You may have heard about the proliferation of heat pumps across residential properties in Ontario. Once considered suited only for milder regions, heat pump technology has evolved to perform well even in Ontario’s cold winters. The energy efficiency savings are impressive, but are heat pumps the right fit for every home? Can they fully replace a furnace or a central AC unit? And what kind of cost savings can you expect?
At DeCarli Contractors, we do make use of heat pumps, especially in certain situations. Let’s have a look.
What is a heat pump and how does it work?
A heat pump is an all-in-one heating and cooling system that moves heat using a ‘refrigerant change-of-state cycle’ rather than generating it through combustion (natural gas, propane, oil) or electrical resistance (electrical heating element). In winter, it extracts heat from the outdoor air—even in freezing temperatures—and transfers it inside. In summer, the process reverses, acting as an air conditioner by removing heat from the home and releasing it outdoors.
Heat pumps run on electricity, but unlike traditional furnaces or baseboard heaters, they don’t rely on consuming large amounts of electricity to generate heat or cool; they use small amounts of electricity to perform (pump) the ‘refrigerant change-of-state cycle.’ This is what makes them highly energy efficient. For every unit of electricity used, a heat pump can deliver three or more units of heating energy—far more efficient than electric baseboards, resistance heaters or a traditional AC unit. A heat pump can be a great investment, but choosing the right system and using it correctly is key to long-term comfort and savings.
Are heat pumps reliable in Ontario’s climate?
Older heat pumps struggled in colder temperatures, but modern cold-climate models are designed to handle Ontario’s winters. Many high-performance systems can operate efficiently at temperatures as low as -25°C to -30°C. However, efficiency does drop in extreme cold, which is why proper sizing and installation matter.
To maximize reliability:
- Choose a cold-climate heat pump – Standard models lose efficiency below freezing, but modern units with variable-speed compressors adjust to outdoor conditions for consistent performance.
- Consider backup heating – In extreme cold, a secondary heat source, such as an electric resistance coil or a high-efficiency gas furnace, can provide additional warmth.
- Ensure proper installation – A well-installed heat pump includes the right defrost cycles and drainage solutions to prevent ice buildup in winter.
Can a heat pump replace a furnace or central AC?
A heat pump can fully replace both a furnace and air conditioner in many Ontario homes. However, suitability depends on insulation levels, home size, and heating demands. We recommend always having a supplementary heat source for extreme cold weather events.
Replacing a furnace
In well-insulated, airtight homes, a heat pump can handle heating needs year-round. In older homes with higher heat loss, a hybrid system—pairing a heat pump with a supplementary gas/oil/propane or electric component — offers a balance of efficiency and reliability. During really cold spells, the furnace can kick in to provide additional heat, which means that heat pumps don’t have to work really hard and consume more electricity.
Replacing central heating and air conditioning
The benefits of heat pumps do not need to be realized with ‘stand-alone’ units (ductless head units). Homes with existing ductwork can easily switch from central heat and AC to a heat pump without major modifications.
Cost savings and energy efficiency
The upfront cost of a heat pump can be higher than a traditional furnace or air conditioner, but long-term savings will make up for it. Because heat pumps move heat rather than generate it, they use less energy than gas, oil, or electric resistance heating. When considering heat pumps, consider the current cost (or projected cost) of traditional heating methods for your home. As you might expect, DeCarli Contractors will recommend making use of heat pumps when it makes sense to do so.
Key cost benefits:
- Lower energy bills – Heat pumps can reduce heating costs by 30% to 50% compared to electric baseboards or oil heating.
- Incentives and rebates – Ontario offers rebates for energy-efficient home upgrades, including heat pumps, making installation more affordable.
- Reduced fuel dependency – A fully electric system eliminates the need for natural gas, oil, or propane, reducing exposure to fluctuating fuel prices.
For homeowners switching from electric resistance heating, the savings are even more significant. Heat pumps provide the same warmth at a fraction of the electricity cost. Compared to propane-fuelled systems, savings are also significant.
How to use a heat pump efficiently
Getting the most from a heat pump isn’t just about installation—it’s about how you use it. Heat pumps operate differently than furnaces, and small adjustments can make a big difference in comfort and efficiency.
Optimal settings for winter
- Set it and leave it – Heat pumps work best with consistent temperature settings. Frequent adjustments force the system to work harder.
- Use smart controls – A smart thermostat designed for heat pumps helps maintain efficiency by optimizing temperature adjustments.
- Supplement with ceiling fans – Running ceiling fans on low in reverse helps distribute warm air evenly.
Optimal settings for summer
- Use the dehumidification feature – Many heat pumps offer a dry mode that removes humidity without overcooling, improving comfort and efficiency.
- Close blinds during peak sun hours – Reducing heat gain in summer helps your heat pump cool more efficiently.
Installation considerations for new builds and retrofits
For new construction, integrating a heat pump system from the design stage allows for the most efficient setup. Well-sealed building envelopes, high-performance insulation, and proper duct design ensure that a heat pump operates at peak efficiency.
For existing homes, a retrofit may require duct modifications, additional electrical capacity, or strategic placement of outdoor units. In colder climates, choosing a model with a high HSPF (Heating Seasonal Performance Factor) ensures better winter performance.
Is a heat pump the right choice for your home?
Heat pumps are an excellent choice for many Ontario homes, offering energy-efficient heating and cooling in one system. Whether a heat pump can fully replace a furnace depends on home insulation, local climate conditions, and personal preferences. A hybrid setup—combining a heat pump with a backup furnace—offers the best of both worlds in colder regions.
At DeCarli Contractors, we take a building-first approach to choosing heat pumps. We ensure that homes are properly insulated, airtight and designed for long-term energy efficiency, then recommend the best options for your situation. Whether you’re considering a heat pump as part of a new build or upgrading your existing heating/cooling system during renovation, we can help you make the right choice for comfort and savings.
We would welcome the chance to discuss your building plans. Please get in touch at your convenience.
