We recently installed one of those Heil 100,000BTU furnaces with the DC fan motor. It's got 3 dip switches to set fan speed during A/C calls. It's set to the recommended speed (1 less than max) for our 3-ton compressor.
Unfortunately, the furnace is in the basement right under the family room and the fan noise is very loud when it kicks on. I'm wondering if it would be a bad idea to try cutting the fan speed back one notch? An alternative idea would be to hook up a humidistat to the Y2 terminal, which would automatically cut the fan speed back 20% if the humidity is high (and believe me IT SURE IS!).
OR...as another possiblity...are there ways to make the ducts quieter?
After scratching my head on this for a couple of weeks, I've decided that it's probably a bad idea to have the furnace where it is....but moving it seems completely out of the question.
BTW...this new furnace cools like a dream. I put in a new Honeywell electronic thermostat and it holds 76 degrees 100% of the time. In 90 degree weather, the A/C calls are about 1 every 25 minutes and they last about 5 minutes. I guess I'd like to keep the good performance and lose some of the noise. Probably impossible, but you guys would know better than me.
Thanks for any advice!