1 stage or 2 stage AC and furnace hel;

[blaff]

I have an 11 year old, 13 seer, 1 stage furnace and AC which does the job with reasonable utility bills. I am upgrading to a 16 seer to take advantage of the tax credit. One option is a 1 stage furnace with multiple speed (high efficiency) AH and 2 stage AC and the other option is a 2 stage furnace with variable speed AH and a 1 stage AC.

I live in Tampa, FL where the furnace gets used maybe for a month or two in a typical winter and the temp gets below freezing maybe several time mainly overnight. Summers are hot and humid. The AC clearly is in demand most of the time.

Given the hot/humid months, will the AC be running at the higher speed most of the time anyway so why a 2 stage?

Is the variable speed AH more prone to problems because of more circuitry than the multiple speed?

Does one option justify a higher price point than the other?

Which option makes more sense?

Thanks!

[big sky hvac]

Personally for where you live, I'd invest more money into a higher efficiency A/C than into a 2-stage furnace. Your cooling season is much longer than your heating season, so for me it would be hard to justify spending extra money on a furnace. I think you'd see more money back in operating costs from the A/C. Go with a single stage furnace and probably invest in the 2-stage A/C I guess. You may also consider doing a heat pump seeing how you live in a warmer winter climate.

[garya505]

Personally for where you live, I'd invest more money into a higher efficiency A/C than into a 2-stage furnace. Your cooling season is much longer than your heating season, so for me it would be hard to justify spending extra money on a furnace. I think you'd see more money back in operating costs from the A/C. Go with a single stage furnace and probably invest in the 2-stage A/C I guess. You may also consider doing a heat pump seeing how you live in a warmer winter climate.

Considering the very low furnace usage, you could also ditch the gas and go with a heat pump and VS air handler with some heat strips. Depends on your electric rates though.

[blaff]

Thanks big sky. I don't want to switch to a heat pump so the 2-stage is more efficient than a one stage AC even if both are 16 seer?

Do you know if a multi-speed air handler is more reliable than a variable speed? Thanks.

[blaff]

Thanks Gary,
If I want to stay with the furnace, do you feel a 2 or 1 stage furnace makes sense?

Is the variable speed air handler more reliable than the multi speed especially if I go with a Trane? Thanks.

[big sky hvac]

Thanks big sky. I don't want to switch to a heat pump so the 2-stage is more efficient than a one stage AC even if both are 16 seer?

Do you know if a multi-speed air handler is more reliable than a variable speed? Thanks.

Electrically the variable speed will saving you more money on your operating costs. As far as reliability, that really depends on maintenace of your equipment. If you're dillegent about replacing your filter, you shouldn't have any problems. The heat pump would be good for heating when your temps. are in the 40's and 50's, then you wouldn't need the gas furnace until the temps drop under 40 and closer to freezing. You can get a 2-stage heat pump, so you'd have your heat pump for heating in warmer winter weather and 2-stage cooling for the summer.

[garya505]

Thanks Gary,
If I want to stay with the furnace, do you feel a 2 or 1 stage furnace makes sense?

Is the variable speed air handler more reliable than the multi speed especially if I go with a Trane? Thanks.

A 2-stage furnace in your climate is a waste of money.

Reliability? I think anyone who can really predict that is clairvoyant.

If you get the right combo with a VS furnace or VS air handler you can get a tax credit (until 12/31/10).