The general noise level produced by my furnace is too loud. I believe the main culprit is just the sheer volumetric flowrate being pushed through the ductwork. The blower by itself sounds normal. The burners put out a good bit of noise, but that is unavoidable I imagine. My house is 1-1/2 yrs old with a Rheem "Criterion II" natural gas forced air furnace. 125,000 btu/hr. Blower is 9.5 amps, 3/4 Hp. I think the blower is capable of 4 speeds, since a table printed on the panel shows the airflows for the 4 speeds. My house is 2700 sf, 2 stories, 10 registers up, 10 registers down, 1 zone.
Whenever my furnace turns on, the blower starts in a slower speed (without flame) for about 45 seconds, then the burners light and the blower shifts to a medium speed for about 30 seconds, then finally shifts to fast speed.
Is it possible to make the blower run at a lower speed? Is it safe (delta-T would increase)? Would the efficiency be changed? How can I accomplish the speed change?