Consumer Heating and Cooling Education Centre

Furnace Selection
Heating Appliance Selection
Comparing Mid-Efficiency and Hi-Efficiency Furnaces
Replacing A Furnace Using An Existing Chimney
How Does A Heat Pump Work?
Venting Of Direct Vent Gas Appliances

FURNACE SELECTION
Question:
I am looking to replace my existing furnace as it is 24 years old and I have been told it may not last the winter. I have had three companies give me a price, however I am confused because I am getting three different stories.

My house is 1,800 square feet and my old furnace is 100,000 BTUs. One company wants to put in a 90,000 BTU "Brand X" mid-efficiency furnace, another an 80,000 BTU "Brand Y" mid-efficiency furnace and the other a 65,000 BTU "Brand Z" hi-efficiency furnace. Could you please tell me which furnace I should be putting in my home?

Reply:
HRAI Canada is a member-supported trade association and therefore cannot recommend one product over another.

HRAI does recommend that, before you make a final decision on any replacement equipment, you have a proper heat loss calculation done on your existing house. Historically, many furnaces have been oversized as heat loss calculations were not done and installers put in larger furnaces "just to be safe". Once a contractor has done a proper heat loss calculation the appropriate furnace can be selected to meet the heat required for your home. Properly sized equipment is important as it will have less frequent cycles which means you will get the most efficient performance and less wear and tear on the system.

HEATING APPLIANCE SELECTION
Question:
I am building a new house and to get my building permit I hired a company to do a calculation to determine the proper size of furnace for the house. I was told I needed 54,000 BTU's (whatever that means) to heat my house. A heating contractor I have talked to said they would install a 65,000 BTU hi-efficiency furnace. This seems to me to be too large and would cost me more to heat my house. How can I tell if this is the proper size furnace?

Reply:
First, a BTU or British Thermal Unit is a measurement of heat used to determine the heating requirement of the house and match this with the size of equipment.

The heating equipment is sized by its 'input' which is the number of BTUs created by burning the fuel, whether the fuel be natural gas, oil or propane. The actual amount of heat available to heat your home is the 'output' of the equipment. The output is always lower than the input due to heat losses during the heating process within the appliance and heat lost to the outdoors through the chimney and other parts of the house.

All furnaces sold in Canada are rated by the Annual Fuel Utilization Efficiency ratio (AFUE), which is the industry standard that has been designed to reflect the efficiency of a furnace installed in a home setting. The AFUE is the percent of heat produced for every dollar of fuel consumed. Like the miles per gallon on your car, the higher the AFUE rating, the lower your fuel costs. These ratings are found in the EnerGuide section of the manufacturers' literature for each model of furnace.

If the calculated heating requirement for a home is 54,000 BTUs, this is the minimum output required for the heating system. A furnace having a rating of 65,000 BTU (input) and an AFUE of 88% (which it must have to be classified as hi-efficiency) will have an output of approximately 57,200 BTUs and would not be oversized for the application. The national standard of Canada CSA F280 "Determining the Required Capacity of Residential Space Heating and Cooling Appliances" states that an appliance is not considered to be oversized unless it exceeds 140% of the calculated heating requirement. If your home requires 54,000 BTUs an appliance with an output of 75,600 BTUs can be used.

COMPARING MID-EFFICIENCY and HI-EFFICIENCY FURNACES
Question:
I am replacing my old furnace, which my contractor tells me it is 65% efficient, and I am trying to decide whether to purchase a mid-efficiency or a hi-efficiency furnace. The cost of a hi-efficient furnace is quite a bit higher than the mid-efficiency. Is it worth it to spend the additional money for the hi-efficiency furnace?

Reply:
According to Natural Resources Canada, EnerGuide program for furnaces, the mid-efficiency rating is between 78% and 82% AFUE while the hi-efficiency furnace is between 88% and 97% AFUE, depending on the model of the furnace. Either furnace type will provide you with operating cost savings over your old furnace as long as the furnace is sized and selected properly.

