A couple of quotes and a few questions
I am in need of air conditioning in my house. Both units are currently inoperable. I have three quotes and am not sure which to go with. Also, if anyone if from the Raleigh, NC area and can confirm I am dealing with honest companies it would be very appreciated.
I will try to include all the information below (after reading through some other posts of this nature)
approx 3000 sq ft
built in 1986
two hvac systems that appear to be original:
downstairs: 2 ton trane compressor and some sort of old gas furnace
upstairs: 3 ton trane compressor and a newer (compared to the rest) 80% afue furnace
windows are single pane glass with storm windows over
located in Raleigh NC so hot and humid summers
Mostly shaded throughout the day so the house temps inside arent too bad considering... 95 outside and about 80 inside. The shade keeps it very humid inside though.
1) Trane 90XB gas furnace downstairs (60,000 BTU TUC1B060A9361A). 3 ton 15XLi upstairs (X5036C1000A) and a 13 XR downstairs (4TTR3024). Coils are 2 ton (4TXCB024) and 3 ton (036BC3HCA). They will also replace all supply ducts in the attic. Includes 2 pads, 2 programmable TCONT800AS32DA thermostats, return plenums, supply plenum, duct transition, breaks, pvc flue pipe, copperlines, pan, and float switch.
2) Goodman 95% 2-stage and 80% variable gas furnaces (60,000/100,000 BTU GGMH950703BX). 3 ton upstairs (GSSX140361) and 2 ton downstairs (GSSX13024). Coils are 2/3 tons (GCHPF3636A6). They will also replace all supply ducts in the attic. Includes 2 pads, 2 programmable TCONT800AS32DA thermostats, return plenums, supply plenum, duct transition, breaks, pvc flue pipe, copperlines, pan, and float switch.
I also got an option from them for a 14 seer unit upstairs that does not need to replace the furnace with a variable speed unit. So the price is cheaper on this option.
3) Carrier Performance two-stage gas furnace (60,000 BTU 58MTB060-F-1--12). 3 ton carrier comfort a/c condenser upstairs (24ACA336A003) and a 2 ton downstairs (24ACA324A003). The coils are CNPHP3617ATA for upstairs and CNPHP2417ATA for downstairs. They will also include transitions, pan and float switch, flex duct in attic, supply plenums, return plenums, piping, pvc vent pipe, digital non-programmable thermostats, power wiring to disconnect box, and pads.
Are there any pluses or minus with any of the above systems? They all also gave me an option to add on some sort of air filtration/purifier unit. Is this worth it?
Thanks in advance for any advice!
Sounds like everyone is over sizing the furnaces.
Most likely they are oversizing the A/Cs.
Have any of thes contractors done a load calc.
If not, ask them to.
If they won't, call other companies until you find one that will. They will most likely be teh contracgtor to use.
Forgot to mention one thing
One thing I did forget to mention was that the upstairs unit has to cool and heat the whole second floor which includes the bonus room above the garage and a third floor finished attic space (approx 2000 sq ft total). Most have said I will most likely have some problems cooling off the third floor properly (which I can live with).
Originally Posted by beenthere
That makes the A/C size sound better.
But the furnace still sounds oversized.
new HVAC units
Beenthere, you sound like you know HVAC, I have a simalar situation I'm replacing 8 seer units 18 years old with new 13 seer units. The down stairs unit is 2 ton and runs Okay and cools the lower part of the house but runs about 80 % of the time when it's 95 F out side. I've been told this is good running time so I'm replacing it with a 2 ton 13 seer.
How ever the upstairs unit is 2.5 ton and runs all the time when out side temp gets up to 85 F and will not shut down until late in the night when temperture drops. Also it will only pull the house down to about 78 F when out side air is above 85 F. So I set the stat on 78 F and hold so the house stays at a resonable temperture.
Question is should I move up to a 3 ton up stairs or a more efficant 13 seer 2.5 ton will work?
Its possible youor upstairs unit is undersized.
Before just increasing the size of your up stairs unit.
Can you add insulation to the attic.
A higher SEER A/C will not cool better if its under sized then an 8 SEER did undersized.
To increase size. You may have to increase return size, and add one or 2 supplies.
A load calc would tell you if you need a 3 ton for the second floor, or need to look for other problems.