Waste..... Foaming the walls is a waste. Go to any green building forum and it is almost universally felt that foaming walls is a waste of money. The foam salesmen are about the only ones that disagree. In my east facing house with 2x4 fiberglass batts, the walls and attic only account for 20% of total heat gain (energy audit). You are going to spend $10k to make that 20% come down to 15%. I have a similar size house in NC and I spent about $20k on Carrier Infinity 15/16 with heat pumps and 90% NG furnace and zoning and humidifier. So I think the $36k is absolutely crap. But $11k is a bit ridiculous also given the specs. In fact- I just can't believe it. Manual J is required in NC by code - so I don't know what to tell you. It is standard around here for quotes/bids. Oversizing sucks. 2 stage helps compensate. An is an air quality thing more than anything else. It is rarely cost effective. Texas is big - what is your area and ideally what is your HDD and CDD? Here is what I would do - presuming you live in a 90% cooling area. - Build with 2x4s and sheath the house in 1 inch rigid foam. If it really hot, you could go to 2 inches of foam. - Focus on minimizing East and West windows. If you can't - then really focus on low SHGC windows. All windows are low-e nowadays but SHGCs vary considerably - there are basic windows at .2 and .45 - a rather huge difference. Overhang the windows as much as you can tolerate. Big deep porches. Do those things and you should be able to get down to 2 2ton units which you should be able to get for $10k for seer 15 or 16. Most people don't find it worthwhile to get seer 18 equipment. Usually with new construction, you can spend that $5k (or whatever) on shell improvements (windows, overhangs) and get a better permanent ROI. There is no disagreement anywhere that 2inches of rigid foam on a 2x4 wall filled with blown cellulose outperforms a 2x6 wall with spray foam (and does so at a lower cost). Lastly - why an unvented attic? Because the ductwork is there? The best practice is to get the ductwork out of the attic in the first place. It is cheaper and far more cost effective. My personal house (4000+basement) would cost $10k to spray foam the attic at a estimated annual savings of.... $70. How about that ROI....

I live in the Philadelphia, PA area. My outdoor design temperatures are: Summer, 90; Winter, 14. Your area: Summer, 81; Winter, 36 with lesser humidity. My house is 2500 sq ft with good to very good construction. My indoor temps are: Summer, 76; Winter 66. The house requires 60,000 BTUs for heating; 3-1/2 tons for cooling. I could heat my house with your furnace 90 - 95% of the time. Of course, you can't just divide my figures in half to get yours, but this is why a heat calc is absolutely necessary, and is most essential for cooling comfort as you need to control temperature and humidity. I'd be curious what your present furnace is like (model number and size, age, etc.), and how it works for you (frequent short cycles vs. medium to long cycles). v

Hi all, My current furnace is the following: Brand = Bryant Model = 310JAV066110AAJA 5 ton unit INPUT UPFLOW BTU/HR = 110,000 INPUT DNFL/HORIZ BTU/HR = 105,000 OUTPUT UPFLOW BTU/HR = 89,000 OUTPUT DNFL/HORIZ BTU/HR = 85,000 I had another contract came today. He also quoted me for 5 ton. He said that I have a 5 ton blower and that my duct should be able to handle 5 ton. He quoted me for bryant 15 seer 5 ton model 186 for about $5000. Any thoughts on bryant brand? he said he also carry american standard but it will cost more since he gets better pricing for bryant. Thanks. This post was edited by j1stealth on Fri, Sep 13, 13 at 19:49

Another quote today ⢠New furnace 3 Ton brand(TRANE)model" XL80 >(3TON,60,000 BTU)2stage ⢠New condenser unit 3 Ton brand (Trane) model XB 16 up to (16.5 seer) ⢠New coil 3 ton brand (Trane) matching coil ⢠New thermostat digital (2 stage) ⢠New filter, Condenser Pad ,disconnect box ⢠New gas flex ,safety switch ⢠Remove old duct and old system ⢠Install new duct flex R6 ⢠Add 1 supply ⢠Seal all connection, connect drain line ⢠10 years warranty for parts, 10 years compressor, and 2 years labor ⢠Duct testing, city permit ⢠Run and test the system Total to pay: $6,221.00 include (Tax, Parts, Labor, Permit) Thoughts on this setup and price? Have had two companies that i questioned the size of ac and both said due to the high temps here...up to 110 at times, that 3 ton was best.