All furnaces sold in Canada are rated by the Annual Fuel Utilization Efficiency ratio (AFUE), which is the industry standard to reflect the efficiency of a furnace installed in a home setting (see answer to previous question). The AFUE is the percent of heat produced for every dollar of fuel consumed. Like the miles per gallon on your car, the higher the AFUE rating, the lower your fuel costs. These ratings are found in the EnerGuide marking on the manufacturers' literature for each model of furnace.

Another factor that should be considered when looking at a replacement furnace is the electrical usage required to run the fans and motors. The amount of electricity used varies greatly, depending on the model of furnace. Some newer furnaces have Electronically Commutating Motors (ECM) available, which can reduce the electrical consumption of the furnace motor by as much as 60% over the standard motor.

Servicing of mid- and hi-efficiency furnaces should also be considered during the purchase decision. HRAI recommends that all heating systems should be inspected and serviced on at least an annual basis and hi-efficiency furnaces may have slightly higher maintenance cost, as they are more complex than the mid-efficiency.

It comes down to a financial "pay back" decision on your part. Does the additional savings provided by the hi-efficiency furnace justify the initial additional cost?

REPLACING A FURNACE USING AN EXISTING CHIMNEY
Question:
I need my old furnace replaced and one contractor I was talking with said I needed my chimney "lined". Could you tell me what this means and if it is necessary?

Reply:
Modern mid-efficiency furnaces are vented either by using existing chimneys or by installing a separate vent that goes through the external wall of the house to the outside. Should you decide to use the existing chimney, there are certain considerations that must be taken into account.

Residential furnace technology has advanced significantly in recent years producing higher efficiencies. Modern furnaces transfer more heat into your home and less heat up the chimney in comparison to older, less efficient units. This means your existing chimney might be too large for the new furnace, preventing proper movement of the combustion gas and causing condensation problems inside the chimney.

Older, less efficient, furnaces produce higher combustion gas temperatures and more water vapour to be vented out the chimney. The combustion gases from today's higher efficiency furnaces are cooler and contain a smaller volume of combustion gas. This means the chimney is cooler and water vapour could condense on the inside walls of the chimney, which can cause damage to a masonry chimney. (e.g. the water vapour can freeze and eventually damage the bricks and mortar, allowing the products of combustion to enter the home).

If you have a masonry chimney, a properly sized and certified metal liner kit should be installed by a reputable HVAC contractor. Should you have a metal chimney that is corroded or improperly sized for the new furnace, the chimney should be replaced or fitted with a properly sized liner.

HOW DOES A HEAT PUMP WORK?
Question:
I am planning to build a house and have been told that one of the most efficient ways to heat and cool the house is with a heat pump. I would like to know more about how a heat pump works and the cost to have one installed.

Reply:
There are two types of heat pumps, which operate in the same way but utilize different heat sources. Air-source heat pumps extract heat from the outside air and the ground-source or earth-coupled heat pumps extract heat from either ground water (open loop) or ground itself (closed loop). For more information on heat pumps and how they work, visit the Natural Resources Canada website.

Should you wish to proceed with a heat pump as your home heating system, it is recommended that you contact a qualified complying HVAC contractor regarding the sizing, selection and cost of a heat pump system. For a list of qualified complying contractors in your area visit HRAI's Contractor Locator.

VENTING OF DIRECT VENT GAS APPLIANCES
Question:
I wish to install a direct vent gas fireplace but the only place the vent can be located is beneath an outdoor balcony. The contractor has told me that this cannot be done as the regulations will not allow this.

Is this true? And do the manufacturer's specifications override the regulations?

Reply:
The installation you have described would not be in compliance with the safety codes and standards of Canada and therefore would not be accepted by any gas inspector. CSA B149.1-00 "Natural Gas and Propane Installation Code" provides specific direction regarding vent termination. Section 7.14.8 states that "A vent shall not terminate underneath a veranda, porch or deck unless (i) the veranda, porch, or deck is fully open on a minimum of two sides beneath the floor; and (ii) the distance between the top of the vent termination and the underside of the veranda, porch, or deck is greater than 1 ft. (300 mm)."

