Are your energy bills too high? Is your home not as comfortable as you want it to be? Do you want to do more to protect the
environment? Do you have teenagers at home giving your hot water bill a
beating? Whatever your situation, this will help you to find a solution
that's right for you. This guide is primarily aimed at homeowners who
are thinking of upgrading or replacing their home's existing heating or
cooling systems. It also contains useful information for people who are
having a home built for them, and for those who want to reduce their
energy consumption in general.
While builders generally offer a
standard heating or heating/cooling package, upgrades to more efficient
equipment might be available. Familiarity with the different systems,
fuel options, their comparative prices and operating costs will help
you to review upgrade options with your builder. Remember to also ask
your builder about other energy efficiency upgrades, which can range
from extra insulation to a complete R-2000-certified home. Before being
R-2000-certified, each home is evaluated and tested to ensure a high
level of energy efficiency has been designed and built into it. There
are both financial and environmental benefits to conserving energy and
using it wisely. To help you conserve even more, this will also direct
you to resources that can help you reduce energy consumed for purposes
beyond heating and cooling your home.
A Wise Choice
The options presented will help you to
select heating and cooling systems that meet the needs of both your
lifestyle and your check book. Besides the obvious savings for you that
occur by lowering your consumption, by reducing demand for energy
through conservation or, in the case of electricity, even from shifting
consumption to times of lower demand, together we can lower the market
price for the energy that is consumed. The advantages of investing in
energy efficiency aren't only felt within your family budget– they are
realized in the cleaner environment that goes hand in hand with more
efficient systems and the wise use of energy.
Before You Start
Putting an energy-efficient heating
system into a drafty, poorly insulated house will reduce your energy
bills. But you'll notice a more dramatic saving, and even make yourself
more comfortable, if you also make your entire house more energy
efficient. How? Here are some ideas…
- Weatherstrip and caulk to seal air leaks. You may have to replace uncontrolled sources of air with designed sources to ensure proper ventilation.
- Increase insulation levels where appropriate (such as in the attic or walls) to reduce heat loss in winter and heat gain in summer.
- Open drapes on south-facing windows on sunny winter days so that the sun's energy can help heat your home, and close them in summer to help keep your home cool.
- Choose energy-efficient products when replacing windows and doors.
By making your house more
energy-efficient, your heating and cooling systems will work less, and
you may reduce the capacity needed when you replace your systems, which
means more savings for you.
Why Energy Efficiency Matters
It's good for your budget, your
comfort and our environment. Each year you spend hundreds of dollars to
heat and cool your home and to heat your hot water. By installing
energy-efficient equipment, which gives you the same comfort for less
energy, you can lower these costs. Furthermore, the lower you can make
your energy costs now, the better off you will be should energy prices
go up – and conservation reduces upward pressure on energy prices.
Whenever fuels are burned – in your
home, in a generating station to produce electricity, in vehicles or
elsewhere – carbon dioxide, nitrogen oxide and sulphur dioxide are
released. These emissions contribute to environmental concerns
including smog, acid rain and climate change. Reducing energy use
lowers the amounts of these emissions and their impact on the
environment. You can help by practicing energy efficiency and
conservation not only in heating and cooling your home, but everywhere
at home, in the workplace and in your transportation choices. Many factors can affect your annual energy bill such as size and location of your home, yearly variations in weather, efficiency of your furnace and other appliances,
thermostat settings, number of occupants, and the local cost of energy.
Are you serious about how to go about cutting your heating and cooling costs?
Follow these steps:
Heating Units and Controls
- Where appropriate, improve the insulation and air sealing in your home.
- Use this guide to help you decide what kinds of changes to your heating and cooling systems will be right for you.
- Consult with a registered heating/cooling contractor and your fuel supplier before making a final decision.
There are four common types of heating units:
- A furnace provides heat through a forced air distribution system.
- A boiler provides heat through a hydronic distribution system. (Hydronic systems are also referred to as hot water systems.)
- A space heater supplies heat directly to the room where it is located.
- A heat pump extracts heat from the air, ground or water outside the house and usually delivers it through a forced air distribution system.
