Ductwork - Duct Leakage TestingDuct Leakage and Sealing a Leaky Air Duct System
Don’t Force Your HVAC System to Run in Place
Gaps in your ductwork lower your HVAC systems
energy efficiency.
Let’s take a closer look: Your system turns on to keep your home comfortable, and the fan kicks on to start circulating air. As soon as the fan gets up to speed, your leaky return ducts start to suck in air from your hot attic or cold basement or crawl space. Instead of dealing with air returning from your house at indoor temperatures, your system encounters unconditioned air that’s much hotter or colder. Your furnace or air conditioner has to work extra hard to make this air the right temperature.
Okay that’s bad, but that’s only the half of it. Now you’ve got air that’s not quite “cold enough” or “warm enough” traveling down your supply duct system, and your leaky supply ducts let some of this air (which you’ve already overpaid to heat or cool) leak out instead of delivering it to your home. As a result, your system needs to be larger and run longer and you have uncontrolled “bad air” leaking into your living space. Your allergies flair up, and your house is dirty and dusty even a day or two after cleaning. Okay, so ducts are really important… yeah, really important.
Balancing Air Duct Supply and Return
What Goes In (must) = What Goes Out. Efficient HVAC performance depends on balanced air flow. The air volume your system returns from your house should equal the air volume your system supplies to it. If one is greater than the other, there is an air pressure imbalance. Negative pressure in a room can act like a vacuum, pulling air into the room from outside or from “bad” sources like a crawl space or attic. Drafty or uncomfortable rooms may be the result of imbalanced airflows.
Diagnose Duct Problems, Then Solve Them
It takes the right tools and good diagnostic skills to detect duct leakage and other duct problems. When Dr. Energy Saver tests your ductwork system, you will see instantly how you are loosing energy and wasting money. You’ll also find out if your ductwork system is causing pressure imbalances that can encourage outside air to leak into your house.Sound Sealing Strategies - Caulk it, Foam it, Seal it!
What follows after leak detection
is leak sealing.
Only a Quack Would Use “Duck Tape” on Ductwork
Duct tape has thousands of uses, but it shouldn’t be used on ductwork. This tape was originally developed during World War II to keep moisture out of ammunition cases. Servicemen appreciated the tape’s waterproof qualities and the fact that the cloth backing was made from cotton duck cloth, so the name “duck tape” was coined. After the war, duck tape became “duct tape” when contractors began using it to seal ductwork. But time has taught us that duct tape dries out and disintegrates when used on ductwork. Its sealing effectiveness doesn’t last very long. So, the moral of the story is that duct tape is handy to have around; just don’t use it for sealing leaky ducts.Air Ducts Need Insulation Too!
Without adequate insulation, the conditioned air that you paid to heat or cool travels through your ductwork with little or no protection against extreme air temperatures. Imagine a sheet metal duct system in a sweltering attic on a hot summer day. How much do you think cool conditioned air might warm up as it flows through hot ducts? Or, how about heated air running through ducts in a freezing crawlspace? How much do you think this heated air will cool down as it passes through freezing ductwork? These energy losses can really add up fast, and they have a negative effect on comfort as well as energy efficiency.Adding insulation can help to reduce energy losses in duct runs. Dr. Energy Saver will know the best type of insulation, as well as the proper insulation levels to use to make your ductwork and home more energy efficient.