The manufacturer's specifications and/or installation instructions must be "certified" through an investigation and identification process by a designated testing organization as conforming to recognized standards, requirements, or accepted test reports. These documents cannot override any code or standard regulations but rather must comply with these regulations.

How IAQ Can Affect Your Health
Mold And Mildew Control With Fresh Air

HOW IAQ CAN AFFECT YOUR HEALTH
Question:
We moved into a newly renovated older home about 2 years ago and it seems that one or more of the family is ill most of the time during the winter months since we moved in. I was concerned that the heating system was leaking fumes, however after inspection and testing by a heating contractor, nothing was found defective. I have heard about "Sick Building Syndrome". Is there such a thing as "Sick House Syndrome"?

Reply:
Yes, although it is not labeled as such. Poor indoor air quality in residential homes does cause discomfort and in some instances illness.

Few people recognize that they spend twice as much time at home as they do at the workplace and although many are aware of poor air quality at work, they don't realize the same situation could occur at home. Children and stay-at-home parents can be exposed to poor indoor air quality for an even longer period of time. Research has shown that exposure to air pollution can be up to 100 times higher indoors than outdoors due to tightly sealed homes and the lack of outdoor air.

Indoor air quality is more of a concern today than in the past, as homes are being built "tighter" to reduce air infiltration or leakage and therefore to be more energy efficient. Also, many homeowners are "tightening-up" their existing homes with better insulation, sealing cracks, weather-stripping, upgraded windows and high quality doors due to increasing energy costs. Unfortunately, as the homes become "tighter", the indoor air quality suffers as the exchange of indoor and outdoor air becomes restricted. Indoor pollutants build up and moisture is trapped, which can encourage the growth of mildew and molds. The effects of these elements are particularly prominent during the winter months, as people are less likely to open windows and do not enter or leave their home as much during this season.

One method of improving the indoor air quality is to remove the stale indoor air and replace it with outdoor air by way of a mechanical ventilation system coupled with effective air filtration. Your home should be evaluated by a qualified ventilation contractor who can design and install the most effective system for your requirements. We suggest you visit HRAI's Contractor Locator to obtain a list of qualified contractors that service your area and can help you improve your indoor air quality.

MOLD AND MILDEW CONTROL WITH FRESH AIR
Question:
Some of my family suffers from asthma and I find that it is just as bad in the winter as in the summer. This surprises me because it is expected that during the summer, asthma attacks can be caused by pollution, pollen, or high temperatures and humidity. In the winter these conditions do not exist and we spend more time indoors. So why are my children still having difficulty? Is the air in their school causing the problem and if so what can we do to improve the situation?

Reply:
The problem may or may not be poor air quality in the school. It has certainly been found that there are problems in some school environments and that should be investigated, but another avenue for investigation may be closer to home. Your children spend about 6 hours a day in the school environment and close to 18 hours in the home environment during the winter months. The home environment should be investigated as well.

Chemicals in carpets, fresh paint, household cleaners, furniture and building materials all can contribute to poor indoor air quality in your home. One of the least recognized contributors to poor air quality is moisture. This can be generated by activities including baths, showers, laundry, dishwashers, or just the moisture given off by the people living in the home. The accumulation of moisture from these sources can contribute to the growth of molds and mildew, which have been identified as asthma and allergy stimulants in many surroundings.

To control these contaminants, and therefore reduce or eliminate their effects, the contaminated air can be removed (exhausted) and replaced (supplied) with outdoor air by means of a mechanical ventilation system. This means installing properly sized and installed fans to push the air out of the home and making the necessary provisions to introduce outdoor air into the living area. The introduction of dry outdoor air into the home will replace the warm moist air that encourages the growth of molds and mildew and well as dilute the chemical irritants from other sources.

