Any HVAC experts out there?

[kiwichris]

Wondering if we have any HVAC experts out there who can help me out.

Need to replace outdoor A/C unit, currently it's a 2006 installed Trane 4 tonne unit (house is just under 2500sq ft finished).

Replaced the old carrier furnace 2 Xmas ago with Goodman model & am wanting to match but not sure if I can get away with a smaller, more efficient model than a like for like tonnage replacement.

Considering the 3.5tonne GSX140431 @ 42000btu but reading ac blogs it seems minimum I'd need is a 48000btu system.

 

[Thrillbilly Jim]

Paging @LLIB !

 

[DaBuckBoys]

By no means an expert, but I did replace my 1996 outdoor AC unit a couple years ago. The units are more efficient now and are larger but run slower. Not sure about a 2006 model, but likely also a different coolant that is much more expensive but not as bad for the environment (I think?). I'll have to check into the tonnage when I get home. Ours was a little undersized before but still lasted 22 years. Just under 2400sf house.

 

[LLIB]

By no means an expert, but I did replace my 1996 outdoor AC unit a couple years ago. The units are more efficient now and are larger but run slower. Not sure about a 2006 model, but likely also a different coolant that is much more expensive but not as bad for the environment (I think?). I'll have to check into the tonnage when I get home. Ours was a little undersized before but still lasted 22 years. Just under 2400sf house.

Actually R-410a (new stuff) is a lot cheaper than R-22 (old stuff). Also what do you mean run slower? That’s a new one

 

[LLIB]

Wondering if we have any HVAC experts out there who can help me out.

Need to replace outdoor A/C unit, currently it's a 2006 installed Trane 4 tonne unit (house is just under 2500sq ft finished).

Replaced the old carrier furnace 2 Xmas ago with Goodman model & am wanting to match but not sure if I can get away with a smaller, more efficient model than a like for like tonnage replacement.

Considering the 3.5tonne GSX140431 @ 42000btu but reading ac blogs it seems minimum I'd need is a 48000btu system.

If you had a 4 ton go back with a 4 ton. That’s what your duct system has been designed for. Unless you’ve upgraded your insulation, windows, doors, etc going smaller will only cost you $

 

[DaBuckBoys]

Actually R-410a (new stuff) is a lot cheaper than R-22 (old stuff). Also what do you mean run slower? That’s a new one

Guess, I mis-remembered. Just the year before replacing the old one we had a leak and had a shot of sealant and topped off with coolant. Guess thats the one that was expensive!

RPM's on the fan? New unit is quieter, old one sounded like a jet engine taking off...

 

[LLIB]

RPM's on the fan? New unit is quieter, old one sounded like a jet engine taking off...

New ones are the same or sometimes faster. Bearings and lubricants are better

 

[kiwichris]

Living in Colorado, anyone know the best seer rating without going stupid expensive?

 

[Blujacket]

4 tons for 2500 sf is oversized. The install is more important than the brand. Have your dealer do a Manual J

 

[LLIB]

4 tons for 2500 sf is oversized. The install is more important than the brand. Have your dealer do a Manual J

Not necessarily. Depends on how well the house is insulated and how the duct system was designed among other things

 

[Junkyard]

Oversizing air conditioning leads to short-cycling and cold but muggy conditions, because the system doesn't run long enough to remove the moisture. If I'm ever between capacities, I'll always go with the smaller unit unless it's a variable compressor since it matches the load.

If you don't have a ton of solar gain through windows I'd wager that you could get away with the smaller unit. As @Blujacket suggested, get the contractor to do a load calculation. Otherwise it's like buying golf clubs off the rack - they might work, but probably aren't going to be the best fit for you.