how warm or cool a room or home will be, controls are required to set the system to a particular temperature. A manifold system with thermostat or aquastat switches typically located in an accessible wall cavity provides a series of simple valves that are used to regulate the flow of water through each zone. There is a caution not to exceed the recommended maximum temperature as it could warp solid hardwood flooring and cause stress to the system.
Once designed and installed, a copy of the design should be given to the homeowner, should pipes/tubing need to be located at a later date. When renovating, extra care must be taken that piping or tubing not be punctured.
Exposed surfaces that conduct heat well are best for radiant floor heating, such as finished concrete or ceramic tile. It should be noted that if any later flooring renovation is undertaken, the hydronic radiant floor heating installer should be notified to make any required adjustments to the heating system. For example, the water temperature of the heating system would need to be adjusted if there was a change from a bare or painted finished floor slab to ceramic tile, or wood flooring or to carpet with underlay. Wood flooring and thick carpets act as an insulation blanket, restricting upward heat flow and reduce the efficiency of the system.
System Components
There are three components to this heating system: a heat source, a distribution piping system and controls. The heat source in hydronic radiant floor heating is usually a boiler or a hot water heater, but other heat sources can be used too. The energy used to heat the hot water can be natural gas, oil, electricity, propane, wood or solar hot water collection.
A circulator pump near the water supply manifold moves the water from the mixing valve to the supply manifold into the distribution piping system (tubing) inside the floors. Properly designed, this delivers even heat to rooms. A properly designed radiant floor system will not exceed 29ºC (85ºF).
To select how warm or cool a room or home will be, controls are required to set the system to a particular temperature. A manifold system with thermostat or aquastat switches typically located in an accessible wall cavity provides a series of simple valves that are used to regulate the flow of water through each zone. There is a caution not to exceed the recommended maximum temperature as it could warp solid hardwood flooring and cause stress to the system.
Is this type of heating available in both new and existing homes?
Yes. While the system can be easily designed and installed in new construction, homeowners wishing to renovate may incorporate hydronic radiant floor heating throughout the home, given certain conditions exist:
* the building structure can support the additional weight of the concrete/cement overpour, or
* the underside of the subfloor is accessible, or
* if being added to the basement, there is enough height for a concrete overpour above the insulation. (If the concrete floor is already insulated below, additional insulation is not necessary.)
Entire House Versus Selected Rooms
Homeowners can chose to install hydronic radiant floor heating throughout the house, or in selected rooms (see Figure 3). The most popular rooms with this type of heating are the bathroom, kitchen and living room–rooms where the most time is spent. If only selected rooms have this type of heating, then a separate heating and ventilation system is required to heat the remainder of the home. The system can also be “zoned” so that there are temperature controls for each area.
* the building structure can support the additional weight of the concrete/cement overpour, or
* the underside of the subfloor is accessible, or
* if being added to the basement, there is enough height for a concrete overpour above the insulation. (If the concrete floor is already insulated below, additional insulation is not necessary.)
Entire House Versus Selected Rooms
Homeowners can chose to install hydronic radiant floor heating throughout the house, or in selected rooms (see Figure 3). The most popular rooms with this type of heating are the bathroom, kitchen and living room–rooms where the most time is spent. If only selected rooms have this type of heating, then a separate heating and ventilation system is required to heat the remainder of the home. The system can also be “zoned” so that there are temperature controls for each area.
Hydronic Radiant Floor Heating
Long ago, the Romans used radiant floor heating in their bathhouses. For centuries, the Koreans heated their royal palaces and traditional homes in this manner. Today, radiant heating technology has been improved and can be used in all or part of our homes.
What is radiant floor heating?
Radiant floor heating is a method of heating your home by applying heat underneath or within the floor. Comparable to warming yourself in the sun, this type of heating warms objects as opposed to raising the temperature of the air.
There are three types of radiant floor heating: hydronic, electric and air. This About Your House document focuses on hydronic (water) radiant floor heating.
Brought to North America post World War II, the first generation of North American systems met with several mechanical failures. The introduction of carpeted floors reduced the system efficiency. Today, significant improvements have been made in both the heating component and the system design.
Hydronic radiant floor heating is a system of plastic or metal tubes/pipes laid within a floor that carries hot water into specific rooms or “zones”, dispersing the heat through the floor surface (see Figure 1).
