Gas and Oil Home Heating Furnaces - Oversized Trying to decide b/w 2 stage and Variable Speed

I was told by Trane heating contractor that based on the heat-loss calculation I need 17,700 BTU. However, smallest furnace is 40,000btu. If I get a 80% then I assume this drops actual btu to 32,000. If I were to get a 40,000btu I would get the 2 stage. However, based on our conversations I would prefer a variable speed furnace due to the extra quiet operation. However, the minimum btu is 48,000. with an actual btu of 36,800.

Should I be worried about short cycling more with the variable speed furnace due to its increased btu?. Should I stay away from the variable speed b/c of the increased btu or is the additional ,4800btu not critical?.

Once again the square footage is around 875-900 square feet.



with the Trane 2 stage
btu in stage 1 btu in stage 2
is 20,800 is 32,000


with the Trane variable speed furnace
btu in stage 1 is btu in stage 2 is
31,200 48,000

with Bryant 2 stage
btu INPUT in stage 1 btu INPUT in stage 2
23,000 35,000


btu Ouptut in stage 1 btu output in stage 2
29,000 44,000

with Bryant Varialble Speed Furnace
btu input in stage 1 btu input in stage 2
35000 54,000

btu OUTput stage 1 btu output stage 2
43,000 66,000

Any suggestions. I would really prefer the variable speed but not sure if it makes sense based on the numbers.

I just found out that the Trane Btu is 60.000, According to the Trane contractor's calculations my need is only for 17.7K btu. 60,000 variable at 80% in 2 stage is now sounding more uncertain. I liked the variable speed due to its quiet operation. 2 stage would be 40,000btu.

look into the rheem modulating furnace, it may fit your needs, outstanding unit

THere is a smaller Trane. the TUD060R9V3K is 48,000 BTU on High, and 31,200 BTU on low.

To me, I wouldn't do the oversize.. it's just going to be a waste of gas while you get a blast of heat.. I take it you are just going to do the upstairs only???? I honestly think you would be much better off doing the whole house that way you are getting full use of your smallest BTU rating, and variable speed system.


HVAC, Rheem Mod would be a good ideal as well but furnace would be just a waste as well if he just going to put a new system alone in the attic. If the heat lost calls for 17k, The unit only going to run on lower stages 97% of the time.

Do like I did
Get a gas water heater if you don't already have one.
Then get a "fan coil" heating system that uses hot hater to heat a "radiator" then the blower circulates the air throughout the house.

http://www.firstco.com/faqua1.htm

The sweetest thing is you can vary output of the unit simply by adjusting blower speed, water flow or water tempature.
A 2 stage setup would be a simple 24v SPDT relay to control blower speed and a standard 2 stage thermostat.

JAY THE UNIT you are referring to is still 60K Btu.