GIMME SHELTER- Cool down! Tips for proper a/c installation

Jerry Kidd
Beck Cohen


Q: I just moved into an older home without air conditioning. I'd like to think I could survive without it, but Charlottesville's notorious summer heat and humidity are already more than I can stand! What do I need to know about having central a/c?

A: Other than keeping you comfortable, central a/c will dehumidify your home, making it a healthier environment for you and your furnishings. If you are going to have a system installed this summer, find a company that doesn't charge extra for installation during their busiest season.

The cost and time required for installation vary widely, so take advantage of free estimates offered by most companies. Generally, though, a new system will constitute a significant investment and take at least a few days, so use a reputable company that offers a good warranty plan. 

There are two basic types of central a/c systems: traditional ducted and ductless (also called "mini-split"). Both types are split systems, meaning they have both an outdoor and an indoor unit. If you're looking to cool an entire home, you want to go with a traditional system, but ductless systems, which are used widely in Europe, are gaining popularity here for cooling smaller spaces. For example, a ductless system might the best choice if you want to cool a studio apartment or a room that's detached from the main house, like a garage loft.

Especially in an older home, keep the following few things in mind in order to run your system at maximum efficiency and avoid being bankrupted by summer utility bills.

Windows are the largest source of heat gain in most homes, especially if yours are single-pane. Leave your storm windows on and draw your blinds or shades during the day to reduce heat gain. Turn the thermostat up whenever windows are open.

 Inadequate insulation is the next biggest source of thermal inefficiency: the more insulation in your walls and attic, the better. If you just can't seem to keep the house cool, you may need to consider having it re-insulated. 

I recommend spending a little extra money to have your a/c hooked up to a programmable thermostat. This will allow you to set the system to automatically scale back whenever you're away, but have the home cool by the time you return. If you don't have a programmable thermostat, let the system run continuously through the day. Turning it on and off daily can overwork the system, since it has to work extra hard to make up for the heat gained while it was off.

Another common source of a/c inefficiency is an oversized system. If you install a system that's too big for your home, it will "short cycle." That is, it will cool the house quickly, but then turn off before a smaller unit would, thereby removing less latent heat and humidity.

Proper maintenance of your system is very important to keep it running efficiently for a long time. Clean or replace filters regularly, especially in a new system, because that will keep the whole system clean. Before the hot season begins, clean your condensate drain, which is where the water that your system removes from air goes. The drain will be on your indoor unit, and a company technician can teach you how to properly maintain it. I also recommend having your system serviced annually by professionals; the small price will be worth the return in increased lifespan and prevention of nasty leaks or other problems.