Most heating systems need air for
combustion. Furnaces, boilers and space heaters that burn fuels need a
supply of air to be able to burn properly, and a vent to the outdoors
so that combustion gases can escape from the house. Electric heaters do
not need to be vented. Combustion is a two-step process: air in, and
In the past, there was usually plenty
of air leaking into a house to keep the furnace, boiler or stove
burning well. Modern homes, however, are better sealed and use
controlled ventilation, rather than uncontrolled leakage, to provide
greater comfort and energy efficiency. Vents that supply air for
heating units should never be blocked. It is important to ensure that
there is an adequate supply of combustion air available, even when
other air exhausting equipment is in use.
Venting used to be done through a
chimney. Today, however, many models of natural gas, oil and propane
equipment can be vented by pipe directly through the wall, which
installation. Remember that combustion
gases cannot escape from your home unless you provide air to replace
them. That's why venting problems can often be traced to air supply
The indoor temperature is
automatically controlled by a thermostat. Two important considerations
are location and type. Central systems are normally controlled by a
single thermostat. To achieve proper temperature control, the
thermostat must be located in an area where it will sense the “average”
indoor temperature. Locations exposed to localized temperature extremes (outside walls, drafts, sunlight, hot ducts or pipes, etc.) should be avoided.
Different types of thermostats are
available. Basic types maintain a fixed indoor temperature. However,
you can reduce your heating costs by installing a set-back thermostat
which can be programmed to automatically lower the temperature when no
one is home or everyone is in bed, and then warm up the house before
you get home or wake up. Savings will vary, but a set-back of 3ºC for
eight hours daily could reduce your heating costs by about 5%.
Where space heaters are used, each
unit will likely be individually controlled by its own thermostat –
which is usually the basic type. This allows you to keep unused areas
at a lower temperature than those areas you do use.
There are three types of distribution systems.
- A forced air system circulates warmed
or cooled air around the house through a network of ducts. It also
provides a means of distributing ventilation air.
- A hot water (hydronic) system distributes heat through hot water pipes and radiators.
- Space heaters, though not technically a distribution system, provide direct heat to the room in which they are located.
It is important that a distribution
system is properly designed, installed and operated to ensure maximum
energy efficiency and comfort levels. Try to avoid placing any part of
your distribution system outside of your home's insulation. This is
sometimes done as a simple remedy to a routing problem, but there is
always some heat loss through the wall of any distribution system. It
is better that any losses heat (or cool) you rather than your attic.
Registers in each room can be adjusted
to control the air flow. Return registers draw air from the rooms
through separate ducts back to the furnace to complete the cycle of air
flow through the
house. Leaks in forced air
distribution systems are often ignored because they normally do not
cause any obvious damage, but it is important to avoid/eliminate such
leaks. Leaks will affect a distribution system's ability to provide
comfort in all areas of the house, and leaks in some parts of the
system can result in significant energy loss and/or
condensation-related damage which may be hidden from sight.
Hot water (Hydronic) Heating
Distributes hot water from a boiler to
radiators, convectors or under-floor heating systems in each room. In
older homes, large cast-iron radiators are common. Modern systems
feature smaller boilers, narrow piping and compact radiators that can
be regulated to provide temperature control in each room.
Under-the-floor heating systems can be built into the floors of new and
These have no central heating unit or
distribution system. Instead, individual space heaters – such as a wood
stove, electric baseboards, radiant heaters or heaters fueled with oil,
natural gas or propane – supply heat directly to the room. For safety,
all space heaters except electric ones need to be vented to the
outside. An appropriately sized space heater can supply some heat to
all parts of a home if the design of the home allows for natural
distribution of heat from the heater location. In most cases, more than
one unit is required to comply with building code requirements, but
multiple units allow you to vary the temperature around the house.
Energy Sources and Equipment Options
Furnaces in forced air heating
systems, boilers in hot water systems, fireplaces and space heaters can
be fueled by natural gas. It is delivered to your house through an
underground pipeline. (It is not available in some areas.)
Most equipment fueled by propane is
similar to that fueled by natural gas. In many cases, the only
differences are one or two small components that can often be changed
by a registered
contractor to convert a unit from one fuel to the other. Propane is delivered by truck and stored in a tank on your property.
Because of their similarities, natural
gas and propane heating equipment are discussed together. The term
“gas” refers to both natural gas and propane. The cost of the two fuels
differs, so remember to check for cost comparisons.
