Air Conditioning FAQ
Frequently Asked Questions

  1. How do I keep my cooling costs to a minimum?
  2. How does an air conditioner work?
  3. Is central, attic based, or ductless air conditioning better than window units?
  4. Should I augment my central air conditioning with other air conditioners?
  5. What is the average life of a central or attic pak air conditioning system?
  6. What should I do in advance to make sure my cooling system will work efficiently this summer?
  7. If my cooling system is no longer cooling properly, what is the most likely problem?
  8. Can homeowners repair their own cooling systems?
  9. When do I know when it’s time to replace my system?
  10. Is it better to let an existing system wear out before replacing it, or replacing it at some point before it wears out?
  11. How do I go about shopping for a new system?
  12. Do I need to replace both my outdoor condensing unit (which includes the compressor) and the indoor coil on my central or attic pak system at the same time?
  13. What is the best kind of control for a new system??
  14. How can I get a system that will have minimum operational costs?
  15. How can a homeowner tell if a contractor’s price is fair?
  16. How easy is it to install a cooling system in an older home?
  17. If I’m buying a house, how can I make sure that the cooling system is in good working order?
  18. How does the efficiency rating work for air conditioners?
  19. What are the advantages of buying a system with a high SEER?
  20. How can I determine the SEER of my present equipment?
  21. How can I find the savings of higher SEER equipment compared to lower SEER equipment?
  22. What are typical savings to expect from higher SEER levels?
  23. What percentage of my utility bill is caused by cooling?
  24. How often should I change the air filter in my system?
  25. Will I get cleaner air by shutting up my house and running my central air conditioner or heating system, or by opening up my house as much as possible to let in fresh air?
  26. How, and how often, should I clean my air conditioning registers and ducts?
  27. Should my home be humidified?
  28. Is there any advantage to letting the system’s fan run all the time (the ‘on’ setting on the thermostat) instead of periodically (the ‘auto’ or ‘automatic’ setting on the thermostat?
  29. In hot weather, should I turn my thermostat up when I leave for work in the morning?
  30. Can my cooling or heating system reduce or eliminate radon or other ‘sick building’ problems?
  31. Is there any relationship between my home air conditioning system and chlorofluorocarbon (CFC) refrigerants and the ozone layer?
  32. Is there anything dangerous about the refrigerant in my cooling system?

1.

How do I keep my cooling costs to a minimum?
  • Caulk, weather-strip, and insulate (especially the attic) to close air gaps
  • Plan hot work (washing and drying clothes, baking, cooking) for cooler morning and evening hours
  • Pull drapes and shades over windows facing the sun
  • Keep windows and doors closed when the air conditioning is on
  • Use a thermostat control to automatically increases or decrease home temperatures for daytime / night time differences to save money
  • Set thermostat control at highest comfortable level – each degree raised reduces energy consumption by 3-4 percent
  • Clean or replace air filters regularly
  • With a new system, consider a service contract for a specified period of time
  • Keep the outside unit free of leaves or other airflow obstructions
  • Have the air conditioning unit cleaned each spring with annual AC service from Belyea

2.

How does an air conditioner work?

An air conditioner transfers heat from the inside of a house / building, where it is not wanted, to the outside. Refrigerant in the system absorbs the excess heat and is pumped through a closed system of piping to an outside coil. A fan blows outside air over the hot coil, transferring heat from the refrigerant to the outdoor air. Because the heat is removed from the indoor air, the indoor area is cooled.

3.

Is central, attic based, or ductless air conditioning better than window units?

This depends largely on individual circumstances: for example, how large is the area to be cooled, how large is the family, what temperatures are required, how well is the house insulated, where is the house located etc. Central and attic based systems require internal ducting. Ductless air conditioning requires wall space. In most circumstances, if more than three rooms need cooling, it is best to consider a central or attic based system. By examining your house our sales team will be able to advise you about the best solution for your house.

4.

Should I augment my central air conditioning with other air conditioners?

If you need to use other air conditioners with a central system, your system is probably undersized or the air distribution system is imbalanced. Typically, a central system does not have a big enough fan to push dense cold air up beyond the second floor – in this circumstance a ductless system may be required. Ductless air conditioners can also be installed in sunrooms or other additions that may lack air ducts.

5.

What is the average life of a central or attic pak air conditioning system?

This depends on how much the system is used and how regularly it is checked or serviced. Generally, the average life of cooling units built in the 1970s and 1980s is about 15 years, but individual units may vary and last longer, depending on use and how well they are maintained. Newer cooling units are expected to last much longer.

6.

What should I do in advance to make sure my cooling system will work efficiently this summer?