There are several methods of providing adequate ventilation to improve the air quality in your home. You should contact a qualified ventilation contractor to evaluate your specific needs and propose the best solution. To assist you in identifying a qualified contractor, HRAI has established a Contractor Locator.

Heat Recovery Ventilator Selection
Modifying Heating & Ventilation Equipment
Heat Recovery Ventilator Performance

HEAT RECOVERY VENTILATOR SELECTION
Question:
My husband and I are presently renovating our 23 year-old home and will be installing an air exchanger in it for the first time. We have a choice of two Heat Recovery Ventilators (HRV's) to use. Could you recommend one or the other for our 2100 square foot bungalow, and could you suggest a particular model?

Reply:
HRAI is a national trade association of manufacturer, wholesaler and contractor member companies in the heating, ventilation, air conditioning and refrigeration (HVACR) industry. HRAI therefore cannot provide any recommendations on specific brands of HVACR products to purchase.

One point to consider in this decision is to ensure the HRV is performance tested and certified by the Home Ventilating Institute (HVI). You can visit the HVI website at www.hvi.org to confirm that the model is certified and will provide the necessary ventilation air required for your home if it has been installed correctly.

Possibly as important as the brand you choose is the selection of the contractor designing and installing the equipment. A poor design or installation will not give you the results you are looking for. HRAI trains and certifies contractors on the proper methods for the selection and installation of ventilation systems and we recommend that you use an HRAI certified person. You can find a list of certified persons for your area on the HRAI website at www.hrai.ca under SkillTech Academy - Canadian Certification Listings or ask your contractor for verification that their technicians are HRAI certified for residential ventilation.

MODIFYING HEATING & VENTILATION EQUIPMENT
Question:
We have a heat recovery ventilator installed in the loft that we would like to shut off at the front door when we are leaving (along with the furnace fan). I put a switch on the whole circuit that provides power to that part of the house but several useful lights are also on that circuit, which is a minor problem when the fans are off.

Can I connect a separate switch directly wired to the HRV control circuit to remotely turn the machine off when I'm not home?

Reply:
The Canadian Electrical Code requires that disconnect devices be in the line of sight of the appliance being served. Your proposal to add a remote disconnect will contravene the code. Furthermore any alteration of the control wiring on this equipment may void the warranty of the appliances and/or negate the CSA certification, making the appliances illegal.

We recommend you contact the equipment manufacturer or a qualified heating contractor before making any modifications to your heating system and suggest that the installation of a programmable thermostat may provide you with the same results.

HEAT RECOVERY VENTILATOR PERFORMANCE
Question:
Prior to purchasing our home we had a home inspection. The inspector informed us that the home had an HRV and that it was not running. The motor seems to be running, but we don't think it's working properly.

How can we tell if a HRV is functioning properly?

Reply:
We recommend that you contact a qualified heating and ventilation contractor to analyze the installation. To locate a qualified complying contractor in your area you may wish to visit HRAI's Contractor Locator and use the search engine by typing in your postal code, select Residential Ventilation and click search.

The volume of ventilation air for residential applications is very small compared to a forced air heating system. The average home may only require 90 to 100 cubic feet of outdoor air per minute to provide adequate fresh air. The amount of air taken from a room (approximately 10 cubic feet of air per minute) would not be enough to hold up a piece of paper and at the supply air grille the volume will be just enough to move a tissue. Your ventilation system may just require balancing or flow adjustments but this must be done by a qualified contractor to ensure the system is operating at its optimum performance.

Replacing Your Central Air Conditioning Equipment
Central Air Conditioning Noise
Air Conditioning Refrigerant Update
"HVAC EnerGuide" and "Energy Star" Programs
How To Find A Qualified Air Conditioning Contractor
Air Conditioning Service

REPLACING YOUR CENTRAL AIR CONDITIONING EQUIPMENT
Question:
We have an air conditioning unit that is approximately 12 years old and we are looking at replacing it with a new unit before it packs it in completely. Some contractors are telling us that both the outdoor unit and the indoor coil need to be replaced, while others are saying we can just replace the outdoor unit. Could you give us some direction? We want to do the right thing but don't want to spend more if we don't have to.

