How Low Can a Heat Pump Go?

Heat pumps are gaining in popularity as a viable alternative to conventional HVAC systems. They allow home heating and cooling with far less energy use than older types of environmental systems.

Heat Pump Basics

Heat pumps use electricity to move heat from one area to another – from outside to inside during cold times and inside to outside during hot periods. They are able to heat and cool homes with little energy expenditure, because they do not create heat or cold, only move it.

There is a downside to heat pumps. They are not effective enough to use in climates where the temperature drops to, and stays, well below zero. There simply is not enough heat for them to work with outside to increase temperatures inside to comfortable levels.

Types of Pumps and Temperature Effectiveness

Some types of heat pumps are better able to handle cold temperatures than others are. Heat pumps come in three main types:

  • Air-source heat pumps are the most common type in use today. These pumps draw heat from the air surrounding them. When optimized for cold temperatures, they maintain their full heating effect down to 41° degrees Fahrenheit and can still produce heat at 60 percent effectiveness at 17° degrees.
  • Water-source heat pumps draw heat from water and can work at lower temperatures than air-source pumps. They are able to keep functioning at lower temperatures because the pipes used to extract heat are laid at the bottom of a body of water where it is somewhat insulated.
  • Geothermal-heat pumps are set into the ground at a depth that maintains a relatively steady temperature all year. This allows them to function in all but the absolute coldest conditions, but also makes them more expensive to install than other types of pumps.

While these are the three main types of heat-pump systems, there are other, newer models:

  • Absorption heat pumps. These pumps use heat as an energy source rather than electricity. This heat can be derived in many ways – solar-heated water, burning propane or natural gas, or geothermal-heated water. Depending upon the pump’s specific heat source, they can continue working in a range of cold temperatures.
  • Hybrid heat-pump systems. Hybrid systems combine two types of heat pumps into one HVAC system. Most often, these systems combine air-source heat pumps and geothermal-heat pumps. A hybrid system will use the more energy-efficient air source pump until the temperature drops to a point where it loses effectiveness, and then the geothermal pump will begin providing heat. These systems can work in any temperature at which a geothermal pump would function, but they are cheaper to operate. The initial cost of installing a hybrid heat pump system, though, is very high.

Heat-pump technology is making these systems cheaper, more effective, and better able to withstand extremely cold temperatures. More people are acknowledging the benefits heat pumps have over traditional HVAC systems and are switching to these newer, more energy-efficient heating and cooling systems. For more information on heat pumps, call the HVAC experts at J&M Air Conditioning and Heating.