There are three main types of gas furnaces:
- conventional (with a seasonal efficiency range of 55 to 68 per cent)
- mid-efficiency (78 to 82 per cent)
- high-efficiency (90 to 98 per cent)
Gas boilers have similar ranges of seasonal efficiency.
Older conventional gas furnaces and boilers
Some older furnaces and boilers, which
are no longer produced but are still in use, require a continuous liner
in a masonry chimney or a metal “B” vent chimney. The liner is needed
because the combustion gases contain water vapor which condenses on
masonry and causes deterioration over time. About 35 per cent of the
heat from the fuel goes up the chimney with these models.
Mid-efficiency gas furnaces and boilers
These models remove more heat from
combustion gases so that less heat escapes when the gases are exhausted
and efficiency is improved. Depending on the circumstances, they might
be vented through a wall or through a chimney.
High-efficiency (condensing) gas furnaces and boilers
These models extract so much heat from
combustion gases in order to achieve their efficiency, that they can be
safely vented through a narrow plastic pipe that runs through the wall.Gas-fueled fireplaces
Gas fireplaces are sometimes used to
provide space heating, though they are often chosen for aesthetic
reasons. There can be significant differences in energy efficiency from
to another, and the effective efficiency of some types can be significantly affected by how they are used.
Oil furnaces and boilers have a
burner, a heat exchanger and a blower or pump. Oil is delivered by
truck and stored in a tank, which is usually located in the basement.
Older conventional oil furnaces and boilers
Older, conventional oil furnaces and
boilers with a standard burner have a seasonal efficiency generally
ranging from 60 to 70%. Like older, conventional gas furnaces and
boilers, they are no longer produced. However, in an existing model
that is working well, the seasonal efficiency can be improved by
replacing the burner with a flame retention unit – usually a more
cost-effective step than replacing the entire furnace.
New oil furnaces and boilers
A typical new oil furnace or boiler
has a seasonal efficiency rating generally ranging from 78 to 86 per
cent. Many of these units can be vented through the wall.
There are free-standing oil space
heaters with a visible flame now available. There are no efficiency
standards for these products.
Electric resistance systems can
consist of a central furnace or boiler connected to an air or hot water
distribution system, radiant panels embedded in the floor or ceiling or
a baseboard space heating system. Electricity also powers heat pumps.
When electric resistance heating is used in a new home, including as a
back-up for an air source heat pump, the building code requires
the house to be built with higher minimum levels of insulation.
A heat pump is usually an
electrically-powered system that can either heat or cool by
transferring heat from one place to another. During the heating season,
a heat pump extracts heat from
either the air, ground or water
outside the house, and transfers it indoors. In the summer the
direction of the heat flow is reversed, extracting heat from indoors
and transferring it outdoors, to
provide air conditioning. Because they
satisfy a substantial part of your heating needs by utilizing already
available heat, rather than consuming electricity to generate all of
the heat you need,
heat pumps are significantly more efficient than electric resistance heating.
There are three main types of heat pumps:
- air source heat pumps
- earth energy systems
- bivalent heat pumps.
Air source heat pumps
These most commonly-used heat pumps
can provide all the cooling requirements of a home and most of the
heating needs, but they require an auxiliary heating source during very
cold weather. This can be either an electric resistance or a fossil
Earth energy systems
Also known as ground source heat
pumps, these systems transfer heat from the ground, ground water or
surface water and use it to provide home heating. For summer cooling,
the process is reversed. If desired, earth energy systems can be
equipped to provide domestic hot water year round. Electric resistance
heaters may be installed to provide supplementary heating for the
coldest days.They normally utilize
much less electric resistance heat and offer significantly higher
efficiency than air source heat pumps.
Some households use wood as their main
fuel but even more use it as a supplementary source of heat. Most of
these households are outside large urban areas where firewood is
usually less expensive than other fuels. The most common approach to
wood heating today is a wood stove or high-efficiency fireplace
installed in the main living area of the house. If the house is
medium-sized and relatively new, this kind of equipment can provide almost all the heat needed.
If you have an existing masonry
fireplace, a high-efficiency fireplace insert could be a good option.
And many models offer the pleasure of a visible wood fire.
