Heat source emissions
Live emissions comparison for heat pumps, gas furnaces, and electric resistance — using real outdoor temperature and grid carbon data for your city.
Switching from a gas furnace to a heat pump is one of the highest-impact changes a household can make — but whether it actually reduces emissions depends on two things that vary by location: how cold it gets outside, and how clean your electricity grid is.
This tool uses your city's live outdoor temperature and real-time grid carbon data to calculate and compare the emissions from three heating options. Enter your city and your current furnace efficiency to see how they stack up right now.
Grid carbon intensity — last 24 hours
Monthly emissions — gas furnace, heat pump & optimal hybrid
Hourly analysis using 2025 Alberta grid data and Calgary temperature data. The optimal hybrid switches between sources hour by hour based on real-time grid carbon intensity. Based on a typical 185 m² home.
Heat pumps don't generate heat — they move it
A gas furnace burns fuel to create warmth. A heat pump works differently: it extracts heat energy that already exists in the outdoor air and moves it inside. This is why it can deliver more heat energy than the electrical energy it consumes — often two to three times more. Even at -15°C, there's still usable heat energy in the air.
COP: how much heat you get per unit of electricity
The Coefficient of Performance (COP) measures a heat pump's efficiency. A COP of 2.5 means you get 2.5 units of heat for every 1 unit of electricity used. A gas furnace, by comparison, always has a COP below 1 — some of the fuel's energy is always lost up the flue. COP drops as temperatures fall, which is why cold climate models matter in places like Alberta.
Grid emissions vary enormously by location
The carbon footprint of electricity depends entirely on how it's generated. Quebec's grid is nearly all hydro — among the cleanest in the world. Alberta's grid has historically leaned on natural gas and coal, though renewables are growing fast. A heat pump in a high-emissions grid region may not outperform a high-efficiency gas furnace today, but that calculation improves every year as grids get cleaner.
How to read the results
The numbers show kilograms of CO₂ equivalent emitted per gigajoule of useful heat delivered — a common way to compare heating systems on equal footing. Lower is better. The green-bordered card is the lowest-emissions option for your location and conditions right now. Try changing your city to see how much location affects the outcome.
Why a hybrid system can beat a heat pump alone
Alberta's electricity grid isn't clean at a constant level — it fluctuates hourly as wind and solar generation rises and falls. On a calm winter night, the grid may be running almost entirely on natural gas, making electricity relatively carbon-intensive. In those hours, burning gas directly in a furnace is actually the lower-emissions choice, even accounting for the heat pump's efficiency advantage.
An optimal hybrid system responds to this in real time: run the heat pump when the grid is clean, switch to gas when it isn't. The cutover temperature shown above is the threshold at which one source becomes better than the other at the current moment. This is why the hybrid bar in the chart below can be lower than both the pure heat pump and gas furnace in certain months — it's always using whichever source is cleaner for that specific hour.
At CWM, transparency comes first
We don't believe in hype or oversimplifications. Instead, we focus on transparency and backing up our insights with solid data.
The COP data used here is derived from a representative cross-section of real-world examples for each heat pump type. While performance is shown as a single line for simplicity, it exists on a spectrum — several factors affect real-world results:
- Variations between models and vendors
- Differences in air handling units and ducting in your home
- Environmental factors like whether the unit is installed in a sunny or shaded location
Got feedback? Let's talk
We strive for accuracy, but no system is perfect. If you think we've missed the mark or have suggestions for improvement, we'd love to hear from you. We're passionate about the details and always eager to dive deeper into the data.
Share your feedback →This tool is designed to provide general insights into the potential differences in CO₂ emissions between various heat sources. It is intended for informational purposes only and should not be used as a substitute for professional advice or decision-making.
- No design or operational guidance: This tool does not provide recommendations or specifications for the design, installation, or operation of any heating systems.
- Consult the experts: If you are considering a heat pump or any other heat source for your home, consult a qualified HVAC professional with experience in heat pump systems. A knowledgeable technician can provide tailored advice and ensure proper installation.
- Installation matters: The quality of installation plays a significant role in system performance and customer satisfaction. For the best results, always work with reputable and experienced professionals.
By using this tool, you acknowledge that all decisions regarding heat source selection and installation are your responsibility and should be made with the assistance of qualified professionals.