Does Your House "Suck"? Ducting for your AC

>Ken: Ducting, what a truly boring subject. This could be wasting you lots of money and energy by cooling or heating your attic or crawlspace (wherever your ducting is located). Ducts are not the birds we like to eat at holiday time, rather they are those metal or plastic tubes that move the air to and from your air conditioner and the rooms in your home. I spent the better part of 2 years testing ducts for tightness in the Fresno, Ca. area, and found that the average home's ducts leaked about 30%-50% of your conditioned air into the attic or crawlspace. While this obviously costs you money, it can also be dangerous to your health.

Return air leakage is the worst culprit for costing you money. It is sucking in attic air (assuming the ducts are up there) at possibly 130 or 140 degrees Fahrenheit. When the AC conditions your air, it takes partially conditioned air from your home and cools it by about 20 degrees. You can see that if it is pulling in 140 degree air from your attic and mixing it with what you have inside your home that what it delivers back into your home won't be anywhere near as cool as you want.

>Jason: An air conditioner is designed to deliver exactly the same amount of air as it pulls out. When you send air into your attic, you are preventing the air from returning to your home. Since the air came out of your living space, you create a vacuum, sucking air in from wither the outside or from your attic. This air will not be nicely filtered and usually has lots of contaminants. The air in your house can be up to 100 times worse than the outside. So if your ducts leak, you are conditioning your attic and you are poisoning your air! So how do you know if your ducts leak? Its a simple procedure that most HVAC contractors can do called a duct test.

>Ken: Your ducting should not be leaking any more than about 15%, and should be much less (about 5%) if the home is less than 5 years old. Many HVAC contractors will do a duct test for a very low cost. Duct seals may receive a rebate from your local utility. Let us know who your utility is, and we can research for you what is available.

>Jason: To wrap this up, one easy way to determine if your ducts are leaking is to look for dark lines along the edges of carpet or around your supply vents. This is an indicator that you are sucking dirty air in from the outside. You can also turn your system on and unlatch an outside door. If the door pulls inward, you have negative pressure on the inside of your home, which means you have leaky ducts. So until next time, dont let your house "suck" and be energy smart!