Reply:
Your decision will come down to four factors: efficiency, reliability, warranty and initial cost.

All central or "split system" air conditioner units are specifically designed to work with matching indoor and outdoor components for optimum efficiency and performance. Air conditioner units will "work" with indoor units other than those for which they have been specifically designed; however, the result can be a compromise in system performance and efficiency.

If the outdoor unit is 12 years old and needs to be replaced, the indoor unit is just as old and has been subject to the same amount of wear and tear. Though there is more cost, replacing both units now means you may not have to replace the indoor unit in the near future and the new equipment warranty will cover the entire system.

Whichever course you decide, it is extremely important that you have the replacement performed by a qualified contractor to ensure a quality installation and maximum system performance.

CENTRAL AIR CONDITIONING NOISE
Question:
Last year we installed a new furnace and air conditioning unit. My question is about the air conditioning. Our unit is situated next to the house and has a 6-ft. high fence on both sides. However, the unit appears noisier than others we know of, because, we believe the sound is bouncing off the fences and/or the wall and being directed in one direction. Is there a way to reduce or eliminate this noise?

Reply:
Air conditioning units are mechanical devices, which generate both air noise and mechanical noise. The air noise is created by the outdoor fan and the mechanical noise is generated by the compressor inside the outdoor unit. The installed location of the unit can influence the noise level significantly, as may be the case in your situation.

We do not know of any product that is available to the homeowner to reduce the noise in this situation. On some products the fan blade can be changed for a different configuration to reduce the air noise and there are compressor shrouds that can reduce the mechanical noise. However both of these options must be performed by a properly qualified contractor (visit HRAI's Contractor Locator for a list of qualified contractors in your area) to ensure the work is done properly and safely and that the warranty on the product is not voided.

For more information on the recommended installation locations and equipment parameters, click Household_AC_Noise. (PDF. Opens in new window)

AIR CONDITIONING REFRIGERANT UPDATE
Question:
I am looking at having a central air-conditioning system put in my home and have some concerns about what the sales people are telling me regarding the refrigerant gas used in the air conditioner. Some people are telling me that the old gas used in the past (I believe it is called R22) will not be available in a few years and, therefore, I should buy a unit with a new, environmentally friendly, gas. These new units are substantially more expensive, so I would like to know if what they are saying is true about the old gas. I don't want to buy something I can't use in a couple of years, yet I don't want to pay more than I have to.

Reply:
The gas you are referring to is called "refrigerant". It is used to transfer the heat from inside your home to the outdoors through your air conditioning system. The HCFC-22 or R22 refrigerant is, and has been, the most commonly used refrigerant in residential air conditioning systems; however, it is designated as an "ozone depleting substance" and the industry will begin to phase out its use starting in 2004. This means that R22 will be available on a gradually declining basis until 2020 when the refrigerant will no longer be manufactured. As the supply of R22 decreases, the cost for replacement R22 will most likely increase. In addition, new air conditioning equipment containing R22 will not be manufactured or imported after 2010. You should factor this information into your purchase decision.

"HVAC EnerGuide" and "ENERGY STAR" PROGRAMS
Question:
Due to escalating energy costs, I am planning an extensive renovation to my existing home, including insulating, upgraded doors and windows and a new heating and air conditioning system. I am having a difficult time finding information regarding the heating and cooling equipment relating to energy efficiency of the different systems. Could you give me some direction as to where to start?

Reply:
There are two programs available to assist consumers in making informed decisions about energy efficiency regarding their heating and air conditioning system selections: the "HVAC EnerGuide" and "Energy Star" programs.

EnerGuide's rating system provides you with a standardized method of comparing the energy efficiency of different models and brands of heating and air conditioning products. The EnerGuide rating label that can be found in manufacturers' product literature identifies the efficiency range of gas, propane and oil furnaces, central air conditioning systems and air-to-air heat pumps. For further information on EnerGuide visit Natural Resources Canada's website at http://oee.nrcan.gc.ca/Equipment.

