Having my first meeting with the guy designing our HVAC system for our house. We are contemplating building a 6000 sq ft house with full radiant heat. What questions should I be prepared to ASK or ANSWER to make sure we spend our time efficiently?? THANKS!
Since you're paying for their expertise, I would suggest listening to what they propose and then get some opinions. You want them to bring their expertise to the table, and you don't want to steer them in a particular direction. Bottom line, you want comfort and efficiency. See what they propose to achieve that. If you then have particular questions, or don't understand something, first present the questions to them and then, if the answers don't satisfy you, seek other outside opinions.
For a start, know what you want (pick from list):
1) Lowest capital cost.
2) Lowest operating cost.
3) Minimum temperature variation between rooms.
4) Do you want a high tech system with lots of gadgets (remote controls, thermostats in every room, Internet monitoring of wine cellar temperature, etc), or a simple system with one thermostat.
5) Ask about tradeoffs between insulation, air sealing, capital cost, and operating cost.
6) Humidity control during cool to warm, humid weather.
7) What about ventilation - air to air heat exchanger, high power range hoods, etc.
8) Special requirements - pet skunk, scented candles, smoker living with nonsmoker, etc.
Focus on what you want it to do, let him (her) figure out your options.