Retrofitting an air source heat pump (ASHP) in an older home is an effective way to improve energy efficiency, reduce heating costs, and increase comfort. However, installing a heat pump in a house that wasn’t originally designed for it presents unique challenges. With proper planning and modifications, older homes can reap the benefits of modern HVAC technology. Here’s a step-by-step guide on how to retrofit an air source heat pump from heat pump supplier in an older home.

1. Assess the Home's Insulation and Energy Efficiency

Before installing an ASHP, it's crucial to assess the home’s insulation and overall energy efficiency. Older homes, especially those built before modern insulation standards, tend to have significant heat loss.

• Insulation Upgrade: Start by improving insulation in key areas like attics, walls, and basements. Proper insulation minimizes heat loss, which helps the heat pump operate more efficiently.
• Seal Gaps and Leaks: Check windows, doors, and other openings for air leaks. Sealing these gaps will improve the efficiency of the heat pump and prevent drafts, creating a more comfortable indoor environment.

2. Size the Heat Pump Correctly

Sizing the ASHP to fit the home’s heating and cooling needs is essential for its efficiency and performance. Inadequate sizing can lead to inefficient operation and higher energy bills.

• Manual J Load Calculation: A professional HVAC technician can perform a Manual J load calculation to determine the correct size of the heat pump based on the home’s square footage, insulation levels, and climate zone.
• Consider Heating Needs: Older homes may require a more powerful system to compensate for poor insulation or inefficient heating systems. Ensure that the chosen ASHP can handle the specific needs of the home’s heating and cooling load.

3. Address Ductwork and Distribution System

Most older homes were designed with traditional heating methods like forced-air furnaces or radiators, meaning the existing ductwork may not be compatible with an ASHP.

• Evaluate Ductwork: Inspect the existing duct system for leaks, size, and condition. Ducts in older homes may be undersized or poorly sealed, which can hinder the efficiency of the heat pump.
• Upgrade or Repair Ducts: If necessary, upgrade or replace ducts to ensure that air flows efficiently throughout the home. Properly sized and sealed ducts improve system performance and comfort.
• Consider Ductless Options: In some cases, particularly in homes without existing ductwork, a ductless mini-split ASHP system can be a better solution. This option uses individual units to heat or cool specific rooms and avoids the need for extensive ductwork.

4. Install the Indoor and Outdoor Units

The installation process involves placing both the indoor and outdoor components of the heat pump system.

• Outdoor Unit Placement: The outdoor unit should be installed in a location that allows for proper airflow, typically on a flat, level surface away from obstructions like trees or fences. Ensure there is enough space for maintenance and service.
• Indoor Unit Installation: The indoor air handler should be positioned for optimal air distribution. It’s essential to consider room layout and airflow when placing the unit. A central location in the home ensures more even heating and cooling.

5. Consider the Electrical System

Air source heat pumps require a dedicated electrical circuit for safe operation. Older homes may need electrical upgrades to accommodate the power demands of the new system.

• Electrical Panel Inspection: Have an electrician assess your home’s electrical panel to ensure it can handle the increased load. Older electrical panels may need to be upgraded to meet the heat pump’s requirements.
• Thermostat Upgrade: Modern heat pumps work best with a digital or smart thermostat. Installing an upgraded thermostat will improve the system's efficiency by providing better control over temperature settings and reducing energy consumption.

6. Professional Installation and Commissioning

While retrofitting a heat pump in an older home can be a DIY-friendly project for the experienced, it is recommended to hire a qualified HVAC contractor for the installation. A professional ensures that the system is properly sized, installed, and calibrated for optimal performance. They can also address any technical challenges, such as ductwork modifications or electrical upgrades, and guarantee the system runs efficiently.

Conclusion

Retrofitting an air source heat pump in an older home is a sustainable way to improve comfort, reduce energy costs, and increase efficiency. With proper planning—starting with upgrading insulation, evaluating ductwork, and sizing the system correctly—homeowners can enjoy the many benefits of modern heating and cooling technology. Whether you’re looking to replace an old system or make your home more energy-efficient, an ASHP retrofit is an excellent investment for the future.