Taking a little time up front to learn more about air conditioning and heating will save you time and money when you choose a local contractor and system. Plus, the air conditioning and heating system you get will most likely deliver the indoor comfort and lower bills you need. This page gives an overview of how to buy a new A/C and heating system. To the right of this page, you will find links to pages with contact information on local air conditioning and heating companies.
(1) When preparing to buy a new A/C and heating system, two of the most important decisions you need to make are (1) selecting the right local company to size the equipment, design the system and control the quality of the installation, and (2) choosing the equipment with the efficiency rating and features to fit the specifics of your situation.
HVAC contractors sometimes offer several brands of equipment. Within the major HVAC manufacturers, equipment brand will not likely impact your satisfaction nearly as much as the right contractor and energy efficiency. However, since some owners have experience or preferences on brands of equipment we provide a handy worksheet to help organize and compare price quotes based on brand and main features.
(2) Getting the correct size of air conditioner and furnace
Regarding size of air conditioning and heating equipment, the goal should be to get the optimum size and features for your climate and situation–bigger is not better.
The three main areas your HVAC contractor considers in their load calculation include: the amount of heating and cooling needed in your climate, the amount of area you have to heat and cool, and the condition of the “envelope” or part of your home or building that interfaces with the outside air. Within each of these categories, there are many factors that affect the load and equipment size.
HVAC contractors measure the size of A/C systems in tons. If you get a system with too low a tonnage rating, the system will work too hard and use too much electricity attempting to cool the air. Conversely, if you get a system with too much tonnage, the system will cycle on and off too quickly to “condition” the air properly. This results in “clammy” uncomfortable feeling cold rooms plus extra wear on certain parts of the system.
On the heating side, if the size of central heating system you buy is too large, you will pay more than necessary for the equipment. An oversize heating system cycles on and off too quickly, and causes extra wear on certain related parts. If a heating system is too small for the space, the room will take too long to heat up or have cold spots in it. In this case, running too long to try and keep up with the thermostat setting would likely cause extra wear on the heating equipment and waste energy.
(3) Pay attention to the efficiency ratings: SEER, AFUE, and HSPF/COE
and understand the relationship between higher up front costs and long-term savings through lower utility bills for air conditioning and heating. For central air conditioners, efficiency is rated in SEER. The heating industry uses a rating called the Annual Fuel Utilization Efficiency (AFUE) to measure the efficiency of converting gas into energy for heating. Heat pump efficiency gets expressed in a couple of ways, either HSPF or COE.
(4) When considering cutting edge equipment or new models with a lot of features
Ask how long the product has been sold and if you should anticipate any additional maintenance or repairs with the extra features. If you purchase a model with a lot of extra features, you should consider getting an extended parts and labor warranty along with the maintenance agreement that we always recommend. Generally, the extra features come together with the highest efficiency equipment. Examples include multi-stage equipment or fan speeds and electronics with many settings.
(5) Find out if there are any efficiency rebates or conservation incentives
available from your city or local power company or other third parties before you decide to make a major repair or buy a new system. Rebate programs often specify a certain minimum efficiency rating or energy conservation measures to be eligible. Your contractor should be aware of the rebates and able to participate. Check the links on the right side of the page for local resources in your city.
(6) When calling heating and air conditioning contractors, it will help to have the number of heated and cooled square feet in your home (this usually does not include the garage).
(7) If your A/C unit needs replacing before the furnace or central heating
You should get trusted advice from your contractor on how the new and old components would work together. Even though the new A/C and old heating components might physically be made to work, this does not necessarily make matching them your best choice. If you can afford it, replace both the air conditioning and heating components at the same time for more predictable results. The availability of rebates could also be a factor here.
(8) If you can plan ahead and get a new system purchases done during the non-peak season (before blazing summer days or the arctic fronts blow in) your HVAC work will be easier to schedule and you are more likely to receive off-peak season pricing.
(9) When negotiating a contract to buy a previously owned home, if your homebuyer’s inspection finds a problem with the air conditioner or furnace, you will probably want to call a HVAC contractor for an estimate for repair or replacement. Since you do not yet own the home, some HVAC companies will not want to give a free on-site cost estimate for replacing the system. If this happens, you might offer to pay for the on-site estimate on a new system, provided the company will take some or all the cost of the estimate off any new system you purchase within a reasonable on the length of time. To prevent confusion later, ask to have this arrangement written on your receipt when you pay for the estimate.
(10) Annual maintenance agreements are often a good value in air conditioning and heating.
To get off to a good start on maintaining your new system, we recommend you sign up for annual maintenance. HVAC companies offer these in several ways, but generally, you would want the A/C side checked in the spring and the heating side checked in the fall. In addition to preventing repair or safety problems and helping keep utility bills to a minimum, some companies offer associated discounts on repair parts or labor when they become necessary.