Looking for advice on a home heating/cooling problem, here's the story:
We have a two story house (2100 sq ft, almost equally distributed up and down) in central Texas (mild winters, somewhat hot summers). Lennox single 4 ton HVAC unit roughly 7 years old, single zone system. Summers aren't bad, although the upstairs rooms are a bit warmer than downstairs - nothing too unpleasant. Although two rooms (that face south and are over a two car garage) get pretty warm in the morning & afternoons. Winters on the other hand are completely different. The downstairs is consistently 10-15 degrees colder than upstairs. It's almost unusable on colder (30's) nights. We've tried small space heaters downstairs, but they really don't help much.
We've talked with several people about options and here are the leading three:
* replace single pane windows with dual pane * replace HVAC with a dual system, or more powerful (5 ton) with continuous fan * add damper system to current HVAC to create dual zone system
The problem is all three solutions came from people who sell that particular product, and all claim the same thing "this should solve 90% of your problem". The first two are pretty expensive, so for that money I expect more than a 90% solution. Also, I don't expect sales reps to recommend a product they don't sell, so I'm not sure I'm get a straight answer.
While money is a concern (I don't want to spend 50k to fix this) I am willing to spend a reasonable amount if it solves the problem (3-15k). We're going to stay in the house at least 10 years, but getting the system to pay for itself in energy gains is not the leading priority.
We've looked at vinyl vs. Anderson Renewal windows and love the Anderson windows, but the price is pretty steep and the sales rep was a bit odd. Vinyl through Home Depot seems to have a great warranty (haven't read the fine print), but it's still vinyl windows and I haven't been convinced they're going to last - and it still just seems wrong to have vinyl windows to me. They looked great until we saw Anderson windows.
A local company serviced our HVAC this year and when I asked the tech his advice, he seemed to think a damper system (~3k) would significantly help. We do have two returns (upstairs & downstairs), so adding a thermostat downstairs (the one we have now us currently upstairs) sounds good. He's the first person that's explained a damper system to me in a way that he sounds like he knows what he's talking about.
So there you have it - I would really appreciate feedback from someone (homeowner) who's done this and what the results were, or hearing from a general contractor on recommendations.
twostoryhvac at gmail dot com