Start with the house
The right system depends on how much heat your home loses on the coldest days and how much it gains on the hottest. A room-by-room load calculation, often called Manual J, answers that. Ask every contractor whether they will do one.
If you plan to add insulation or replace windows, do that first, or tell the contractor. A tighter house may need a smaller system.
Your climate
Heat pumps move heat rather than making it, and they lose some capacity as it gets colder outside. Cold-climate models are designed for long freezing spells. In the coldest regions, some homes pair a heat pump with a furnace that takes over on the harshest days.
Your fuel and your ducts
If you have gas and sound ducts, a furnace with central air or a heat pump on the same ducts are both options. Without ducts, a ductless mini-split avoids building new ductwork.
Ask what it costs to run each option in your area, using your own utility rates, not a national average.
Questions to put to each contractor
What size of system do you recommend, and what is it based on? What are the SEER2 and HSPF2 or AFUE ratings of the exact matched system? Which refrigerant does it use? What happens to my ducts? Who pulls the permit? What does the labour warranty cover, and for how long?
General information only. For wiring, refrigerant or gas work, use a licensed professional.
