"What are the major differences between 14 and 16 seers"

14 SEER units use one single-stage compressor as do most a/c units. They can use the old R22 refrigerant or the new R410A. 16 SEER typically uses a two-stage compressor and R410A refrigerant. A two-stage compressor will run on the first-stage and then shift to second stage if the first stage cannot provide sufficient cooling.

The Energy Efficiency Ratio (EER) determines true operating costs and not SEER. What is the EER of the 14 SEER and 16 SEER units? What is the price difference between the 14 and 16 SEER units?

I live in Baltimore and recently replaced an old 7 SEER with a new 14 SEER. I have reduced my electricity consumption by 40 percent in July and August '07 versus July and August '06.

Best to you.

Pretty said this guy would quote a 13 stage ultimate furnace and then cripple it with a mismatched stat. This furnace needs to be on the matching touchscreen stat. Period. It will properly give you all the comfort this furnace can offer. A Honeywell stat will not.

So Rheem makes a matching touchscreen thermostat? Do you know the model # or name of the thermostat that works the best with the 90% modulating furnace?
And thank you for the AC info. I will ask about the 14 SEER unit cost on Monday but if the difference is not ridiculous, I think we will go with the 2-stage 16SEER unit.

The charts say that area has around 900 hours of run-time for a cooling season.

Summer Design is 91 dry bulb 74 wet bulb, or approx. 44% RH. Depending on the initial cost differetial, that particular 16-seer might work okay in your climate.
I personally like he 14-seer with the lowe pressure R-22.

Winter Design at Wash. Natl. AP is; 97.5% 17-F.
Between seasons a Heat Pump might save on utillity bills.

Do what you can to reduce heat-loss heat-gain which wiill reduce costs for both heating & cooling.

udarrell _ 2007

Here is a link that might be useful: udarrell.com

Yes, Rheem has recently introduced a thermostat line for the Mod 90 series. Although anything that is propriatery which is required to obtain optimal control with the series is most likely one I would not purchase. In the long run it may will cost you more in replacement, product changes, and obsolesence. Furthermore, I wouldn't purchase ANY piece of heating or cooling equipment that requires a special thermostat. Why would the Honeywell Vision Pro cripple the features on this furnace?

Here is a link that might be useful: Mod 90

With the Mod stat, you get 13 stages of heat based on the needs of the home. With a Vision Pro you get 3 stages. If a single stage stat is used, the 3 stages are all timed. If a 2 stage stat is used, 40% fire is 1st stage, 65% timed to 100% is 2nd stage. Why buy a superb furnace like this and not sure the thermostat that will take advantage of all the furnace can do?

To get the most out of a Carrier Infinity or Bryant Evolution, you need their special control. Next A-S & Trane will have a 3 stage 90 that will require a proprietary stat to run it.