The main thing is to have the system checked each year before the peak-cooling season by a qualified AC service technician. Then, remember to keep the air filter clean and the outdoor unit free of leaves and debris.

7.

If my cooling system is no longer cooling properly, what is the most likely problem?

It could be as simple as replacing a fuse, resetting a circuit breaker or checking to see if the thermostat is set properly. If an electrical problem isn’t the cause, the refrigerant may be low if the system still runs but does not cool properly. This can be corrected by having a certified technician add the necessary refrigerant. If the problem involves any major part, such as the compressor, you would hear strange noises similar to those of any mechanical equipment not running properly, or the unit might not run at all. Contact your installer for air conditioning repair.

8.

Can homeowners repair their own cooling systems?

In most cases, definitely not. Cooling systems are more complicated to service and usually require expert attention in order to comply with federal regulations, such as the Clean Air Act that prohibits releasing refrigerants into the atmosphere. Contact your installer or licensed service technician at the first sign of trouble for professional AC repair.

9.

When do I know when it’s time to replace my system?

When the system starts giving you more problems than seem cost-effective to fix, particularly when major components start making unusual noises or otherwise indicating need for a service call. Talk to your contractor for their recommendation. Replacing a compressor is somewhat less expensive than replacing the entire unit, but new units may give you greater efficiency and lower operating costs in the long run.

10.

Is it better to let an existing system wear out before replacing it, or replacing it at some point before it wears out?

Because newer equipment usually is more energy efficient than older cooling systems, you might actually save money by replacing your old system before it completely wears out. Contact your contractor and ask for an estimate. In some cases, the money you save in reduced utility costs might pay back your purchase price of a new system years earlier than you might think.

11.

How do I go about shopping for a new system?

Ask friends and neighbours about the types of systems they have, how much they cost, how long they’ve had them, and how satisfied they are with them. Then ask for recommendations as to brands and local contractors, or ask several different contractors to take a look at your home, evaluate your overall comfort needs, and recommend the best system for you. Look at all indoor climate control options – the entire spectrum of heating, cooling, air filtration and humidification equipment. Learn more about the air conditioning installation from Belyea Bros.

12.

Do I need to replace both my outdoor condensing unit (which includes the compressor) and the indoor coil on my central or attic pak system at the same time?

Overwhelmingly, yes. Matching a new condensing unit with a new coil is the only reliable way to be certain you are going to get the rated efficiency of the new equipment. Matching a new, high SEER (seasonal energy efficiency ratio) condensing unit with an old indoor coil probably would not result in optimum efficiency.

13.

What is the best kind of control system for a new system?

If you want flexibility to program your temperature changes, a computerized thermostat will probably be best. A manually operated system will require you to change the temperature setting whenever you want to change the temperature.

14.

How can I get a system that will have minimum operational costs?

Manufacturers publish equipment efficiency ratings that are available to your contractor. ARI (Air Conditioning and Refrigeration Institute) also publishes directories indicating various energy efficiency ratings of specific equipment. It is important that a contractor install a unit that has just the right capacity to cool your home. Units with excess capacity will cycle on and off and work less efficiently, thus increasing your operating costs.

15.

How can a homeowner tell if a contractor’s price is fair?

Compare the bids of three reputable contractors. Check with your neighbours to see which company they recommend. If a price is too good to be true it usually is. You want to be able to contact the contractor if you need help or additional service. Ask how long a company has been in business – chances are if they’ve been around for a while they do good work. Remember 25 years experience does not mean a business has been around for 25 years.

16.

How easy is it to install a cooling system in an older home?

It is often fairly simple to design a cooling system for an older home. If there is existing ductwork connected to your furnace a central system may be added. For homes that have hot water heating or electric heating an attic pak or ductless split system may be the answer. An important consideration is how well the older home is sealed and insulated. Belyea Bros. is an expert in cooling older Toronto homes. Learn more.

17.

If I’m buying a house, how can I make sure that the cooling system is in good working order?

Just turn on the system and listen for unusual sounds while feeling how cool the air is and how strong the airflow is from the vents. Don’t just listen inside the house – go outside and listen to the condensing unit, too. This personal inspection is a good indicator, but like buying a car, the best way is to then hire an expert (the contractor) to come out and inspect the system. It won’t cost much, and it could save you lots of money in unanticipated repairs.

18.

How does the efficiency rating work for air conditioners?

All cooling systems are rated by the seasonal energy efficiency ratio (SEER). Many older systems now in use have SEERs of 6 or below. By 1994 the average SEER for all units shipped in North America improved to 13 SEER. The higher the rating, the more efficient the system.

