3.5-Ton Heat Pump: Size, BTU & Cost
A 3.5-ton heat pump delivers 42,000 BTU/hr and suits roughly 1,450–2,450 sq ft, depending on climate. Here are the details.
What is a 3.5-ton heat pump?
A "ton" measures cooling/heating capacity — one ton equals 12,000 BTU/hr. So a 3.5-ton heat pump delivers 42,000 BTU/hr. It typically conditions a home of roughly 1,450–2,450 sq ft, with the colder your climate, the smaller the home it covers.
3.5-ton heat pump by climate
| Climate | Home size a 3.5-ton unit suits |
|---|---|
| Cold (Zone 5–7) | ~1,450–1,800 sq ft |
| Mixed (Zone 4) | ~1,800–2,150 sq ft |
| Mild (Zone 1–3) | ~2,150–2,450 sq ft |
3.5-ton heat pump cost
A 3.5-ton ducted air-source system typically runs $9,520–$12,880 installed. Estimate your exact price below. (The federal 25C/25D tax credit expired Dec 31, 2025 — factor in state and utility rebates instead.)
Do you actually need a 3.5-ton unit?
Tonnage should be set by your home's heat loss, not a rule of thumb alone. An oversized unit short-cycles and wastes energy; an undersized one cannot keep up. Use our size calculator with your square footage and climate, then confirm with a contractor's Manual J.
Frequently asked questions
What size home does a 3.5-ton heat pump heat?
Roughly 1,450 sq ft in a cold climate up to about 2,450 sq ft in a mild one — a 3.5-ton unit is 42,000 BTU/hr. Insulation, windows and ceilings shift it, so confirm with a load calculation.
How many BTU is a 3.5-ton heat pump?
42,000 BTU/hr — one ton equals 12,000 BTU/hr.
How much does a 3.5-ton heat pump cost?
A 3.5-ton ducted air-source system runs about $9,520–$12,880 installed, before any state or utility rebates. The federal 25C/25D tax credit expired at the end of 2025.
Other heat pump sizes
⚠️ Rule-of-thumb estimate, not a substitute for a professional Manual J load calculation.