This paper looks at different types of air-source heat pumps used in cold Canadian winters. The main goal was to see how well these heat pumps work in extreme cold conditions. They compared three types of heat pumps: standard ones, cold-climate models, and burner-assisted ones. Each type has to be very efficient, use less power, defrost properly, and last a long time to be good for customers and power companies. The study found that different types of heat pumps have strengths and weaknesses when it comes to heating spaces during cold weather.