19.

What are the advantages of buying a system with a high SEER?

You will use less energy to cool your house, resulting in lower electric bills. Sometimes the savings are enough to partially or fully offset the cost of the new equipment within a few years. In all cases, it’s an individual calculation that the homeowner should figure out with the contractor of choice.

20.

How can I determine the SEER of my present equipment?

There are three main ways to determine the SEER of equipment:

  1. Find the model numbers of your present equipment (the outdoor condenser / compressor unit and the indoor evaporator coil unit) and check them with local contractors who handle your brand
  2. Estimate the SEER based on the average SEER of units produced when your unit was installed
  3. Check the energy efficiency label on your outdoor condenser / compressor unit if you have equipment produced after late 1988

In the first method, contractors can then consult manufacturer data to determine the SEER rating. In the second method, for air conditioners produced in 1981, the first year SEER criteria were used, the average rating was 7.51. By 1987, SEERs reached 8.97. By 1994, ratings increased to 10.61 for air conditioners. In the third method, residential air conditioners manufactured after 1988 are required to have labels containing energy efficiency information. For each system, the label will be on the outdoor condenser / compressor unit, and will reflect the SEER achieved by matching the outdoor unit and the indoor evaporator coil unit.

21.

How can I find the savings of higher SEER equipment compared to lower SEER equipment?

You’ll need to talk with a local contractor to verify what size cooling equipment you now have and what you actually need, then determine the normal cooling load hours for your area, and find your electric rate cost. The formula is as follows:

Capacity (Btuh) x Cooling Load Hours x Electric rate = Annual Operating Cost
SEER 1000

For example, if a home requires a unit with a capacity of 36,000 Btuhs (British thermal units per hour), is located where the cooling load is 1500 hours and the electric rate is 8 cents per kilowatt hour, here is the calculation for a system with a SEER of 10:

36,000 x 1500 x 0.08 = $432 per year
10 1000

The same calculation with a SEER of 12 reveals an annual operating cost of $360 or $72 less per season ( a 17% saving).

22.

What are typical savings to expect from higher SEER levels?

This is an estimate of representative operational costs of three SEER levels for a 2000 square foot split level house (actual costs may vary greatly depending on individual circumstances):

SEER 7 SEER 9 SEER 11
$301 $234 $192

23.

What percentage of my utility bill is caused by cooling?

It can be surprisingly small on an annual basis, but it depends on how much you use your air conditioning, how efficient your equipment is, and how much you conserve energy by actions ranging from insulating your home to keeping doors and windows closed when the system is operating. Your local electrical company is the best source for specifics in your area.

24.

How often should I change the air filter in my system?

Check it at least every month during peak use, and replace it when it looks dirty enough to significantly impair the airflow through it. Some filters, such as media filters or electronic air cleaners, are washable; others are disposable and must be replaced.

25.

Will I get cleaner air by shutting up my house and running my central air conditioner or heating system, or by opening up my house as much as possible to let in fresh air?

As you might suspect, this depends primarily on the quality of air outside your home, the quality of air inside your home, and your home’s indoor comfort equipment. Indoor air quality varies greatly from building to building. Factors may include everything from emissions by the materials used in your home’s construction to the kind of cleaning products you use for personal and household needs, to possibly even radon from the ground or water in some areas. Optimum air quality is a matter of personal preference, as is deciding when it is best to air out the home, and when it is best to rely primarily on the cooling / heating equipment. Research on indoor air quality is gaining momentum, but it may be years before comprehensive analysis of the spectrum of variables affecting indoor air quality is widely available to households nationwide. Using a high efficiency air cleaner or HEPA filter on the central cooling / heating system remains one of the best ways to help maintain a clean indoor environment. High efficiency air cleaners can remove particles smaller than the eye can see.

26.

How, and how often, should I clean my air conditioning registers and ducts?

Duct outlets and registers should be cleaned as part of your regular home cleaning routine. It’s the filters in the system and, to a lesser degree, the grilles and registers at the duct outlets that collect the most dust, and therefore need changing or cleaning. Ducts don’t usually require cleaning, especially if filters are kept clean. You can occasionally check ducts by removing a few registers and inspecting the ducts from the inside with a flashlight (be sure to look at the return air ducts). If the insides of ducts need cleaning, some contractors provide this service.

27.

Should my home be humidified?

That depends largely on your climate and personal needs. Humidification is definitely helpful in many homes and businesses. Particularly during cold weather, insufficient moisture in the air often is responsible for such assorted problems as stuffy noses, sore throats, even more dust than usual, cracks and dried-out joints in wood furniture, wilted plants, and static electricity that jolts hair, clothes and computer disks. Indoor relative humidity may fall to around 7 percent in the winter, much drier than even the 25 percent relative humidity of the Sahara desert! Ideal indoor relative humidity is between 30 to 50 percent.

