Originally posted by JoeSix
I see this stated occasionally, but don't see why it would be the case and in fact personally had a similar situation.
Originally posted by billygoat22
In some cases hi eff equipment cost more to run due to poor ductwork. A 14 seer will perform like a 7 seer if the duct is in poor shape.
A DC variable speed blower is most efficient under low static resistance, but can move almost twice as air through the same ductwork as a standard blower and still use less electricity as long as you're with in the limits of the blower.
If you're meeting the airflow requirements of the system, why would you lose that much SEER?
I had an installer put in a Lennox G60V and HS26 in my 1500 sq ft townhouse several years ago to replace the original builders grade equipment. The return space is definitely too small (not quite even 2 square feet) although the supplies are OK, and they put in a 2 ton unit when a 1.5 would be the right size (although too small for that air handler). My total peak electric bill dropped 25% afterwards from $60-70 in the hottest months to more like $45-50.
First 2 sq. ft of rturn is more then enough for two tons.Your system may be normal or even low static.
VS will draw much greater wattage at high statics,delivers the air required ,up to a point.After that point cfms drop off.
In either case running the fan 24/7 ,as encouraged in some mfrs. literature,and by contractors,really can increase the bill.
Well, this was a guess, and also the return goes into a deadspace under the closet that air handler sits on with a hole cut into the decking to allow air flow into the blower. This opening is 11" x 18", or less than 1.4 square feet. It can't be cut any larger because of the support structure put in under the deck. It bites.
First 2 sq. ft of rturn is more then enough for two tons.Your system may be normal or even low static.[/B]
Trust me, even at 800 CFM that return configuration generates more noise than anything else in the system. (Thank you, builder)
Meanwhile my new home has 1000 CFM going through 6 individually ducted returns feeding 12 supply registers. You can't even tell the system is running (well, in A/C mode) unless you look at the thermostat or put your hand over a supply register.