Older or larger houses may need the
additional heating power offered by a wood-burning furnace. If your
present heating system is a forced air furnace that uses a more costly
fuel, you might want to consider an add-on wood furnace. It is
installed beside the existing furnace and the duct work is modified so
that it can be shared by both furnaces. Combination wood/oil or
wood/electric furnaces are options for new or replacement systems.
Stoves that burn pellets made from wood or agricultural crops such as
corn kernels are also available. Pellets are automatically fed into the
burner and the householder simply dials in the required temperature on
When shopping for wood-burning
equipment, visit several wood heat retail stores and discuss appliance
selection, location and installation with a knowledgeable
salesperson.Always buy wood-burning equipment that is certified for
safety. It is also preferable to buy equipment that has been certified as meeting the U.S. Environmental Protection Agency (EPA) or Canadian CSA-B415 emission standards. These certified wood-burning appliances produce one-tenth of the chimney emissions and one-third higher efficiency than earlier units.
“Outdoor” wood furnaces or boilers are
also on the market. They may appear attractive, because they will burn
low cost material you would not think of putting in an indoor appliance
and can burn for long periods between refueling. However, they can be
low on efficiency and high on emissions.
Like wood, solar energy is a renewable
resource. Solar heating does not involve the combustion of fuels, so it
does not produce environmentally-harmful emissions. It can be as simple
as south facing windows serving as passive solar collectors. Passive
solar heating is free and should be an important consideration in the
design of homes. Homes built to high levels of energy efficiency and
designed to make the most use of free solar heating can save hundreds
of dollars a year on energy bills.
Other energy sources
Residential systems are available to
generate electricity from sunlight or wind. In certain situations, such
as remote locations, one of these may be the most practical option. In
addition, the government is establishing standardized processes and
technical requirements which will require electricity distributors to
allow customers with qualifying generation equipment to supplement
their utility electricity needs with power they generate themselves.
Cooling Systems (air conditioning)
Two types of units cool an entire
house: a central air conditioner or a heat pump. If you only need to
cool a specific area, a window air conditioning unit could be your most
energy-conserving choice. Regardless of what type you are considering,
remember that models will vary in efficiency ratings and efficiency has
a direct impact on operating costs, so optimizing efficiency should be
a priority. Consider buying an ENERGY STAR®-qualified model.
If you decide you want to cool your
entire house, you should consider which system to install – central air
conditioning or a heat pump – when reviewing your home's heating needs.
An air conditioner is actually a heat pump that can only cool.
*Remember: your heating decisions can affect your cooling options.
Duct work for central air
Duct work is generally needed to carry
cool air throughout the house in a central air conditioning system. If
you have a forced air heating system you can usually use the same ducts
for cooling. If you do not have duct work, you can look into installing
it or consider air conditioning technologies that have been developed
for homes without ducts. These alternatives are more costly, so if you
are considering them, investigate your options with your
Mini splits are systems suited to
homes without a central air-distribution system. No duct work is
required. The system consists of two components: an outdoor condensing
unit, and an indoor evaporator and fan. The indoor section can
frequently be mounted on any interior or exterior wall, and is much
quieter than a window unit.
Window air conditioners are effective
if you only need to cool a specific area of your home. They will cost
less to install than a central air conditioning system. If you don't
have duct work, they might be your most practical choice. It is
important to match the capacity of the window air conditioner with the
size of the area to be cooled. Window units should either be covered in
winter or, better still, removed to minimize heat loss.
Other Ways to Cool Your House
The following measures will help keep your home more comfortable:
Hot Water and How to Heat It
- Install ceiling fans to circulate air.
- If you're planning for the long term, plant trees that lose their leaves in the fall on the east, south and west side of your house.
- Close the drapes or blinds on south and west-facing windows during sunny summer days to reduce heat gains.
- Turn off lights and appliances when they are not in use.
- Install awnings for patio doors and windows that face the sun.
- Open windows in the evening and at night during the summer months.
There are several
water-heating options available to you. While you are taking steps to
save on home heating, don't forget to see what you can do to lower your
water heating costs. Check with your fuel supplier for more
information, and consider alternatives to your current method.
Storage-type water heaters
Most homes have storage-type water
heaters in which water in a tank is heated by a gas or oil burner or by
electric elements. Traditional storage heaters have been improved with
such features as through-the-wall venting for combustion units and
better insulation, making them less expensive to operate. Units
designed to give even greater efficiency are now available.
