Heat pumps are good alternatives to furnaces and air conditioners in areas with moderate heating and cooling needs. Heat pumps work like refrigerators in that they use electricity to transfer heat from a cool space to a warm space. In heating seasons, heat pumps transfer heat from the cool outdoor environment into the warmth of the house. During cooling seasons, heat pumps transfer heat from the house to the outdoor air.
Since heat pumps move heat rather than generate it, they tend to use a quarter of the operation cost of conventional heating or cooling appliances.
Types of Heat Pumps
There are three main types of heat pumps:
- Air-source heat pumps: This type of heat pump provides efficient heating and cooling by moving heat from your house to the outdoors and vice versa. This heat pump can deliver up to three times more heat energy compared to the electrical energy it consumes. Air-source heat pumps are able to do this because they simply move heat and not convert it like in combustion heating systems.
- Ductless, mini-split heat pumps: These heat pumps are air-source heat pumps that are ductless. They are ideal for houses with non-ducted heating systems such as those that use space heaters, hydronic and radiant panels.
- Absorption heat pumps: These pumps work like air-source heat pumps. The only difference is that they are not driven by electricity, but by a heat source like propane, natural gas or solar-heated water.
- Geothermal heat pumps: These pumps are also referred to as GeoExchange, ground-source or water-source heat pumps. These pumps utilize the earth’s constant temperature in place of the outdoor air temperature.
The most common type of heat pump is the air-source heat pump (ASHP). It can reduce up to 50% electric use compared to electric-resistance heating appliances such as baseboard heaters and furnaces. For every 1kW of electric energy utilized, the air-source heat pump typically generates around 3kW of thermal energy. This translates to an effective efficiency of 300%, but since it is thermodynamically impossible for the effective efficiency to go beyond 100%, energy performance is usually expressed as a coefficient of performance (CoP). In this case, the CoP is three.
For heat pumps, the energy produced is more than the energy consumed because only the electric energy is used to drive the compressor as well as the circulating pumps. The remaining energy is usually moved from heat sources like the outdoor air, rivers or the ground.
Different Types of Coefficient Performance
There are different types of coefficient performance measurements, including:
- Seasonal Coefficient of Performance (SCoP): This measure is usually used with air-source heat pumps. It gives the measure of the heat pump performance over a year. It also factors in the varying air temperature.
- Seasonal Energy Efficiency Ratio (SEER): This coefficient performance measure is also used in air-source heat pumps, and it measures the cooling performance of the heat pump in a year.
- Energy Efficiency Ratio (EER): This measure takes into account the ratio of the delivered thermal energy to the total electrical power. It also factors in the performance of controls, fans and pumps.
- Seasonal Performance Factor (SPF): This coefficient performance measures the ratio of total thermal energy delivered over the year to the total electrical consumption. Of all the coefficient performance measurements, it is considered the most useful.
Comparison of Efficiency With Other Appliances
As we had seen earlier, the efficiency of an air-source heat pump is at 300%. To show how efficient it is, let’s compare its efficiency to that of other appliances:
- Direct electrical heating has a 34% to 45% efficiency
- Conventional gas/oil boiler has a 70% to 80% efficiency
- Condensing gas/oil boiler has a 90% to 96% efficiency
Advantages of Heat Pumps
Heat pumps are gaining popularity due to their affordability and energy efficiency. Some of the advantages of heat pumps include:
- Lower running costs: Heat pumps are cheaper to run because they pump heat from one space to another. Pumping heat uses less electricity compared to converting it. Energy-efficient systems provide long-term savings on energy.
- Low maintenance costs: Compared to combustion heating systems, heat pumps require less maintenance. Heat pumps require routine checks once a year, which you can do yourself. Professional routine checks are required after every three to five years.
- Long life span: The average life span of heat pumps is between 14 to 15 years. Some can last up to 50 years.
- Reduced carbon emissions: Heat pumps are environmentally friendly because they reduce carbon emissions through their efficient conversion rate.
- Provide cooling in warm weather: Heat pumps reverse their actions during warm weather. They function as air conditioning units.
- Safety: Heat pumps are known to be safer than combustion-based heating systems.
Disadvantages of Heat Pumps
- Large up-front cost: Heat pumps require high up-front costs, which could discourage many consumers.
- Require professional installation: Installing heat pumps requires extensive research so as to understand the local geology, heat movement and the heating and cooling needs of the household it will be installed in.
- Installation process may take time: Installing heat pumps requires a significant amount of work that may disrupt your household for an extended time.
- Cold weather damages: Some heat pumps may be affected by cold weather, which can lead to damages. In this case, heat pump efficiency may be disrupted during cold seasons.
- Planning permissions: Depending on where you live, you may be required to get special planning permission to install a heat pump.
Future Developments That Will Help Improve the Effectiveness of Heat Pumps
With the growing popularity of heat pumps, manufacturers are looking into developing heat pumps that are more compact and have high efficiency in order to reduce the operating and maintenance costs further. Some of these developments include:
- Use of natural gas or waste heat in place of refrigerant gases to deliver higher temperatures. Since these pumps can be connected to a gas source, they are ideal for older buildings with hydronic heating systems.
- Use of highly efficient compressors such as the two-speed compressors, which improve the heat pump’s heating or cooling capacity. These compressors help save electrical energy while reducing compressor wear.
- Use of dual-speed motors in some models. These variable-speed controls found on the outdoor or indoor fans allow air to move freely, reducing cool drafts but improving electrical savings.
- Use of a desuperheater, which works to recover waste heat from the cooling mode of the heat pump. This heat is then channeled to heat water with an efficiency that is two to three times more than an electric water heater.
- Use of electric resistance heaters to work as a backup in cold weather. Burners can be installed on the heat pumps to improve their efficiency.
Contact Summit Heating & AC Today!
After reading all this information about heat pumps and their energy efficiency, you may want to call in a professional to get the work done. Look no further. At Summit Heating & AC, we are here to help. Our top-notch team will handle all your heating and cooling needs. Whether you want a first-time installation or seasonal maintenance, we can get it done. We serve the whole of Denver, CO, area with our 20-year experience. So, waste no time, and give us a call today.