I've learned a lot from the forum regarding what to look for as a replacement HVAC system, but it seems the more I learn, the more questions I come up with.
I have a 2200 Sq ft, 36 year old house in the midwest, where winters are inconsistent but typically have lows in the 20's and every couple of years some zero degree days that hang around for a week or so. Summers are usually hot and pretty humid.
I'm looking to replace a 19 year old Lennox unit, and have followed your advice by having 4 or 5 of the more reputable contractors in town in to discuss a new system.
Not one of them has done a load calc or checked my ducts or insulation as the forum seems to suggest is a necessity. They more often look at the old equipment and ask a few questions about our plans to stay in the house.
My thoughts are to go with a 90+ furnace with variable speed blower.
My current unit was listed as a 100,000 BTU's and had an 81% AFUE rating when new.
One of the guys that has taken the time to talk through my questions has recommended a 80,000 BTU American Standard furnace with a VS blower and a 93% AFUE rating. I was concerned that going from my current 100k btu to a new 80 would be a capability issue, but he says the 80 will be plenty to heat my house, and do it more efficiently.
It sounds logical but does this make sense?
He also initially recommended a AM Std Allegiance 12 AC, and says that when paired with the correct coil and the VS blower on the furnace, it will comfortably produce a 13 SEER rating. My old Lennox was an 11 SEER at the time so I would guess I should see some efficiencies.
I did ask his thoughts on just moving up to the new minimum standard of 13 SEER, and he said that I could move up to the Allegiance 14, but that his chart shows the SEER rating only going to 13.75 on a 3 ton unit.
The next option in the American Standard line is an Allegiance 16, which has a 2 speed motor. He did say this one would give a big boost to the SEER rating and also control the humidity well, but it's more costly too.
Obviously it’s my decision whether to spend the extra bucks, but since I plan to stay in the house I want to be comfortable while I'm here, and I am thinking the extra money up front seems like it might make sense.
All said, I'm thinking of this 80,000 BTU and possibly the 16 SEER AC. The brand itself seems to read OK in consumer guides, and the contractor has a good rep.
Does my choice make sense?
Any help or advice is appreciated.
Variable speed ,two stage gas and two speed/stage compressor,will provide the best in indoor comfort.Protect the equipment with a Minimum merv 8 rated filter,because your indoor coil is a merv 6 filter,don't let the coil be the best filter in the system!
Carrier has a better control system,but what is propose is very good.
First as far as the furnace being big enough, I really can't say. I can tell you this, a 100,000btu furnace at 81% efficiency delivers 81,000btu, a 80,000btu at 93% effieciency delivers 74,400btu.
As far as ac goes I think a 16seer woul be a an over kill for your area. I don't ever think you would get your money back out of the system. I would go with the 13seer.
The american standard frunace is basically a Trane furnace which is good. If you want the best I would check out a Rheem Mod90 furnace. This is the only furnace with a variable speed blower and gas valve.