Instantaneous water heaters
Instantaneous water heaters which heat
water as needed and have no storage tank are available, but not widely.
They require little space, but they usually cost more than storage-type
water heaters and more than one unit might be required to meet your
needs. For electric instantaneous water heaters, upgraded wiring is
Integrated (combination) hot water systems
Systems that combine space heating and
water heating are becoming more popular. Water can be heated with a
boiler or a storage-tank water heater. The hot water can be used for
space heating as well as domestic hot water needs. Space heating
methods include baseboard radiators, in-floor radiant heating and
forced air heating when piped to an air handler. Some of these systems
can also be used for pool and spa heating and snow-melting
applications. Combo systems vary widely in efficiency and must be
carefully designed to give satisfactory service.
Solar water heaters
In solar water heaters, energy from
the sun is collected by solar panels and transferred by circulating
fluids to a storage tank. These heaters are typically used with an
electric water heater, or one fueled by oil, natural gas or propane,
which acts as a back-up for overcast days. Solar collector panels can
be mounted on any unobstructed roof, wall or ground frame that faces
southeast and southwest. Solar water
heaters are designed to provide between 35 and 75% of your hot water
needs, with the back-up providing the balance.Replacing Your System
Review your options, consider the pros
and cons of different equipment and fuels, and compare installation and
operating costs. Now get ready to improve your existing system, and
it's time to select a contractor. Here are some tips:
- Look for a registered contractor
Your contractor will supply and install your equipment. Proper installation is essential for the safe, efficient and economical operation of your system. Electric equipment must be installed by a licensed electrician and all electrical work must be inspected.
- Get estimates from several contractors.
Prices can vary significantly among contractors. Ask each firm for a written estimate covering the following items:
- The total cost and a listing of all necessary work including improvements to the existing system and the provision of combustion air if applicable
- Heat loss/gain analysis
- The size and seasonal efficiency of the unit, and sound ratings if applicable
- Responsibility of the contractor or homeowner for:
- Obtaining permits and paying related fees
- Removing and disposing of old equipment
- Arranging for such work as installation of gas supply
- Arranging necessary inspections
- A work schedule and completion date
- Guarantees, warranties and service contracts
- Terms of payment
- Evidence of an electrician's licence as appropriate
Use costs (both installed and
operating), work schedule, warranties and service as the basis for your
decision. Ask the contractors you are considering for references, and
follow up by contacting previous customers. Ask what they think about
the contractor, fuel supplier and the options you are considering.
- Choose the right equipment
In order to correctly size new heating
and cooling equipment, your contractor must analyze how much heat is
lost from your home in winter and gained in summer. Ask for this heat
loss/gain analysis in writing, including the method used to perform the
calculation. This calculation should take into consideration such
factors as the size of the house, its level of insulation and the
condition of windows and doors. If the heat loss and gain is
significant and you haven't already taken steps to increase the energy
efficiency of the house, now is the time to do it.
Avoid the temptation to simply choose
the same size equipment that already exists in your house without doing
a heat loss/gain analysis. Your home has likely been altered over the
and the system might even have been
the wrong size at the start. An oversized unit will usually operate
below peak efficiency, and both oversized and undersized units can
adversely affect the
comfort of your home. Any installation
involving combustion equipment should include steps to ensure that
there will be an adequate supply of air for combustion and venting, and
that other air exhausting equipment will not cause problems.
Changing Your Water Heater
Size is an important consideration
when selecting new hot water equipment. A larger family is likely to
use more hot water. A “downsized” household – for example, an older
couple whose children have grown up and moved into their own homes –
will no longer need a water heater meant to supply the needs of four or
more people. By practicing water conservation – for example, by
installing energy-efficient showerheads and aerators on taps and using
cold water in your washing machine – you can substantially reduce your
hot water usage.
Steps to installing a hot water tank
Contact your local fuel supplier or
contractor and ask for the efficiency ratings of the models you are
considering. When you have selected a unit just big enough to meet your
household needs, your fuel supplier or contractor can arrange for a
qualified serviceperson to install the water heater. If you have an
electric hot water tank, wrap it in an insulating blanket. Make sure
the blanket is certified for use on your heater and is properly
installed. Insulate both the hot and cold water lines of the tank and
consider installing a heat trap. Be careful not to insulate the pipes
too close to the flue of a fossil-fueled tank. Ask your fuel supplier
about any water heating cost-saving programs they offer. Some suppliers
do some of the work at little or no cost to you.