The cooler water returns to the heat source where it is reheated and sent out again in what is known as a “closed-loop system”. The pipes can be encased in a concrete slab, a concrete or gypsum cement overpour, laid into thin grooved panels that nail on top of a subfloor, or suspended below a wooden subfloor using metal fins fastened under the floor surface (see Figure 2). The heat output is determined by pipe spacing, water temperature, flow rate and floor covering. The heat output must be calculated to meet the heat loss demands of the home.
One type of tubing commonly used is a new leak-resistant, non-toxic, high temperature, flexible piping called cross-linked polyethylene (PEX). PEX is a durable tubing that doesn’t become brittle over time and isn’t affected by aggressive concrete additives or water conditions. PEX has been used in Europe since the 1970s and was introduced to North America in the early 1980s.
What is radiant floor heating?
Radiant floor heating is a method of heating your home by applying heat underneath or within the floor. Comparable to warming yourself in the sun, this type of heating warms objects as opposed to raising the temperature of the air.
There are three types of radiant floor heating: hydronic, electric and air. This About Your House document focuses on hydronic (water) radiant floor heating.
Brought to North America post World War II, the first generation of North American systems met with several mechanical failures. The introduction of carpeted floors reduced the system efficiency. Today, significant improvements have been made in both the heating component and the system design.
Hydronic radiant floor heating is a system of plastic or metal tubes/pipes laid within a floor that carries hot water into specific rooms or “zones”, dispersing the heat through the floor surface (see Figure 1).
The cooler water returns to the heat source where it is reheated and sent out again in what is known as a “closed-loop system”. The pipes can be encased in a concrete slab, a concrete or gypsum cement overpour, laid into thin grooved panels that nail on top of a subfloor, or suspended below a wooden subfloor using metal fins fastened under the floor surface (see Figure 2). The heat output is determined by pipe spacing, water temperature, flow rate and floor covering. The heat output must be calculated to meet the heat loss demands of the home.
One type of tubing commonly used is a new leak-resistant, non-toxic, high temperature, flexible piping called cross-linked polyethylene (PEX). PEX is a durable tubing that doesn’t become brittle over time and isn’t affected by aggressive concrete additives or water conditions. PEX has been used in Europe since the 1970s and was introduced to North America in the early 1980s.
Operation and Maintenance Tips
A systems approach is the best way to save energy. This means looking at the boiler, the steam distribution system and the end uses together.
Following are some common energy-saving tactics.
Control excess combustion air. Controlling excess air is the most important tool for optimizing boiler efficiency. Too little air results in incomplete combustion, while too much air wastes energy, as the excess air is heated to the stack temperature.
Reducing the excess air nearly always yields a greater increase in efficiency. This results from a reduction in the flue gas temperature due to reduced mass flow and consequent improved heat transfer through the system. Stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency.
A number of controls are available for monitoring and optimizing the air-fuel mixture. These range from simple, low-cost on-off control to more expensive automatic oxygen trim control. Burner size determines which is the right control. The burner should be adjusted only by qualified personnel, so work with a supplier to correct the air-fuel mixture.
Train personnel. Have only well-trained, qualified personnel run, adjust, inspect and maintain boiler systems.
Keep the boiler clean. The fireside of the boiler tubes can accumulate deposits from burning fuel. This fouling can dramatically reduce heat transfer. Boilers that use solid fuels tend to foul much more than liquid- and gas-fuelled boilers. No. 6 (resid, heavy) oil has a greater fouling tendency than No. 2 oil. Natural gas boilers have a very low fouling tendency.
The waterside of the boiler tubes can become covered with a mineral deposit, or “scale”. Scale causes the tube's temperature to rise, raising the flue gas temperature and reducing the efficiency. Scale buildup can be tested with an automatic sensor while the boiler is running and can be treated chemically.
Boiler water should be tested daily in small low-pressure boilers and hourly in large high-pressure boilers. A gradual rise in flue gas temperature usually indicates that a deposit is accumulating on either the fireside or the waterside. If flue gas temperatures are too high, clean the system and adjust the water chemistry and the air-fuel mixture.
