How Does a Heat Pump Work in Cold Weather? | BC Winter Guide | ROMA
A heat pump works in cold weather by extracting heat from the outdoor air — even at temperatures as low as –30°C for cold-climate models. The physics: even at –15°C, outdoor air contains substantial thermal energy. A heat pump’s refrigerant cycle extracts and concentrates that energy to heat your home. ROMA Heating & Cooling has been Greater Vancouver’s trusted HVAC contractor since 1999. We’re TSBC-licensed, fully insured, and rated 4.8★ by over 158 verified customers.
The Physics of Cold-Weather Heat Pump Operation
A heat pump moves heat rather than creating it by using the refrigeration cycle in reverse. In heating mode:
- Liquid refrigerant flows through the outdoor coil, absorbing heat from the outdoor air (even in cold temperatures, air contains heat down to absolute zero, –273°C)
- The refrigerant evaporates into a gas, carrying the absorbed heat
- The compressor raises the refrigerant gas pressure and temperature
- Hot high-pressure refrigerant gas flows to the indoor coil, releasing its heat into your home’s air or water
- Cycle repeats — continuously moving heat from outside to inside
Heat Pump Performance at Cold Temperatures
| Outdoor Temperature | Standard Heat Pump Efficiency | Cold-Climate (H2i) Efficiency |
|---|---|---|
| +5°C (typical Vancouver winter) | COP 3.0–4.0 (300–400% efficient) | COP 3.5–4.5 |
| –5°C | COP 2.0–2.5 | COP 2.5–3.5 |
| –15°C | COP 1.0–1.5 (may not work) | COP 1.5–2.5 (full capacity) |
| –25°C | Minimal operation | COP 1.0–1.5 (reduced capacity) |
Why Cold-Climate Heat Pumps Work Better in BC
Brands like Mitsubishi H2i and Daikin Aurora use variable-speed inverter compressors and modified refrigerant circuits to maintain high capacity at extreme cold. In Greater Vancouver’s climate (rarely below –8°C), even standard inverter heat pumps perform excellently. Cold-climate models provide an extra margin of safety for Fraser Valley homes.
Defrost Cycles
When outdoor temperatures drop near or below 0°C, frost can form on the outdoor coil. Heat pumps automatically reverse the refrigerant flow briefly to defrost the outdoor coil — this is normal and expected. During defrost (typically 5–10 minutes every 1–2 hours), the backup heat source (electric strip or gas furnace) briefly activates to maintain indoor comfort.
Service Areas
We install cold-weather heat pumps throughout Vancouver, Burnaby, Richmond, Surrey, Coquitlam, New Westminster, North Vancouver, West Vancouver, Port Moody, Port Coquitlam, Delta, Langley, Maple Ridge, Pitt Meadows, and Abbotsford.
- Do heat pumps struggle in Vancouver’s rainy winter weather?
- No — rain and humidity do not significantly affect heat pump performance. The outdoor unit is weatherproof. Mild wet weather at +2°C to +8°C (typical Vancouver winter) is actually one of the most efficient operating conditions for heat pumps — the air contains more heat energy than dry arctic air at the same temperature.
- What temperature is too cold for a heat pump in BC?
- Standard heat pumps become inefficient below –15°C. Cold-climate (H2i) models from Mitsubishi, Daikin, and Fujitsu operate down to –30°C. In Greater Vancouver, temperatures below –10°C are rare enough that even standard models perform well — but for Fraser Valley and higher-elevation BC homes, we recommend cold-climate models for peace of mind.
- My heat pump is blowing cooler air than my old furnace — is this normal?
- Yes — this is a very common observation. Gas furnaces heat air to 55–65°C supply temperature. Heat pumps heat air to 35–45°C — still warm enough to heat your home effectively, but perceptibly different coming out of vents. Heat pumps compensate by running longer cycles at lower temperatures, which is actually more comfortable (fewer hot-then-cold cycles) and more efficient.
- Does a heat pump need a backup heater in BC?
- All ducted heat pumps include electric resistance backup strips for extreme cold (-15°C and below) or during defrost cycles. In Greater Vancouver, backup heat is rarely needed — maybe 20–30 hours per year during cold snaps. Hybrid systems use a gas furnace as backup, which is more efficient than electric strips when temperatures are extremely cold.
- Will my heat pump freeze up in Vancouver’s winter?
- Some frost on the outdoor coil is normal at near-freezing temperatures — the defrost cycle handles this automatically. Excessive ice buildup (covering the entire coil) indicates a problem with the defrost system, refrigerant charge, or airflow obstruction. ROMA diagnoses and resolves defrost system issues as part of our heat pump service.
Related Services
- furnace repair Greater Vancouver
- boiler repair Greater Vancouver
- heat pump installation Greater Vancouver
Book Your Service
Call ROMA Heating & Cooling at (604) 924-7273 or request a free quote online. Serving Greater Vancouver since 1999 — TSBC licensed, fully insured.
What Greater Vancouver Homeowners Say
“Nelson worked hard to get the NTI unit fixed. He was always polite, courteous and on time.”
“As always Nelson was super efficient. Showed up on time and was quick to work. I had a full maintenance done on the fireplaces and furnace. He was awesome. I won’t use anyone else.”
“Excellent service. Andy had a spare Carrier inducer with him which saved us time.”
“Was very prompt to respond to our issues. Technician was scheduled for the day following my initial call.”
“Very professional heating company. Price is reasonable, excellent work.”
“Highly recommend this company. It was a pleasure dealing with Shawn and Nelson.”
“Professional and courteous technicians with attention to detail and customer needs.”
“Always great, friendly service. Serviced the hot water on-demand system. Honest and informative. Thanks!”
“Speedy response time, honest, and professional service from start to finish.”
Why Greater Vancouver Trusts ROMA Heating & Cooling
ROMA Heating & Cooling has installed, repaired and maintained heating and cooling systems across Metro Vancouver since 1999. Our team are TSBC-licensed gas fitters (Gas LGA0202903) and Red Seal-trained technicians — licensed, bonded and insured — and we back every job with upfront, flat-rate pricing and a 100% satisfaction guarantee. We hold a 4.8★ rating from 221+ Google reviews.
- Authorized for 30+ brands (Lennox, Carrier, Viessmann, Navien, Rheem & more)
- Upfront flat-rate pricing — no overtime or hidden fees
- Free, no-obligation estimates on new installations
- Locally owned & operated in Burnaby, BC
No Hidden Fees
Our service rates are transparent and easy to understand. You approve upfront, flat-rate pricing before we start — so you never get a bill you didn’t expect.
Licensed & Bonded
ROMA is a TSBC-licensed gas contractor (Gas LGA0202903). Our technicians are bonded, insured and Red Seal-trained — qualified for any heating or cooling system.
Free Estimates
We offer free, no-obligation estimates on new installations — furnaces, boilers, heat pumps, air conditioners, tankless and hot-water tanks.
ROMA Heating & Cooling is a trusted HVAC contractor serving Metro Vancouver since 1999. We specialize in furnace repair, heat pump installation, boiler services, air conditioning, and emergency heating solutions for residential, commercial, and government clients. Available 24/7, our certified technicians deliver fast, reliable, and affordable HVAC services across Greater Vancouver.