Glossary of terms
Here is a quick overview of terms used
in this guide and that you'll need to know as you gather information
about your home heating and cooling options.
AIR SOURCE HEAT PUMP
A heating-cooling unit that transfers heat in either direction between the air outside a home and the indoors.
AIR SUPPLY FOR COMBUSTION
The air that a furnace, boiler or space heater requires to burn fuel.
A thermostat that controls the water temperature in a boiler.
The heating unit used with a hot water (hydronic) distribution system.
CENTRAL AIR CONDITIONER
A unit that cools an entire house by removing heat from the inside air and releasing it outside.
Devices such as a thermostat that regulate a heating or cooling system.
CONVENTIONAL GAS FURNACE OR BOILER
A gas heating unit with an annual fuel
utilization efficiency (AFUE) less than 70%. It exhausts through a
masonry chimney (which should be lined) or metal “B” vent.
COST-EFFECTIVE HEATING/COOLING SYSTEM
One that produces good value for money after all costs (purchase, installation, financing and energy charges) are considered.
The components of a heating or cooling system that deliver warmed or cooled air, or warmed water, to the living space.
DOMESTIC HOT WATER
Hot water used for household purposes.
EARTH ENERGY SYSTEM (ground source heat pump)
A heat pump that transfers heat from
the earth or ground water in cold weather and transfers it to the house
through an underground piping system for space heating, cooling or
water heating. The process reverses in warm weather, and heat is
discharged to the ground or water.
ELECTRICAL RESISTANCE HEATING
Heat produced by passing electricity through a resistor.
FLAME RETENTION HEAD BURNER
A higher-efficiency burner in an oil
furnace. It produces a hotter flame and operates with a lower air flow,
thus reducing heat loss up the chimney.
The fluids commonly used in
refrigerating and air conditioning equipment to create the cooling
effect. These fluids can damage the environment.
A distribution system in which a fan circulates air from the heating or cooling unit to the rooms through a network of ducts.
A naturally occurring carbon or
hydrocarbon fuel such as natural gas, propane and oil, formed by the
decomposition of prehistoric organisms.
A heating unit that uses a forced air distribution system.
GROUND SOURCE HEAT PUMP
Another term for an Earth Energy System.
A structure that transfers heat from
one gas or liquid to another gas or liquid. For example, the hot
combustion gases in a furnace to the circulating household air or, in a
boiler, to the circulating hot water.
HEAT RECOVERY VENTILATOR (HRV)
A device used in central ventilation
systems to reduce the amount of heat that is lost as household air is
replaced with outside air. As fresh air enters the house, it passes
through a heat exchanger heated by the warm outgoing air stream and is
HIGH-EFFICIENCY (condensing) FURNACE OR BOILER
A heating unit with an annual fuel
utilization efficiency (AFUE) of 90% or more. It has a second stainless
steel heat exchanger that removes additional heat from exhaust gases.
Water vapor condenses as the exhaust cools. The unit vents through a
narrow plastic wall pipe instead of a chimney.
A distribution system in which hot
water is circulated through a network of pipes to radiators, wall
panels or an under-floor heating system.
The total of the purchase price and the installation costs of equipment.
INSTANTANEOUS WATER HEATER
A device that heats water as required but does not store it. The unit is usually located near the point of use.
INTEGRATED (combo) HOT WATER SYSTEM
A system that provides both space and water heating from a single heat source.
A unit of electrical power used to measure the heating capacity of electric equipment. One kilowatt (kW) equals 1,000 watts (W).
MID-EFFICIENCY NATURAL GAS OR PROPANE FURNACE OR BOILER
A gas heating unit with an annual fuel utilization efficiency (AFUE) of 78 to 82%. Some models exhaust
through the basement wall.
NEW OIL FURNACE
Efficiencies (AFUE) range from 78 to 86%. Has flue gases that may be exhausted through a chimney or a side wall vent.