Large boilers often have soot blowers to clean fireside tube surfaces while the boiler is operating. Soot blowing can consume large amounts of energy, so it must be done carefully. Smaller boilers should be opened regularly for inspection and cleaning.
Minimize boiler short-cycling losses. When a boiler is too big, boiler short-cycling losses may occur. An oversized boiler will turn on and off more often than a boiler that has been properly matched to the demand. Every time the boiler turns on, extra energy is required to heat it back up to steady-state. A number of staged (or sequenced) smaller boilers use an automatic controller to lower costs by efficiently shifting the load between boilers. Piping and controlling the multiple boilers correctly is necessary for saving energy.
Minimize wasted blowdown water. Boiler water must be blown down periodically to prevent scale from forming on boiler tubes. This process can be wasteful if too much blowdown water is used. Automatic blowdown controls measure and respond to boiler water conductivity and acidity to ensure that only the right amount of blowdown water is used.
For further savings, a blowdown waste heat recovery system that preheats boiler feedwater can improve the system's efficiency by approximately 1 percent.
Use outdoor reset. Outdoor reset is used for hot-water building heating. In older systems, hot water arrives in the distribution system at the highest temperature the boiler provides. On-off controls regulate building temperature. Outdoor reset varies the temperature of the water in the distribution system in response to outdoor temperatures. When it is cold outside, the water temperature rises to match the heat loss from the building. When it is warm outside, there is less heat loss from the building, so the distributed water is cooler. Fuel consumption is reduced.
Conservative estimates put savings at 10 to 15 percent. This can also be an effective way of increasing latent heat recovery for high-efficiency condensing boilers.
Improve boiler insulation. A simple and cost-effective way of reducing heat loss through radiation and convection is by adding insulation directly to the outer walls of the boiler. Removable insulation pads will reduce losses and will not interfere with maintenance.
Following are some common energy-saving tactics.
Control excess combustion air. Controlling excess air is the most important tool for optimizing boiler efficiency. Too little air results in incomplete combustion, while too much air wastes energy, as the excess air is heated to the stack temperature.
Reducing the excess air nearly always yields a greater increase in efficiency. This results from a reduction in the flue gas temperature due to reduced mass flow and consequent improved heat transfer through the system. Stack temperature and flue gas oxygen (or carbon dioxide) concentrations are primary indicators of combustion efficiency.
A number of controls are available for monitoring and optimizing the air-fuel mixture. These range from simple, low-cost on-off control to more expensive automatic oxygen trim control. Burner size determines which is the right control. The burner should be adjusted only by qualified personnel, so work with a supplier to correct the air-fuel mixture.
Train personnel. Have only well-trained, qualified personnel run, adjust, inspect and maintain boiler systems.
Keep the boiler clean. The fireside of the boiler tubes can accumulate deposits from burning fuel. This fouling can dramatically reduce heat transfer. Boilers that use solid fuels tend to foul much more than liquid- and gas-fuelled boilers. No. 6 (resid, heavy) oil has a greater fouling tendency than No. 2 oil. Natural gas boilers have a very low fouling tendency.
The waterside of the boiler tubes can become covered with a mineral deposit, or “scale”. Scale causes the tube's temperature to rise, raising the flue gas temperature and reducing the efficiency. Scale buildup can be tested with an automatic sensor while the boiler is running and can be treated chemically.
Boiler water should be tested daily in small low-pressure boilers and hourly in large high-pressure boilers. A gradual rise in flue gas temperature usually indicates that a deposit is accumulating on either the fireside or the waterside. If flue gas temperatures are too high, clean the system and adjust the water chemistry and the air-fuel mixture.
Large boilers often have soot blowers to clean fireside tube surfaces while the boiler is operating. Soot blowing can consume large amounts of energy, so it must be done carefully. Smaller boilers should be opened regularly for inspection and cleaning.
Minimize boiler short-cycling losses. When a boiler is too big, boiler short-cycling losses may occur. An oversized boiler will turn on and off more often than a boiler that has been properly matched to the demand. Every time the boiler turns on, extra energy is required to heat it back up to steady-state. A number of staged (or sequenced) smaller boilers use an automatic controller to lower costs by efficiently shifting the load between boilers. Piping and controlling the multiple boilers correctly is necessary for saving energy.
