Improve Your Energy EFficiency With a Commercial Heat Pump Installation
As the world comes to grips with the realities of climate change, groups in various industries have altered the way they operate to reflect the issue. One major area in which this can be seen is the electrification of buildings, particularly in cities such as New York City, where climate regulations are becoming increasingly stringent. Unfortunately, this often leaves building owners struggling to determine how to comply with limitations on factors like energy usage and greenhouse gas emissions set by climate legislation. Fortunately, some measures can help improve energy efficiency in urban facilities. One such recourse is heat pumps.
Heat pumps are a form of HVAC equipment that transfer heat from warmer to cooler spaces. They can be used for both heating and cooling purposes. Heat pumps draw heat from outside during the heating season and move it into the facility to provide heating. Heat pumps move heat from the facility to the outside during the cooling season. One factor that sets heat pumps apart from other HVAC equipment in the shift towards environmentalism is that heat pumps are powered by electricity as opposed to fossil fuels, allowing them to be more environmentally friendly. These facts make heat pumps an appealing alternative to other HVAC systems.
So how can you determine whether a commercial heat pump installation to provide heating and cooling to your facility is right for you? Below we give some background information on heat pumps, including how they work, components of a heat pump system, and important factors to consider.
How Heat Pumps Work
Heat pumps do not generate heat, meaning they do not require fuel combustion. This makes heat pumps more efficient than boilers, which can never convert 100% of the fuel they burn into usable heat. Additionally, heat pumps do not need to consume watts to produce heat like electric resistance heaters, which can operate at 100% efficiency. Rather, they move heat from one space to another. As a result, heat pumps can provide about four times more thermal energy than the amount of electrical energy required to power the equipment (400% efficiency; Coefficient of Performance (COP) of 4). This means the heat pump uses 1 kW of electricity to provide 4 kW of heating. (Note: Heat pump COP may vary by heat pump type and environmental conditions.)
Heat pumps can vary in terms of their thermal source/sink. Air-source heat pumps transfer heat between indoor air and outdoor air. Ground-source heat pumps (i.e., geothermal heat pumps) transfer heat between indoor air and the ground. A common type of geothermal heat pump, known as a water-source heat pump, transfers heat between indoor air and water. Heat pumps consist of outdoor and indoor components. Heat is transferred between the outdoor and indoor components by a refrigerant that circulates between the two elements. In cooling mode, heat is absorbed from indoors and released outdoors. In heating mode, heat is absorbed from outdoors and transferred indoors.
Though ground-source heat pumps require a more intensive and costly installation process, they cost less to operate because they utilize heat from the ground or water, which remain at relatively constant temperatures throughout the year. Even when outside temperatures are low, all heat pumps (including air-source heat pumps) can absorb heat from the outside to release it indoors. This is because the refrigerants used by the heat pump system to transfer heat have very low boiling points. This means that even at low temperatures, the refrigerant can boil and carry thermal energy from the outdoors into the facility.
Components of Heat Pump Systems
Heat pumps require some basic components to function. An outdoor unit contains a coil that switches functions depending on whether the heat pump is in heating or cooling mode. In heating mode, the coil acts as an evaporator, boiling the refrigerant (i.e., turning the refrigerant from liquid to gas) as it absorbs heat from outside. In cooling mode, the coil acts as a condenser, condensing the refrigerant (i.e., turning the refrigerant from gas to liquid form) as it releases heat to the outside.
The indoor unit also contains a coil which, like that for the outdoor unit, changes functions based on the mode the heat pump is in. In heating mode, the coil acts as a condenser, condensing the refrigerant as it releases heat to the indoors. In cooling mode, the coil acts as an evaporator, boiling the refrigerant as it absorbs heat from the inside air.
The coils in the outdoor unit contain a refrigerant. The properties of the refrigerant (i.e., boiling point) determine how heat is transferred between outside and inside. A compressor is used to pressurize the refrigerant. A reversing valve changes the direction of refrigerant flow in the system, allowing the system to shift between the heating and cooling modes. An expansion valve regulates the flow of the refrigerant through the system.
Heat pump systems have the potential to reduce a facility’s fuel usage and greenhouse gas emissions. In addition, continued developments of heat pump technologies lead to improvements in efficiency and cost-effectiveness, further encouraging their adoption in the marketplace.
While heat pumps are a useful tool in decarbonization efforts, some drawbacks accompany their use. This includes the high up-front costs and significant amounts of research and design work needed prior to installation. Additionally, there are some concerns regarding the negative environmental impacts of the refrigerants used in heat pump systems. For example, the leakage of refrigerant gasses is linked to ozone depletion, which contributes to global warming.
Although heat pumps can transfer heat from the cold outside air to provide heating, they typically work better in warmer regions. Heat pumps can be used in conjunction with other heat sources in colder climates when temperatures are low. On especially cold days when temperatures drop too low to allow the heat pump system to operate effectively, the other heat source may be used instead. This is often referred to as a dual fuel system.
Water-source heat pumps require the system to have access to a lake or river. There are two types of water-source heat pumps: open-loop and closed-loop. The open-loop configuration takes in water from the source, uses it in the system, and releases the water back into the source at a different location than the point of intake. Meanwhile, the closed-loop configuration uses a mixture of water and antifreeze to capture heat. Water-source heat pumps are more efficient than air-source and ground-source heat pumps and can be easier and cheaper to install than ground-source. However, there are usually strict permissions associated with water-source heat pump systems, as leaks in the system could result in negative environmental effects due to the nature of the chemicals used for the refrigerant and antifreeze. Leaks can cause harm to the wildlife in the areas surrounding the bodies of water used for the heat pumps.Environ Energy has experience with various parts of the heat pump system installation process. We can identify solutions to help you finance heat pump system installation or work with other firms to implement a heat pump system within your facility. To find out how Environ can help incorporate heat pumps into your facility’s HVAC system, give us a call or fill out our contact form.