The Importance of Duct Sealing

In my last article I wrote how extremely important it is to properly air seal and insulate our homes.  This is because the more heated or cooled air that STAYS in your home, the less it costs you.  In this month's article, I'll go more in depth into why your duct system is just as important.

 

Duct systems distribute heated and cooled air throughout our homes. However, the vast majority of the homes I do energy audits for have the ductwork located outside the building envelope, typically in the attic, basement or crawl space.  The mechanical heating and cooling system in a home is similar to the circulatory system in our bodies.  The air conditioner, heat pump, and/or furnace is like the heart pumping warm or cool air to the air handler, which acts like a set of lungs pushing the air in and pulling it out of our home.  The ducts themselves are therefore much like veins, circulating the air to various parts of your home where it is needed.

 

From an energy conservation standpoint the home’s duct system is probably as important as the circulatory system in our bodies. This is because if the duct system has holes in it, some of the air you pay to heat or cool is escaping into the environment and not into your home.  Keeping it sealed tightly, working properly and adequately filtered will save you money in heating, cooling and repair costs.

The most efficient homes being built today are incorporating these guidelines. Many builders have begun to place the duct system in the “conditioned” space of the home, inside the building envelope. As a result, if leakage over time occurs, the conditioned air is leaked into the home rather than into the area outside. Some of our clients have actually retrofitted their attic space or basement to close off the ventilation and bring the ductwork into the conditioned space. This can be cost effective in the sense that you might not need to replace your whole duct system, even if you have some leaks. Figuring this out can potentially save you a large amount of money.  Determining exactly which measure makes the most sense (DOLLARS and sense!) is where a good energy auditor comes in. Spending just a few hundred dollars could possibly save you thousands.

Our Basic Energy Audit can tell you which of the two most important energy savingmeasures should be addressed first, air sealing or duct sealing.  During our Basic Energy Audit we measure your home’s air infiltration with a blower door test to determine if air sealing is the top priority. While that test is being done, we will test your home’s supply vents with a procedure known as pressure pan testing to determine approximately how leaky is your duct work.  Should the results of pressure pan testing show extensive duct leakage, we can switch gears and do the Comprehensive Duct System Evaluation instead of going forward with the Basic Energy Audit. The Comprehensive Duct System Evaluation determines exactly where the leaks in your duct system are occurring and whether your heating and cooling system is adequately sized and functioning properly. Our experience will determine immediately whether the basic audit or the duct evaluation would be the better choice, prioritizing your efforts and saving you money. Either of these tests is only $300.

If you want to go even further, our Comprehensive Energy Audit offers much more detail. It which includes a guideline for a making your home as energy efficient as possible. It tells you exactly which home improvements give you the fastest and greatest return on your investment. It provides you with results from both sets of tests included in the Basic Energy Audit, but also gives a list of priorities based on the results. These priorities will be ranked by how soon each home improvement will pay for itself through energy savings, giving you a scientifically based approach to saving energy. 

Using less energy not only saves you money. It also means your family will have a smaller carbon footprint and the less carbon based fuel we use, the better.