What are heat pumps? 

Heat pumps offer cooling and heating by removing heat from the home in the summer and pulling heat into the home in the winter months.  They are an energy-efficient alternative to traditional furnaces and air conditioners with a lower carbon footprint.  By utilizing “staging” and “variable speeds” heat pumps have the ability to control your indoor temperature and humidity with consistency and comfort throughout the year in both hot and cold climates.

This page will provide background information on the types of heat pumps, assist with information to help individuals determine if a heat pump makes sense for them, provide additional resources on heat pump manufacturers, and links for programs offered by utilities.

Types of heat pumps:

Ducted Air-Source Heat Pump
Mini-Split Air-Source Heat Pump
Geothermal Heat Pump
Absorption Heat Pump
Absorption Heat Pumps

Ducted Air-Source Heat PumpsAir-source heat pumps, including ducted air-source heat pumps, transfer heat between your house and the outside air. According to the US Department of Energy, air-source heat pumps have the ability to reduce your electricity consumption by 50% compared to traditional resistance heating and can reach more than 200% efficiency compared to a gas furnace which at times can reach 95% efficiency. Air-source heat pumps have been deployed across the country in all climates, including regions that experience cold winters like Maine and Minnesota. Ducted air- source heat pumps will use existing ductwork in a home, or can use smaller air-handlers in what is referred to as a “compact ducted” system.  These systems can be both “traditional” in the sense of having an outdoor unit with an indoor air handler, or mini-split systems with the ducted air-handlers.  Single zone mini-splits also come in options that can utilize short ductwork to address smaller zones to fully ducted whole home systems that utilize existing ductwork for air distribution.

Mini-Split Air-Source Heat PumpsMini-Split air-source heat pumps (sometimes referred to as “ductless”), are typically inverter compressors or variable speed systems and offer a variety of indoor units in multi-zone or multi-split applications. These systems can provide comfort for single zones of a home to full home solutions creating multiple zones of comfort controlled by the homeowner.   Mini-split or non-ducted systems are great applications for homes that do not have ducts or need a better solution to provide comfort to areas of the home that are uncomfortable, new use spaces, or a means to provide comfort to part of the home vs operating a whole home.  These systems are generally easier to install than other types of space conditioning units. Installations that use no ducts gain efficiencies as they avoid the energy losses associated with ductwork which can account for up to 30% of energy loss in climate conditioning.  Multizone or Multi-Split systems provide the homeowner with options to have multiple zones of comfort with individual zone temperature settings. These system configurations can have up to 8 indoor units or zones operating from one outdoor unit.  However, costs of installing mini or multi-split systems can be higher than other systems and correct unit sizing is extremely important.

Geothermal Heat Pumps: Also known as ground-source heat pumps and/or water-source heat pumps, geothermal heat pumps transfer heat between your home and ground or water sources nearby. By taking advantage of nearby consistent ground or water temperatures, geothermal heat pumps can reduce energy use by 30%-60% while having low operating costs. However, upfront installation costs tend to be higher than other types of heat pumps. They can be used in a variety of climates and can be used in extreme climates, however the size of your lot, subsoil, and landscape may hinder installation of these types of heat pumps.

 

Absorption Heat Pumps: Absorption heat pumps use heat, such as combustion of natural gas, steam solar-heated water, air, or geothermal- heated water, as their energy source rather than electricity. These are typically used in industrial or commercial settings, but have been available for large residential homes.

Speeds of Heat Pumps:

The type of compressor used in heat pumps is the main difference discussed in this section. Single-stage heat pumps have two modes on or off. When turned on the compressor operates at full power (60 Hz) no matter the weather conditions. Dual-staged heat pumps are units that have three modes and run at either 100% power (60 Hz) or with reduced power or are off. Lastly, variable speed units can operate at more stages and typically with an inverter compressor can exceed 60 Hz well above 100 Hz to quickly meet temperature setpoint and modulate to partial load for extended periods between full power and completely off.

Costs associated with single-stage units is the lowest, but due to only having an on/off option they have shorter run cycles and do not provide great humidity control and more temperature fluctuation above and below setpoint is typical. Dual-staged have higher efficiency and can be run at full power during colder weather and reduced to a lower level of power during more mild days. Variable speed systems is the most expensive unit, but the efficiency ratings, air quality, and humidity control are all better. Instead of having only a few power options, variable speed systems operate by varying the compressor speed, amount of refrigerant flowing, and indoor fan speed based on the home cooling and heating needs providing a more precise temperature and lower cost of operation.

Is a Heat Pump Right for You?

Heat pumps deployment is on the rise across the globe. Here in the US, heat pump technology has become more popular and federal and state programs have been developed to assist with the growth in demand. However, while more efficient for both heating and cooling than traditional furnaces and air conditioners, there are a number of factors to consider when determining whether to update your HVAC system to one of these heat pumps.

Location and Climate:

Heat pumps are capable of meeting the entire home heating needs, however single or dual-speed systems will likely rely on electric resistance heating at temperatures below freezing which is the most expensive form of heating and puts the most strain on the electric grid when in this mode of operation. Variable speed systems offer greater opportunity for cold climate heating because the compressor is not limited to the 60 Hz.  However, variable speed heat pumps do not mean that all systems are cold climate capable.  Make sure you ask for a cold climate heat pump that are made with different compressors which some manufacturers can provide effective heat below-freezing temperatures without electric resistance.  Consumers should ask for manufacturers performance of heating (Btu) output at various temperatures when making decisions Depending on your climate you may need to choose different speeds (dual-staged or variable speed) or different types (geothermal or air-source) of units. As a result, if you live in a cooler part of the state that experiences harsher winters it may make more sense to install a variable speed air source unit. While someone living in a warmer climate that experiences less heating days may need a single-stage unit. You may also want to keep your current furnace and consider a retrofit to the furnace that converts to a heat pump providing full cooling and efficient heating with the confidence of a furnace backup or for choosing the most economical fuel heating option.

Costs:

Dependent on the type of your new heat pump unit as well as the size of your home, the upfront costs and operational costs can vary. Average costs of air-source heat pumps can range between $3000 and $5000 per unit with better performing units going higher. Mini-split units can cost between $1300 and $8000 for part home solutions to complex multiple zone systems approaching $25,000. Geothermal heat pumps are more expensive and can range from $10,000 to $30,000 depending on soil conditions, plot size, and other factors. While these numbers may be concerning at first, it is important to consider that replacing a traditional furnace and air conditioner can cost between $1000-$10,000 together. Additionally, there are programs that assist with the upfront costs associated with installing heat pumps. It is helpful to check with your utility provider to see if they are offering rebates or low-cost financing for HVAC replacement. Check the resources section below for links to utility HVAC incentive programs.

Your Home:

It is important to perform an energy audit of your home. This inspection of your home provides an analysis of energy flows and provides feedback on the energy efficiency of your house. Energy audits can help prioritize the energy efficiency needs to ensure installation of a heat pump makes the most sense from both energy savings and financial perspectives.

While air source heat pumps can work with most properties, you may not see the same efficiency benefits that you would have otherwise if your home has not been kept up to newer building code standards. In Texas, more than two thirds of homes are over 20 years old and may need additional upgrades like weather stripping, sealing ductwork or attic insulation to see the full benefit of heat pumps.

connect with us today

At SPEER, our sole purpose is to help you and your organization move toward a more energy-efficient end-state. Our team supports a robust member network with training, peer support, and advocacy. Join us!