Minimize wasted blowdown water. Boiler water must be blown down periodically to prevent scale from forming on boiler tubes. This process can be wasteful if too much blowdown water is used. Automatic blowdown controls measure and respond to boiler water conductivity and acidity to ensure that only the right amount of blowdown water is used.
For further savings, a blowdown waste heat recovery system that preheats boiler feedwater can improve the system's efficiency by approximately 1 percent.
Use outdoor reset. Outdoor reset is used for hot-water building heating. In older systems, hot water arrives in the distribution system at the highest temperature the boiler provides. On-off controls regulate building temperature. Outdoor reset varies the temperature of the water in the distribution system in response to outdoor temperatures. When it is cold outside, the water temperature rises to match the heat loss from the building. When it is warm outside, there is less heat loss from the building, so the distributed water is cooler. Fuel consumption is reduced.
Conservative estimates put savings at 10 to 15 percent. This can also be an effective way of increasing latent heat recovery for high-efficiency condensing boilers.
Improve boiler insulation. A simple and cost-effective way of reducing heat loss through radiation and convection is by adding insulation directly to the outer walls of the boiler. Removable insulation pads will reduce losses and will not interfere with maintenance.
Condensing Boilers
High-efficiency condensing boilers feature additional advanced heat exchanger designs and materials that extract more heat from the flue gases before they are exhausted. The temperature of the flue gases is reduced to the point where the water vapour produced during combustion condenses back into liquid form, releasing the latent heat, which improves energy efficiency. With some 12 percent of the energy of a gas-fired boiler tied up as latent heat, this represents a significant energy-savings potential. A side effect is that this condensate is usually acidic and has to be piped to a drain.
Modern condensing boilers have energy efficiencies of 90 to 96 percent. New conventional non-condensing models have energy efficiencies of only 70 to 85 percent. Many boilers over 20 years old typically operate at only 60 to 70 percent efficiency, making them good candidates for upgrading or replacement. A number of natural-gas-fired condensing boilers are available, but very few oil-burning ones are on the market.
An important point is that for the water vapour in the flue gases to condense, the temperature of the flue gas must be reduced to below the water dew point of the flue gas. For this to occur, the return water temperature to the boiler proper must be below 60°C. If there are no heat exchange surfaces at the back of the boiler below this dewpoint, condensing will not occur, and this energy opportunity will be lost, even if the boiler is a “condensing” boiler.
In retrofit applications where you wish to retain your existing boiler, boiler efficiency can be improved by adding an economizer, which is a heat exchanger that utilizes the waste heat from the flue gas to preheat the boiler feedwater. A condensing economizer improves the effectiveness of reclaiming flue gas heat by cooling the flue gas below the dewpoint. The condensing economizer thus recovers both the sensible heat from the flue gas and the latent heat from the moisture that condenses. You do have to ensure, however, that the condensate does not enter the boiler, as the condensate is highly corrosive.
Oil condensing boilers are more expensive, and it is much harder for them to actually achieve condensing because:
* Sulphur in the oil turns the condensed water into sulphuric acid that must be neutralized. The heat exchanger must be of very high quality to prevent corrosion by the acid.
* Oil has 50 percent less energy tied up in latent heat, compared with natural gas.
* The dew point for oil is low – 47°C compared with 60°C – for natural gas, making the water vapour in the flue gas very difficult to condense.
Modern condensing boilers have energy efficiencies of 90 to 96 percent. New conventional non-condensing models have energy efficiencies of only 70 to 85 percent. Many boilers over 20 years old typically operate at only 60 to 70 percent efficiency, making them good candidates for upgrading or replacement. A number of natural-gas-fired condensing boilers are available, but very few oil-burning ones are on the market.
An important point is that for the water vapour in the flue gases to condense, the temperature of the flue gas must be reduced to below the water dew point of the flue gas. For this to occur, the return water temperature to the boiler proper must be below 60°C. If there are no heat exchange surfaces at the back of the boiler below this dewpoint, condensing will not occur, and this energy opportunity will be lost, even if the boiler is a “condensing” boiler.
