One of the most expensive purchases you will ever make for your home is an air conditioner – whether you are replacing existing equipment or choosing a heating and air conditioning system for a new home.
Once your AC system is up and running, it could be a decade or more before you replace it. Since you will be living with it for a long time, you want to choose wisely.
If done correctly, a new air-conditioner will result in more comfort year-round, lower energy bills and better air quality — particularly because of recent improvements in cooling-equipment technology and installation procedures.
Here are basic points to remember during the process:
1. Pick a trusted contractor. Unless you have worked in the HVAC field, you cannot expect to completely understand all the details in air-conditioning; no homeowner can. This creates a situation where you might be taken advantage of, and you need to proceed carefully.
Do pick a contractor like Air Quality Control, based on recommendations from friends or neighbors or a reputable referral network. Don’t choose one after talking to a telemarketer or because someone came to your door to make a solicitation. Be suspicious of mailings offering cut-rate prices.
Ask references: Did the contractor do what was promised? Has he or she returned to fix problems that came up after installation? How do the customers like the air conditioner they chose? What impact have they seen on their utility bills?
2. Take the contractor’s advice. Researching online or asking others who have purchased air-conditioners is always good. But be cautious about insisting on a specific brand or size of air conditioner, especially when recommended by someone living in another state.
Once you choose an installer you trust, ask for suggestions. The contractor may know about options that suit your home better than what you had in mind. A good contractor also knows which manufacturers give the best warranty.
3. Buy an air conditioner that fits your home. Make sure your contractor does research about your house, the microclimate you live in, and the condition and placement of your air ducts. That way, he or she can determine how much air conditioning you need and whether you need to repair or realign ducts to improve your cooling efficiency.
Be very, very cautious. If a salesperson makes a proposal without visiting your attic to look at your furnace and air handler or without checking the air condition in the yard or on the roof, he or she is not doing the necessary homework.
4. Bigger is not always better with air-conditioning. AC experts tell us that for years we have “over-tonned” houses in Arizona by installing air-conditioners too large for the size of the house.
A quick explanation starts with a few definitions: The cooling power of air conditioners is often described as “tons of refrigeration.” A ton of refrigeration is roughly equal to the cooling power of one ton (2,000 pounds) of ice melting in 24 hours. Residential central air condition systems are usually from 1 to 5 tons in capacity.
The industry used to recommend installing 1 ton of refrigeration for every 400 square feet of floor space in your home. But times have changed, and energy efficiency has improved. You can probably go with 20 percent less tonnage than before. You can go down about half a ton in your air condition without even noticing it.
Be wary of contractors who recommend increasing tons because of warmer areas in your house. That cannot be solved by increasing the capacity of your air conditioner.
An oversize AC stops and starts more often; that costs more kilowatt hours and could lead to mechanical breakdowns. An oversize air conditioner do not run long enough to dehumidify the air. A smaller air conditioner unit will run longer and perform more efficiently.
Your contractor should perform a heat-load calculation before deciding what size air conditioner you need. That calculation should consider the size, shape and orientation of your house, insulation, window area, air infiltration, climate, number of residents in the house and their comfort preferences.
– Rosie Romero