28.

Is there any advantage to letting the system’s fan run all the time (the ‘on’ setting on the thermostat) instead of periodically (the ‘auto’ or ‘automatic’ setting on the thermostat?

If you live in a very humid climate you may not want to run the fan continuously because this reduces dehumidification, however, there are also advantages. Continuously circulating the air keeps the temperature more even throughout the house by alleviating temperature stratification. It keeps air circulating through the comfort system’s air filter, which, depending on filter type and efficiency, can keep the home cleaner and the air fresher to breathe. When the fan is operating continuously, the compressor continues to periodically cycle on and off automatically to cool and dehumidify your home just as it does on the ‘auto’ setting.

29.

In hot weather, should I turn my thermostat up when I leave for work in the morning?

If your house is going to be empty for more than four hours, it’s a good idea to turn your thermostat up to about 82 degrees or so instead of the usual 78 degrees recommended. Keep the house closed to minimize heat build-up. When you come home, don’t set the thermostat any lower than the temperature you actually want. Your cooling system won’t cool any faster by plunging the temperature on the thermostat and might easily waste money by cooling your home more than needed.

30.

Can my cooling or heating system reduce or eliminate radon or other ‘sick building’ problems?

As a gas emanation primarily from soil or rocks, radon can be detected and measured by relatively inexpensive monitors that are becoming increasingly available to the general public. Considerable research is being done on measures to control radon and its health effects as typically found in indoor building environments both residential and commercial. At present, most conventional home central cooling and heating systems appear to have little, if any, effect on radon. ‘Sick building’ essentially refers to some buildings that may have excessive concentrations of pollutants. Such pollutants may range from cigarette smoke to chemical emanations from materials used in furniture or building construction, to biological contaminants such as fungi (molds and mildew) and bacteria growing in areas where moisture may collect and stagnate. This may occur in such diverse locations as improperly maintained or damaged ceiling tiles, dishwashers, carpeting and air conditioning drain pans. Most problems allegedly have occurred in commercial building. Cleanliness and adequate ventilation are major considerations. If you believe you may have a problem, you should seek the advice of a qualified contractor. For more information about radon and ‘sick building’ problems, contact your local government environmental office.

31.

Is there any relationship between my home air conditioning system and chlorofluorocarbon (CFC) refrigerants and the ozone layer?

An international protocol limits future worldwide production and consumption of the fully halogenated CFCs 11, 12, 113, 114 and 115. Virtually all of the refrigerant used in residential and light commercial cooling systems is called HCFC (or R) 22, which has some ozone depletion potential, but only 1/20 that of CFCs. This is because HCFC-22 breaks down fairly rapidly when released into the lower atmosphere, and most of it never reaches the ozone layer at high altitudes. HCFC-22 will be phased out of production for use in new equipment by the year 2009 and for servicing existing equipment by 2020. After the phase-out, there will still be refrigerant available for servicing existing equipment. Manufacturers are beginning to produce units that use alternative refrigerants such as R-410 or Puron. Consumers can, even with existing refrigerants, both enjoy their air conditioning and help protect the environment by following a few simple guidelines:

  1. A ductless, central, or attic pak cooling system is a closed system and will not release refrigerant into the atmosphere as long as it is properly installed and maintained. Have your system checked by a service person once a year before the cooling season. Make sure the technician checks for refrigerant leaks.
  2. After July 1, 1992, intentional venting of refrigerant is against the law. All refrigerant from units must be recovered.
  3. Only patronize service companies that have the proper equipment to do so.

32.

Is there anything dangerous about the refrigerant in my cooling system?

The refrigerant (HCFC-22) in residential and light commercial air conditioning systems is nontoxic, nonflammable, odourless, and sealed within the system. Nonetheless, like any substance, it can be abused. You should be aware that some people have died from deliberately inhaling or ‘sniffing’ pure gas (e.g. after buying and ‘sniffing’ cans of refrigerant like those used to recharge automobile air conditioners). Inhaling such concentrated refrigerant vapors can cause cardiac irregularities and cardiac arrest. Although a large release of refrigerant vapour could displace oxygen available for breathing and cause suffocation, this is virtually impossible with residential systems because of the relatively small amount of refrigerant used (e.g. 24,000 to 36,000 Btuh (2-3 tons)) used in those systems.

This document is published by the Air Conditioning and Refrigeration Institute.