Why Buy an Energy-Efficient Heat Pump?

If you use electricity to heat your home, consider installing an energy-efficient heat pump system. Heat pumps are the most efficient form of electric heating in mild to moderate climates, providing two to three times more heating energy than the equivalent amount of electricity they consume.

Air source heat pumps are recommended for mild and moderate climate regions, where the winter temperatures usually remain above 30°F.

Ground-source (also known as geothermal) heat pumps are more efficient and economical to operate compared to conventional air-source heat pumps, especially in climates with similar heating and cooling loads.

About Heat Pump Efficiency

Three types of heat pumps are typically available for residential use: (1) air-to-air, (2) water-source, and (3) ground-source. Heat pumps collect heat from the air, water, or ground outside your home and concentrate it for use inside. Heat pumps operate in reverse to cool your home by collecting the heat inside your house and effectively pumping it outside.

Heat pumps have both heating and cooling ratings, both in terms of capacity and efficiency. Capacity ratings are generally in British thermal units (Btu) per hour or tons (one ton equals 12,000 Btu/hr).

Heating efficiency for air-source heat pumps is indicated by the heating season performance factor (HSPF). The HSPF tells you the ratio of the seasonal heating output in Btu’s divided by the seasonal power consumption in Watt-hours. A heat pump can supply 2 to 3 times as much heat as it consumes in electricity because it moves energy from outside to inside (or vice versa).

The efficiency of a heat pump varies with the outdoor temperature. The performance of an air source heat pump in heating mode decreases as the outside air temperature drops. The actual seasonal efficiency (as opposed to the rating) is, therefore, higher in a mild climate than in a severe cold climate.

In cooling mode, a heat pump operates similarly to a central air conditioning system. The seasonal energy efficiency ratio (SEER) is analogous to the Heating Seasonal Performance Factor (HSPF), but it measures the seasonal cooling performance.

Tips for Buying a New Heat Pump

Proper Sizing and Installation

You must size and install heat pumps properly for efficient operation. Contractors typically size heat pumps for either heating demand or cooling demand, depending on which requires the larger unit (almost always cooling).

However, heat pumps don’t perform well during extended periods of sub-freezing temperatures. Meeting all your heating needs with an air-source heat pump may not prove cost-effective in frigid climates.

Ground-Source vs. Air-Source Heat Pumps

Ground-source heat pumps (GSHPs) operate more efficiently and quietly than conventional air-source heat pumps. Although heat pump installation costs more for GSHPs, the dramatic efficiency improvements can yield attractive life-cycle cost savings.

The suitability of a GSHP depends on your lot size, subsoil conditions, and landscape. Summer cooling and winter heating requirements also affect this decision.

Performance Ratings and Features

Choose Higher HSPF Ratings

Select a heat pump with a higher Heating Seasonal Performance Factor (HSPF). For units with comparable HSPF ratings, check their steady-state rating at -8.3°C, the low-temperature setting.

The unit with the higher rating will operate more efficiently in cold conditions.

Demand-Defrost Control

Choose a heat pump with demand-defrost control. This feature minimizes defrost cycles, reducing supplementary and heat pump energy use.

Sound Ratings

Select a heat pump with an outdoor sound rating of 7.6 bels or lower. Lower values mean quieter outdoor unit operation.

Ductwork and Installation Considerations

Ductwork Requirements

Installing a heat pump in an existing home without an existing heating system or air conditioner may require enlarging the ductwork. Heat pump systems generally need larger duct sizes than other central heating systems.

For proper heat pump operation, airflow should reach 50 to 60 liters per second per kilowatt-hour or 400 to 500 cubic feet per minute per ton of cooling capacity.

Integration with Electric Furnaces

When adding a heat pump to an electric furnace, position the heat pump coil on the cold (upstream) side of the stove. This positioning provides the most excellent efficiency.

Noise Control

Fans and compressors generate noise during operation. Locate the outdoor unit away from windows and adjacent buildings.

Some units also create noise when they vibrate. You can reduce this noise by selecting quiet equipment or mounting the unit on a noise-absorbing base.

Tips for Lowering Your Heat Pump’s Energy Usage

Thermostat Management

Avoid Manual Setbacks

Don’t manually set back a heat pump’s thermostat at night. Without a thermostat specifically designed for heat pump setback, the electric resistance backup heat will engage when you raise the thermostat in the morning.

This results in significantly higher energy consumption compared to maintaining a consistent temperature.

Regular Maintenance Tasks

Filter and System Maintenance

Clean or replace filters monthly or as needed. Maintain the system according to the manufacturer’s instructions.

Filter and coil maintenance dramatically impacts system performance and service life. Professional heat pump maintenance ensures optimal operation and performance.

Dirty filters, coils, and fans reduce airflow through the system, which can lead to decreased efficiency and increased energy consumption. Reduced airflow decreases system performance and can lead to compressor damage if it continues for extended periods.

Annual Fan Motor Care

Clean and lubricate the fan motor annually to ensure proper airflow for optimal operation. Check the fan speed simultaneously.

Incorrect pulley settings, loose fan belts, or incorrect motor speeds all contribute to poor performance. Regular heat pump tune-ups address these issues.

Outdoor Unit Protection

Wind Considerations

Protect outdoor units from high winds, as they can reduce efficiency by causing defrost problems. However, avoid placing outdoor units in restricted areas that could cause air recirculation over the coil.

Proper placement ensures optimal performance and prevents the need for frequent heat pump repair.

Consider replacing your current system with a heat pump if it frequently requires repairs or operates inefficiently. You might also consider converting a gas furnace to a heat pump for improved efficiency and environmental benefits.