The ENERGY STAR High Efficiency program was designed to aid consumers in identifying the most energy-efficient HVAC products on the market. The ENERGY STAR label will only appear on the product literature of a product that meets the program's efficiency criteria. Gas furnaces are required to be 90% AFUE or higher to qualify. Central air conditioning systems and air-to-air heat pumps are required to have a SEER rating of 12.0 or higher. For information on the ENERGY STAR HIGH EFFICIENCY Program visit the Office of Energy Efficiency (OEE), Natural Resources Canada at http://oee.nrcan.gc.ca/energystar.

The Annual Fuel Utilization Efficiency (AFUE) for furnaces compares the yearly or annual energy output to the annual energy input. The higher the AFUE rating, the more efficient and cost-effective the furnace. The Seasonal Energy Efficiency Ratio (SEER) for air conditioners is calculated by dividing the cooling capacity of a continuously operating air conditioner by the electric power input. The higher the SEER, the less your unit will cost to operate.

It is also recommended that you have a heat loss calculation done using the upgraded values of your renovation materials prior to selecting any of the mechanical equipment. This calculation is available through your local qualified contractor and will help ensure proper sizing and operating efficiency of your new system.

HOW TO FIND A QUALIFIED AIR CONDITIONING CONTRACTOR
Question:
I am considering having my furnace replaced and having air conditioning added in my house and would like to know that it is going to be installed properly. Could you direct me as to what to look for when I am selecting an installer?

Reply:
In all provinces of Canada (with the exception of Newfoundland) the Refrigeration and Air Conditioning trade is compulsory and an air conditioning system must be installed, maintained or serviced by a journeyman refrigeration and air conditioning mechanic or apprentice under a journeyman. This does not apply to domestic appliances (e.g. fridge or freezer) or window air-conditioners, however it does apply to residential split systems (central air conditioning) of any capacity. The only exceptions to this are in the Provinces of British Columbia and Alberta, where the installation of residential air conditioning systems is exempted from the trade requirements. A Certification of Qualification is issued by the applicable provincial Ministry upon successfully passing a provincial examination and in most cases the completion of the apprenticeship program. The consumer has the right to request proof of qualification from the installer or service person sent to work on the equipment.

Note: Most provinces have adopted environmental protection legislation to reduce or eliminate the release of Ozone Depleting Substances (ODS). This legislation requires persons working with air conditioning refrigerant to take a one-day information session regarding the regulations. A certificate is issued upon completion of the session. This certification, although necessary, should not be confused with the trade Certification of Qualification.

We recommend you contact a qualified heating and air conditioning contractor to analyze your requirements. To locate a qualified complying contractor search HRAI's Contractor Locator.

AIR CONDITIONING SERVICE
Question:
My air conditioner has not been cooling my house properly and will not cool the house any lower than 82 °F. This started last summer so this spring I had a service company come and look at the unit. They said it was low on refrigerant, added some more and charged me $xxx. Two months later, it was doing the same thing, so I called them again and this time they said I needed a new unit that would cost me $xxxx. The air conditioner is only 6 years old and I don't feel I should have to buy a new unit. Can you tell me how long an air conditioner should last?

Reply:
The industry estimates that the life expectancy of residential air conditioning systems is between 12 to 15 years depending on usage, environmental conditions, etc. Air conditioning systems, of course, can fail before this but the most expensive component, the compressor, is warranted by most manufacturers for up to 10 years.

The fact that the refrigerant was low means that there is a leak somewhere in the air conditioning system. There are specific environmental regulations in all the provinces of Canada that prohibit the adding of refrigerant before removing the remaining refrigerant, finding the leak and repairing the leak. If this procedure was not done, the company and service person adding the refrigerant are breaking the law.

For more information on the qualifications required by a person to service, maintain or install air conditioning equipment please refer to the previous response entitled "Air Conditioning Contractor Qualifications".

To locate a qualified contractor that services your area search HRAI's Contractor Locator.