Your Old Ducts are Costing You Money!!
If your home is built before 1980 and you have high bills or comfort issues this is where to start. Look below and you will understand that YES, half the cold air you are buying is ending up in the attic.
If your home has METAL DUCTS this is the place to start. When these homes were built (before 1980) energy efficiency was not even on the list of considerations. I see this everyday and without fail, major comfort issues are always related to ductwork or the mechanical system.
If your home has old GREY flex ducts these probably need to be replaced.
This was the first stab at flexible ducts. They were a failure. They would eventually disintegrate from exposure to UV. Now most ducts use the “silver” or “shiny” flex ducts.
How is Duct Leakage Tested?
There is process to test the air leakage of ducts called a “duct blaster test”. On new highly efficient homes the target is about 2-4% leakage. On “average” homes with flex duct (the stuff that looks like slinky’s) it is 20% or more and on homes with old metal rigid duct they often cannot even get a reading, meaning the leakage is over 40-50%. In California they are requiring duct sealing certification with the replacment of a new AC system. Read the Requirements HERE Also, here are some good videos produced by the California Energy Commission describing the benefits of reducing air duct leakage.
Where Does The Duct Leakage Come From?
Duct leakage is due to several factors: (Remember, prior to 1980 energy was cheap, plentiful and nobody really cared about their electric bill). The main cause is that the connections were never sealed to start. Also, damage (crushed or separated pipes from 3rd parties doing work in the attic) or separation from vibration over the years. Plus, they usually have about a 2 R-value of insulation resulting in a significant amount of heat gain as the air travels down the duct to the room.
What Does All This Mean?
What this means is that if you have metal or grey flex ducts, then you are either blowing half the cold air into the attic or could be pulling hot attic air into your return ducts.
Before you consider other options, the duct should be address first. Often customers fix the ducts first, and worry about the insulation later. It is pretty typical for the air coming out of the vents to drop 10-15 degrees after the ducts are replaced due to the leak reduction and added insulation on the ducts. I’ve seen so many times, I can practically predict it every time. Remember Duct SEALING and Duct CLEANING are not the same thing. Don’t bother with duct cleaning, it won’t help with efficiency.
Reduce Your Electric Usage 50% or More!
When the ducts are fixed AND insulation is added the usage often drops 30-50% or more, all rooms are more comfortable, and dust is greatly reduced after eliminating the negative pressure from the duct leaks (which constantly draws air in through all cracks, doors windows, etc.). Remember the air being pulled in is hot and HUMID. Humidity adds extra heat load into the house. Because of the high humidity, it can be 72 degrees and still feel warm. If the humidity is low, then It can be warmer and be more comfortable.
Look For Yourself
I’ve included some pictures below to illustrate just what’s going on BEHIND the insulation once you pull it back. Most people think the insulation keeps the air in, this is NOT true. Notice the discoloration of the insulation. This is caused by the insulation acting like a filter over the years from the air leaking into or out of the ducts. I’ve heard it a hundred times that “I had the ducts checked and the guy said they were fine”. Then, when you pull the insulation back you see what is included in the these pictures. It’s like trying to stop a leak with a rag. It just won’t work. Some AC contractors would rather sell you a new piece of equipment rather than fix the real problem which is the ducts.
Tell a friend or neighbor. Homes with metal ducts (usually built before 1980) are notorious for having high bills and being difficult to keep comfortable. People search desperately for something that will make a difference, but until the ducts are fixed nothing will really have a big impact. Once the realize HALF the cold air they are buying is not ending up in their home, then it all makes sense.
Advantages of tight air ducts
Energy / Money Savings
More even room temperatures and comfort throughout the home