Florida is not the kind of place where you’d want to be without air conditioning for very long, so when Chris Marriner’s old system died last spring, he didn’t waste much time in replacing it. But what should have been a ticket to indoor comfort hasn’t exactly worked out that way.
Marriner’s HVAC technician decided to replace the 4-ton system with one of the same capacity, even though Marriner knew that because of improvements to the building envelope the new system probably would be oversized for the 2200-square-foot home. The tech told Marriner the system could be “tuned.”
In a Q&A post at GreenBuildingAdvisor, Marriner complains that indoor relative humidity averages 55% or more, and has ranged up to 66% or 67%.
That’s apparently because the oversized AC equipment doesn’t run long enough to lower indoor humidity. When Marriner spoke to the HVAC installer about the oversized equipment, he got some strange advice.
“I talked to him about it and he wants to bring some attic air into the return so [the AC] will run longer,” Marriner writes. “I think that adding a whole house dehumidifier, like the Williams Air Sponge, or Aprilaire would be the best solution. Any feedback?”
That’s the topic for this Q&A Spotlight.
HVAC tech’s idea is non-starter
Nathaniel G finds the suggestion to bring hot attic air into the system to extend the run time nothing more than an “inefficient Band-aid.” The system should have been sized correctly in the beginning.
“Sounds like your HVAC tech is less interested in doing his job properly than doing it the way grandpa did and upselling you on a bunch of crap to patch up his own mistakes when grandpa’s approach doesn’t cut the mustard,” Nathaniel says.