If you live in an area where heat is a dominating factor, you are likely to have central air conditioning. Naturally, you want your air conditioning to run as efficiently as possible.
Probably the single biggest cause of poor A/C performance is leaky ducts. Ducts are kind of like pipes – they move air through them and deliver it at the end. We notice when our water pipes leak because we see the damage immediately, but we rarely see the effects of leaky ducts directly; rather it sneaks up on us over a long period of time, and many people never figure it out.
When ducts leak, they let cool air out into whatever space they are in, often the attic, which, in case you haven’t noticed, can get pretty hot in the summer. Ducts need to be sealed at all the metal-to-metal and metal-to-flex connections – not at the insulation. Have someone pull back all the insulation and put a nice thick layer of goopy mastic at all the joints, then replace the insulation. Don’t use duct tape. It won’t work, and the metal tape designed for ducts doesn’t do a whole lot better.
However, you do want to make sure all of your ducts are well insulated to maximize cool air into your home. Make sure you have the right filter for your central air. If you use a filter that does a super job of filtering the air coming in, the downside is it keeps too much air out and your cooling coils can freeze up.
Source: www.networx.com; Carl Seville; June 7, 2012.