In retrofit applications where you wish to retain your existing boiler, boiler efficiency can be improved by adding an economizer, which is a heat exchanger that utilizes the waste heat from the flue gas to preheat the boiler feedwater. A condensing economizer improves the effectiveness of reclaiming flue gas heat by cooling the flue gas below the dewpoint. The condensing economizer thus recovers both the sensible heat from the flue gas and the latent heat from the moisture that condenses. You do have to ensure, however, that the condensate does not enter the boiler, as the condensate is highly corrosive.
Oil condensing boilers are more expensive, and it is much harder for them to actually achieve condensing because:
* Sulphur in the oil turns the condensed water into sulphuric acid that must be neutralized. The heat exchanger must be of very high quality to prevent corrosion by the acid.
* Oil has 50 percent less energy tied up in latent heat, compared with natural gas.
* The dew point for oil is low – 47°C compared with 60°C – for natural gas, making the water vapour in the flue gas very difficult to condense.
Improved Combustion System Efficiency
New boilers generally incorporate several new technologies. These same technologies can also be applied when retrofitting older boilers. The most important new technologies are as follows.
* Fan-assisted combustion: Originally, boilers and furnaces relied on natural draft, i.e., the buoyancy of the hot air in the flue, to draw the air into the firebox and up the flue. A draft hood limited condensation in the flue and ensured that the burner and flame were isolated from outside air pressure fluctuations by adding "dilution" air to the flue. At the same time, the dilution air lowered the vapour pressure at which the flue gases would condense and cause damage to the flue. However, efficiency was lost because of the loss of heated interior air up the chimney.
Newer-technology fan-assisted burners eliminate the draft hood and are better at mixing fuel and air. As a result, excess air is reduced. Fan-assisted burners also diminish losses by reducing the amount of hot air going up the chimney.
The fan also improves the heat transfer inside the boiler by improving combustion gas flow through the heat exchanger.
Two types of fan-assisted systems are available: a forced-draft system uses a fan to blow the fuel and air mixture into the boiler; an induced-draft system has the fan located at the outlet end of the heat exchanger passages.
* Motorized dampers: Motorized dampers stop heat from escaping up the chimney by automatically closing the flue when the boiler is idle.
* Electric ignition: Older gas boilers have pilot flames that remain lit whether the boiler is firing or idle. Electric ignitions or other intermittent ignition devices eliminate this waste of fuel. A control circuit energizes the ignitor and, if the burner does not fire on the first try, the ignitor re-fires until the burner is lit.
* Sealed combustion: Sealed combustion controls the combustion process more carefully by preventing boilers from inducing infiltration into the building. In a sealed combustion boiler, air is drawn directly from outside through a sealed venting system, ensuring that heated indoor air is not mixed with the outside air during the combustion process.
* Pulse combustion: Instead of a continuous flame, pulse systems create discrete, rapid combustion pulses in a sealed chamber. This intensely turbulent process results in a highly efficient heat transfer to the heat exchanger and allows for flue gas condensation in condensing boilers.
* Fan-assisted combustion: Originally, boilers and furnaces relied on natural draft, i.e., the buoyancy of the hot air in the flue, to draw the air into the firebox and up the flue. A draft hood limited condensation in the flue and ensured that the burner and flame were isolated from outside air pressure fluctuations by adding "dilution" air to the flue. At the same time, the dilution air lowered the vapour pressure at which the flue gases would condense and cause damage to the flue. However, efficiency was lost because of the loss of heated interior air up the chimney.
Newer-technology fan-assisted burners eliminate the draft hood and are better at mixing fuel and air. As a result, excess air is reduced. Fan-assisted burners also diminish losses by reducing the amount of hot air going up the chimney.
The fan also improves the heat transfer inside the boiler by improving combustion gas flow through the heat exchanger.
Two types of fan-assisted systems are available: a forced-draft system uses a fan to blow the fuel and air mixture into the boiler; an induced-draft system has the fan located at the outlet end of the heat exchanger passages.
* Motorized dampers: Motorized dampers stop heat from escaping up the chimney by automatically closing the flue when the boiler is idle.
* Electric ignition: Older gas boilers have pilot flames that remain lit whether the boiler is firing or idle. Electric ignitions or other intermittent ignition devices eliminate this waste of fuel. A control circuit energizes the ignitor and, if the burner does not fire on the first try, the ignitor re-fires until the burner is lit.
