Photo by Belinda Hankins Miller.
This month’s topic on the Green Mom’s carnival is global warming being hosted over at Not Quite Crunchy Chicken. How many of you are freezing as much as I am? How many of you are tempted to crank that thermostat up until your toes are all warm and snuggly?
Stop right there. If you don’t show some love to your heating and cooling ducts, then your toes might be snuggly, but your wallet will be empty. According to Energy Star, a typical house loses 20% of the air movement through its duct system due to leaks, holes, and poorly connected ducts. So our systems run longer to meet the demand of our heating and cooling systems and our energy bills sore. Worse yet, the increase energy use causes more fossil fuel consumption at power plants which contributes to smog, acid rain, and global warming.
What I realized this fall as a volunteer in the energy exhibit area at Twin Maples, a renovated green historic Show House that most people had no ideas that their lack of attention to their ducts could be causing their increased energy bills each month.
The energy exhibit was created to enlighten the Show House guests how Twin Maples was renovated to make it more energy efficient and green. On display was a multitude of green products used in the house.
As guests would come in, I would go through my routine and explain why insulating your house and changing your old drafty window was important, have them “ooh and ahh” over the bamboo flooring, and show them all the different eco-flooring choices that could make their hearts sing. My last part of the routine was to point to the ceiling at those ugly silver exposed metal ducts in the basement.
I left this part of my routine for last because I believed that if they remembered anything I said during my routine, hopefully it was the last part about their ducts. In addition, wrapping and sealing the ducts is an inexpensive, but a crucible fix.
Mastic, Mastic, and Mastic
As they were looking at the most unappealing metal duct, I would start with the old money trick. “Do you realize that you could be losing a lot of money every month simply because your ducts are leaking?” (Now, I had their attention.) They would look at me with puzzled faces.
Then I would say, “ever wonder why you can feel cold air coming out of your ducts in the summer and heat in the winter in your basement, but you don’t have vents in your ducts?”
They would reply, “you are right,” and nod their heads in unison.
Then I would point to the rubbery, rough coating between the duct joints (where the ducts would meet) and tell them that this where most of your leakage comes from in your ducts. That ugly coating is duct mastic, which seals seams, joints and cracks in new and old heating and air conditioning ducts. Oikos has a wonderful article on how to apply mastic. Make sure you use a low or non-toxic brand. All of my ducts are sealed with AMF Safecoat’s DynoFlex . (To purchase any AMF Safecoat product, check here for the closet vendor.)
I would also warned them that ordinary duct tape is not sufficient to seal the seams. Again, I would see a round of heads shaking.
Why be Goldilocks in your house?
Next stop on the duct tour was the zone damper. Most people I spoke to had one zone systems and complained that one side of their house was too hot and the other side was too cold.
Basically, a zone damper shuts off one’s rooms heating and cooling needs when it reaches temperature. The other rooms continue to heat or cool until they reach the satisfied temperature. No more need to crank up the thermostat because one side of the house is hot or cold depending on the season. So, less energy is used, and you save money. In my last two houses, I had zone dampers and it has really helped.
Check with your HVAC contractor if your house could benefit from this retro-fit.
Wrap it like a Shiny Present
The last and final segment of my duct tour was to ask my guests if the knew if their ducts that are in unheated (unconditioned) spaces were wrapped with insulation. These ducts are usually found in a basement or crawl space. Mostly, I would hear, “uh…no,” or “I have no idea.”
For every foot of unwrapped or inadequately wrapped ducts, you are literally throwing you money out the window. Check here and here for the R-value guidelines for insulating your flexible and metal ducts.
Make sure all ducts in unconditioned spaces are wrapped including crawl spaces. This includes flexible ducts as well. In addition, use a formaldehyde free duct wrap such as Microlite XC from Johns Manville. (This product is in my home.) I am not a fan of anything with fiberglass since it makes me cough and itch if I am around it. If anyone knows an R-6-8 non-fiberglass duct insulation, please let me know.
At the end of my tour, I made them all promise that they would go home and look at their ducts in the attics and basements including the crawlspaces.
If you suspect you have vermiculite insulation in your house, do not disturb it, and call a licensed contractor. (See the pictures in the hyperlink.) Vermiculite insulation might contain asbestos.
Are you disconnected?
In my previous house, one of my flexible ducts was not connected properly. As I put my hand around the bottom of the tube, I could feel cold air just pouring out of the duct. I was cooling my attic. Make sure all of your ducts are securely connected to their truck lines (to the rigid sheet metal) and the boot (which is the opening into the floor or ceiling.) Also check to see that there is adequate insulation around the boot and that the flexible duct is not torn.
It is a good idea to have your air conditioning and heating system checked for leaks by a HVAC contractor since it will save you money in the long run. Now, that we have the ducts under wrap, tomorrow’s discussion is tuning up your heating system.
Go check your ducts, and report back to me!