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HVAC - Introduction to Heat Pumps

In this module, we take an introductive look at air-source heat pumps in HVAC systems and how they move heat. Their benefits and energy efficiency advantages are discussed, as well as best practices for determining ideal sizing and design for installation. Lastly, calculations are detailed in order to know how to make a financial case for the purchase and installation of efficient air-sourced heat pumps. 

Curriculum

  1. Remember

    • Describe what an air source heat pump is and what it can be used for.
    • Remember key terms related to sizing and design of heat pumps.
    • Know the customer benefits of ASHPs.

  2. Understand

    • Understand how a heat pump moves heat.
    • Understand the different types of heat pumps.
    • What are the different heat pump options when looking for alternatives for homes that are currently heated by a gas furnace or boiler?
    • Understand the market trends for heat pumps and the benefits of switching to heat pumps in existing homes.
    • Understand the business case for ASHP installation services.

  3. Apply

    • What should a person consider before installing an air source heat pump?
    • What should an HVAC installer consider about the ductwork and condensate drain in an existing home before installing a heat pump?
    • Be able to compare the operating costs of ASHPs and fossil fuel heating systems.

Teaching Materials

HVAC Geothermal Heat Pumps

A ground-source heat pump is an electric heat pump that exchanges heat with the ground or groundwater. Ground source heat pumps (often called geothermal heat pumps) take advantage of the fact that the temperature of the earth (below the surface) remains fairly constant.

The average single-family home spends half of its energy use on heating and cooling. Because heat is exchanged with the ground rather than with the outside air, which has more erratic temperatures, ground-source heat pumps are a very efficient source of heating and cooling year-round. These pumps can have efficiencies of 300% to 600%, compared to 175% to 250% for central ducted air-source heat pumps.

A geothermal heat pump exchanges heat with the earth via a system of pipes called a loop, which is buried in the ground (or sometimes, in a pond). Water or a mixture of water and antifreeze circulates through the pipes, exchanging heat with the earth. In winter, heat moves from the ground into the heat exchanger and into the home; in summer, the process is reversed, and heat is released from indoor air into the heat exchanger and ultimately, back into the ground. This heat can also be used to heat domestic water.