This forum and the pros that contribute are excellent. What a tremendous resource. I've read a ton of posts to help with a BIG decision i have to make in a few weeks. There are many posts about similar situations but none exactly like mine. Below is a brief description of my situation. Hopefully there are some of you out there that can steer me in the right direction.
I live in Houston, TX and am buying a house that was built in 1962. It is a 1.5 story ranch with 3376 total sq ft (2217 sq ft downstairs, and 1159 sq ft upstairs). The front faces north and trees shade about 1/3 of the house. There are approx 13 windows down and 6 up; most are single pane with some of the larger ones being double pane. The existing Amana HVAC system was installed in 1993 and has a single 5 ton condenser and 80,000 btu furnace. The furnace/airhandler is located in the top attic. Ducts are the original insulation-wrapped tin and are in good shape. I have not lived in this house and have no idea how it heats and cools with the current system. We are having new insulation installed in the attic so it will be up to current r-value standards.
The Amana system is shot and needs to be replaced before next summer. I plan on having a new system installed when we move in, which is where the dilemma starts. I am on a limited budget so money is factor, but so is comfort. I want to find the happy medium between comfort and cost. We plan on being in the house for a while.
Here are the conclusion's I've made so far:
1) I definitely want a 2-stage condenser coupled with a variable speed air handler.
2) I like the Trane system in my current house. It's a XL19i and has been bullet proof. I wouldn't mind staying with Trane.
3) I'd like to keep the existing ducts since they are in good shape and to cut down on cost.
4) The sq ft of the house is right on the cusp of being too much for a single 5-ton unit.
5) We've had 2 HVAC companies look at the house and are awaiting quotes. Both felt that a single system properly zoned will work.
Here are my questions:
1) Are the conclusions mentioned above accurate?
2) Will a single system with 2 zones (upstairs on one zone and downstairs on the the other) adequately cool the house?
3) If I go with a zoned system how can I know it's being installed correctly?
4) Should I broaden my scope outside the Trane name?
I am just at a loss for what to do. I don't want to make a bad decision and regret it later. But i also don't want to break the bank. Any advice or guidance you guys can offer is GREATLY appreciated. Thank you in advance for your time.