Hot attic with ducts and gas appliances, feel limited on what my options are
cdeg1003
| Posted in General Questions on
Hello,
My husband and I bought a small home built in 1930 in Texas (climate zone 2B). We finished renovating it a year ago. We are having some issues with our hot attic and our A/C overworking, possibly pressure issues in the house now that it is sealed so much better than before the renovation, and the smell of attic air in my son’s room where the attic hatch is (this is also causing me concerns around pollutants from the attic in living space air).
We have our air handler and ductwork in the attic which is unconditioned and vented. I now know after some research how bad this is for efficiency. We also have our gas furnace and gas hot water heater in our attic because these systems were not ready to be replaced yet. We want to phase out our use of natural gas and replace these with electric units when they are ready to be replaced. We have blown-in insulation on the floor of our attic (unfortunately we left the old blow-in insulation and just added new on top), two gable vents and a few static vents. Also, ducts are off the ground. So, here are my questions:
– What can we do to make our attic less hot and have our A/C not overwork? From what I read, we can’t make our attic a conditioned space because of the gas appliances we have in there?
– Should we remove old blown-in insulation and replace with clean blown-in insulation and make sure our attic floor is sealed properly to help with efficiency and reduce pollutants up there? Should we also add soffit vents or ridge vents and possibly a radiant barrier? I know many people think radiant barriers are not worth it.
– If we make it a conditioned space after replacing those appliances, can we use something else other than spray foam since it seems to off-gas for years? Like Hemp or something else less toxic under the roof?
-For our pressure issues, do we just adjust fan speeds on our A/C unit and check for duct leaks? Should we also adjust our air intake? We have this set for 5 min every hour. Should this be adjusted depending on time of year?
-The attic hatch in my son’s room has an insulated cover on the inside, foam board and foam weather stripping on the door on the inside. We are going to try and tape the door closed with gorilla patch and seal tape to see if it reduces the attic smell because we think the negative pressure in the house might be pulling air from the attic down into his room through this hatch. Any other ideas for this issue?
-Lastly, if I am worried about pollutants from the attic getting into our living space, is there anything else I can do? My son seems to have a runny nose and cough all the time.
Thank you for any help you can offer!
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Replies
To address your attic and HVAC issues, improve ventilation with soffit and ridge vents and consider a radiant barrier. Removing old insulation and ensuring proper sealing before adding new insulation can enhance efficiency. Once you switch to electric appliances, you can condition the attic using non-toxic insulation like hemp. Adjusting A/C fan speeds, checking for duct leaks, and modifying air intake settings based on the season can help manage pressure issues. Improve the sealing around the attic hatch, possibly with an attic tent, to reduce air leakage. Using an air purifier and ensuring good ventilation can help reduce pollutants and improve your son's health.
Thank you so much for your reply! I think I'm too worried about moisture issues with the radiant barrier, but I will do the rest and see how it goes. I do have air purifiers in the house and an attic tent. Hoping the tape along the attic hatch will help even more. Also, going to check light fixtures and other areas to seal better for preventing attic air getting in the house.
Just curious, how anyone finds HVAC or roofing companies they can trust? I have had too many people recommend things that have made things worse (like solar attic fans that caused our hot water heater pilot light to go out among other things-we now have them turned off and wasted all that money). Any recommendations for Austin, TX area would be appreciated!
You might find this article interesting.
https://www.energyvanguard.com/blog/buried-ducts-allowed-2018-building-code/
When the time comes to replace your HVAC consider going ductless with one outdoor unit for each indoor unit.
My wild guess is the ducts in the attic are very leaky and when the precious conditioned air escapes into the attic your home gets depressurized. 100% of that air will be replaced by air pulled thru a gap somewhere in the home.
Call the local HVAC companies and ask if they offer “Duct Blaster” & “blower door” testing for homes?
https://store.energyconservatory.com/minneapolis-duct-blasterr-system-with-dg-1000.html
A duct blaster is used it find and repair leaks in your ducts.
The way I see it a conditioned attic is only marginal better than the current situation.
I see no reason to replace old insulation it does not go bad Ideally you would have little air flowing from the attic into your home.
You could check for leaks with the HVAC blower running hold a burning incense stick holder near the any crack and see if leaking air disrupts the smoke.
Walta
Thank you Walta! The only thing is I thought I couldn't bury my ducts bc we live in Austin, TX so we would run into moisture issues? And we have talked about mini splits for the house, but just feels so expensive. So, yes, myabe when our A/C needs to be replaced. I will try checking our ducts though for sure!