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

Guys, I have gotten stuck in between two systems for my final decision. Please help me out to pick the right one. I am trying to decide in between these two ; #1 - Bryant 6129135 Active Systems BRYANT HEATING AND COOLING SYSTEMS PERFORMANCE 13 PURON HP BRYANT HEATING AND COOLING SYSTEMS 286BNA048****B CNPV*4821AL*+UI 1300 1040 315(A,J)AV048090 45500 11.50 15.50 46000 8.20 29600 1 HRCU-A-CB 355 1140 also includes - Evolution touchscreen thermostat and comes with free Bryant Air purifier - one year test drive - I don't know how it works but they say they will provide 100% refund if I am not satisfied with the system within a year from the installation date #2 - Trane 5768796 Active Systems XR17 TRANE 4TWR7048A1 4TXCD063BC3 1370 1090 *UD2C080B9V4 48000 12.50 17.00 45500 9.00 30400 1 HRCU-A-CB 342 1077 Yes Not include thermostat. will use exiting HW VP IAQ includes GPS-2400 plasma air cleaner price wise the Trane is roughly $200 more expensive than the Bryant after the tax credit is deducted Both contractor will add two returns and one supply and will fix the distribution issues in my current duct work. Based on the notion I got; both contractors are very capable and have very good reputation I am more inclined to Bryant due to evolution controls. I do know Trane is very reliable and efficiency wise it is a little more efficient compared to the Bryant system. to me $200 difference in price is very negligible. I just want to make right decision. I got stuck! PLEASE HELP...

mike_home, I used indoor winter design temp of 78F and summer 70F; for outdoor I used winter 18F and summer 91F. For wall and attic insulation values, I used R11. All windows are double pane. tigerdunes, I gave the wrong AC model number, sorry, it should be 24ACC624A003. I think you are right about oversizing. Now I remember most of the time High-stage heat ran was when recovering from set back. In the few mornings when the outside was 10-15F, the furnace ran about half time High- and half time Low-stage. I was debating between 60K or 80K BTU. After getting a professional calculated Manual J of 120K BTU (as a part of energy audit), I picked the higher one:( I like your suggestion of a 3-ton AC, which will be consistent with the 5-ton total cooling from the professional Manual J. Considering I have an 80K BTU furnace downstairs, do you think 40K BTU will be fine? Will the blower generate enough CFM for the 3-ton AC? Thank you both for your advice! Jeff

Sizing can be less of an issue when you have multiple units. Because each unit is controlled independently, provided of course the unit itself is not over sized for the area in which it serves resulting in excessive short cycling. In your case 3 ton plus 2 ton isn't necessarily equal to 5 tons of cooling... unless you drive those thermostats really low. By having two systems with total capacity of 5 tons (which, most of the time this would be oversized for a 1700 - 1800 sq ft structure) has a few advantages. 1. You have the ability to use one system only during low heat days or set the opposing unit higher. The unit set higher only runs if load conditions warrant.... meaning if it's not hot, the thermostat controlling the unit does not call... the unit can not run without a call... 2. Utility bills can be much less... because you rarely use both systems at the same time. You run the bedroom system when you sleep, the other when you're awake. If you have a home office in one the bedrooms you may need to rethink things a bit. 3. Extra capacity for when it's hot out. When it's hot you have the capacity to cool the home. (even while entertaining guests --- additional people add heat) Remember heat waves come, heat waves go... a so call 'properly sized' AC system is essentially properly sized roughly 10% of the time... especially if that system is a single speed AC system. Alot of people I come across like to sleep cool. So for that reason I doubt I would change the configuration of the space. Once you realize what you have, the choices you make are mostly budget type concerns. Essentially a set up like this runs like a 2 stage system. This kind of subject is above the pay grade of many... choose your contractor wisely. I service the Katy, Texas area.