* Sealed combustion: Sealed combustion controls the combustion process more carefully by preventing boilers from inducing infiltration into the building. In a sealed combustion boiler, air is drawn directly from outside through a sealed venting system, ensuring that heated indoor air is not mixed with the outside air during the combustion process.
* Pulse combustion: Instead of a continuous flame, pulse systems create discrete, rapid combustion pulses in a sealed chamber. This intensely turbulent process results in a highly efficient heat transfer to the heat exchanger and allows for flue gas condensation in condensing boilers.
How Can the Combustion System Be Improved?
Flue gases are the single most important cause of energy loss. As much as 18 to 22 percent of available energy goes up the chimney. Heat radiation and convection from boiler walls raise heat loss another 1 to 4 percent.
There are four main ways of reducing flue gas energy losses:
* by improving the efficiency of converting the fuel to heat (improved combustion system efficiency)
* by requiring less air for satisfactory combustion
* by ensuring that the boiler casing is tight, so that there is no air/heat entering or leaving the casing through leaks
* by improving the efficiency of transferring the heat to the steam or hot water (improved heat exchanger efficiency)
Operating practices such as blowdown cause other losses, as do inefficiencies in steam and hot water distribution systems.
There are four main ways of reducing flue gas energy losses:
* by improving the efficiency of converting the fuel to heat (improved combustion system efficiency)
* by requiring less air for satisfactory combustion
* by ensuring that the boiler casing is tight, so that there is no air/heat entering or leaving the casing through leaks
* by improving the efficiency of transferring the heat to the steam or hot water (improved heat exchanger efficiency)
Operating practices such as blowdown cause other losses, as do inefficiencies in steam and hot water distribution systems.
Measuring Boiler Efficiency
Boilers with heat outputs of 300 000 Btu/hr to 2 500 000 Btu/hr are rated by Thermal Efficiency.
Thermal Efficiency Equation
We are interested in the steady-state Thermal Efficiency – i.e., after the flue gas temperature has warmed up and reached equilibrium. Many combustion systems do not operate in steady-state equilibrium: they cycle up and down, taking a significant time to reach equilibrium, if at all. Nearly all transient systems are significantly less efficient than ones that operate in the steady state.
Thermal Efficiency is a steady-state measure only and does not include the effects of heat loss caused by on-off cycling or transient operation. This measure is different from the Annual Fuel Utilization Efficiency (AFUE) rating, which measures the average efficiency of a system over a year. The AFUE rating takes into account the cyclic on/off operation and associated energy losses of the heating unit as it responds to changes in the load, which in turn is affected by changes in weather and occupant controls.
Thermal Efficiency Equation
We are interested in the steady-state Thermal Efficiency – i.e., after the flue gas temperature has warmed up and reached equilibrium. Many combustion systems do not operate in steady-state equilibrium: they cycle up and down, taking a significant time to reach equilibrium, if at all. Nearly all transient systems are significantly less efficient than ones that operate in the steady state.
Thermal Efficiency is a steady-state measure only and does not include the effects of heat loss caused by on-off cycling or transient operation. This measure is different from the Annual Fuel Utilization Efficiency (AFUE) rating, which measures the average efficiency of a system over a year. The AFUE rating takes into account the cyclic on/off operation and associated energy losses of the heating unit as it responds to changes in the load, which in turn is affected by changes in weather and occupant controls.
Boilers
Boilers provide hot water or steam for industrial processes, for heating spaces and for hot water. A wide range of types and sizes of boilers meet the varied needs of industrial and other facilities.
Most boilers have three main parts: a burner that converts the fuel to heat, a heat exchanger that transfers the heat to steam or water, and a boiler vessel. A chimney stack draws off the combustion by-products (flue gases), and the hot water or steam flows through a distribution system to its end uses.
Natural gas and oil are the most common fuels used in boilers. Propane, electricity, coal and biomass are also used. Electric boilers are generally found where combustion boiler fire hazards pose safety risks and where it is important to reduce air pollution.
Boiler life is approximately 25 years, so it is essential to consider both long-term fuel and maintenance costs along with initial capital costs when buying or retrofitting. Fuel costs for a new high-efficiency model can be up to 40 percent lower than for a conventional one. Over 25 years, this can be a great saving. In many cases, simply retrofitting an existing boiler can improve efficiency by 20 percent or more.
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