While I was rolling through the HVAC assignment and taking notes up in the attic for the essay the unit cycled off and there’s a distinct popping sound coming from the air return plenum. I checked the returns around the house making sure they were not blocked by furniture.
I’m at a loss why this is happening. My system is a Goodman, installed when the house was built in 2020. I defer to the HVAC pros here, what can be causing this “pop” after the unit cycles off? Is there a fix or remedy? Thanks in advance.
Your return duct is under negative pressure when the blower is running regardless of any sort of restriction. The problem is likely that there is no cross-break on your plenum. They literally use the press break to form an X or cross pattern, hence the term “cross-breaking”.
Thank you Richard. This plenum is packed on all sides but the top doesn’t have a cross-break. So unless I plan on replacing or upgrading the unit the pop is permanent … perfect!
Excellent idea, I’ll try it. Just realized I took pics of the supply but the return isn’t any better. I can’t access or see the other side (no return ducts there), that would be a bear to try and get to for tape.
If you include the entire post as a “quote”, it won’t show in your post. Leave out one symbol, word etc. and it should. In other words, highlight up to the last period etc, then quote. It should work that way. I left out your “?”
Most of the time this is caused by expansion and contraction of rigid ducts as air is blown through them. How often it happens can also depend on the thickness of the metal used. When ducts heat up, they expand and pop, when they cool down, they contract and pop.
Thats why the better installations put a fabric “expansion sleeve” in the ducts by the furnace.