A performance standard for new homes
under a voluntary government/industry program. Builders meet the
standard by offering an integrated package of features designed to meet
the R-2000 requirements. The package includes high insulation levels,
air-tightness, heat recovery ventilation and efficient heating/cooling
Replacement of one or more components of an existing system.
A performance rating that considers
the heat (or ‘cool') actually delivered to the living space, the total
energy available in the fuel consumed, and the impact the equipment
itself has on the total heating or cooling load through an entire
heating or cooling season. HSPF, AFUE, SEER and EF are seasonal
seasonal energy efficiency ratio
A programmable thermostat with a built-in timer. You can adjust it to vary household temperature automatically.
A heating unit that supplies heat directly to the room where it is located and is not connected to a distribution system.
STORAGE-TYPE WATER HEATER
A tank that heats and stores hot water.
A measure of the cooling capacity for central air conditioners and heat pumps.
Efficiency Ratings: AFUE, COP, HSPF, SEER & EER
Take a few moments to familiarize yourself with the efficiency ratings you'll find on various pieces of equipment.
Boilers and Furnaces
Rating to look for: AFUE
The annual fuel utilization efficiency
(AFUE) of furnaces and boilers measures their performance over a
typical heating season. It takes into account things like on-and-off
cycles and heat loss through the chimney or vent, and is the most
useful furnace and boiler rating available. The higher the rating, the
more efficient the unit.
There is a second efficiency rating
for furnaces and boilers and it is known as steady-state efficiency. It
is higher than an AFUE rating but it's not as helpful. It measures the
equipment's performance after it has been running a short while and all
components have reached their normal operating temperature. The steady
state efficiency of furnaces and boilers is determined by
comparing the amount of heat that's
available in the fuel to the amount that is converted into usable heat,
but it does not include off-cycle losses.
Advanced equipment which is certified
as meeting the EPA or CSA-B415 emissions standard normally exceeds 60%
and averages 70% efficiency. Conventional wood-burning appliances which
are not certified as low emission average 50% efficiency, with a range
of 35 - 70%. Although some wood burning equipment is specifically
certified for efficiency, most is not.
Also, most wood-burning appliances are
manually operated, not automatic, and so the practices of the operator
will affect the efficiency actually achieved.
Ratings to look for: COP, HSPF
Earth energy systems are rated for
heating efficiency by comparing them to electric resistance heat. The
measurement used is called the coefficient of performance – COP – and
is determined by dividing the heat output by the energy input. Since
the COP of an electric resistance heater is 1.0 – which means that the
same amount of energy that goes into it as electricity comes out as
heat – any rating higher than 1.0 means that for the same amount of
electricity going in, more heat comes out. Look for a COP of 3.1 or
The heating efficiency rating for an
air source heat pump is called the heating seasonal performance factor
(HSPF). This is determined by dividing the total heat provided during
the season (in BTU) by the total energy consumed by the system (in
watt-hours). The higher the rating, the more efficient the heat pump is
over the entire heating season. Look for an HSPF of more than 5.9.
Air conditioners and air source heat pumps
Ratings to look for: SEER
A SEER rating, which stands for
Seasonal Energy Efficiency Ratio, tells you the cooling energy
efficiency of air conditioners and air source heat pumps. The rating is
determined by dividing the total cooling provided during the season (in
BTU) by the total energy consumed by the system (in watt-hours). The
higher the rating, the more energy-efficient the unit. SEERs for new
central air conditioners and air source heat pumps currently range from
10 to 17. For room air conditioners, the range is 8 to 12.
Earth energy systems
Ratings to look for: EER
If you want to know how efficiently an
earth energy system can cool, look for the letters EER, which stand for
energy efficiency ratio. EER ratings are determined by dividing the
cooling output of the ground or water source heat pump (in BTU/hour) by
the power input (in watts). Look for an EER of at least 10.5.
Hot water equipment
Storage-type Hot Water Heaters
An energy factor (EF) is used to rate
the energy efficiency of storage-type hot water heaters. Both on-cycle
efficiency and off-cycle losses are taken into account, which makes it
a seasonal rating. The higher the EF, the more efficient the unit. You
can expect the following energy factor ranges for new storage-type
- Gas 0.56 to 0.86
- Electric 0.87 to 0.98
- Oil 0.53 to .68
A storage-type water heater added to an earth energy system will normally have an energy factor of 2.7 to 3.1.