Commercial HVAC: Ten Energy-Saving Technologies
- Heating, ventilation and air conditioning (HVAC) accounts for a large percentage of building energy use.
- New HVAC technologies can save energy and reduce operating costs.
- Proper system upkeep and a well-maintained building envelope can optimize savings.
Though critical to occupant comfort and employee productivity, heating, ventilation and air conditioning systems (HVAC) use a significant amount of energy. In fact, HVAC systems account for more than half of the total energy consumption in commercial buildings, making them prime cost-saving opportunities. The 10 technologies that follow can help to reduce energy use while improving occupant comfort and indoor air quality:
- Demand controlled ventilation—combines carbon dioxide sensors with economizers to maintain air levels within an appropriate range while avoiding over ventilation, which wastes energy. Best applied to high-density occupancy facilities such as schools, auditoriums, and churches.
- Dedicated outdoor air systems—improve humidity control by conditioning outdoor makeup air separately from indoor return air. Removing moisture from the outside air reduces the load on the cooling system and allows for energy efficient sensible-only cooling with equipment like chilled beams.
- Displacement ventilation—uses a low velocity stream of fresh, moderately cold air at floor level to displace warmer stale air near the ceiling. No air is recirculated, improving indoor air quality. The higher supply air temperature and reduced fan power saves energy. Most effective in spaces with high occupancy.
- Electronic expansion valves (EXV)—replace thermostatic expansion valves (TXV). EXVs handle loads down to 5% efficiently (compared to 50% for TXVs), enable system diagnostics, and save up to 15%.
- Energy recovery ventilation (ERV)—captures energy from exhausted air and uses it to precondition (temperature and moisture) incoming makeup air. ERVs save energy by reducing heating and cooling system loads while maintaining comfortable indoor air levels.
- Desiccant dehumidification—absorbs moisture with a solid or liquid desiccant and then evaporates it using heat. The system saves energy by removing humidity and precooling makeup air, reducing air conditioning load.
- Micro channel heat exchangers—have gained increasing acceptance for HVAC applications. It offers much improved heat transfer and thermal performance. You can achieve higher heat transfer in the same volume of space.
- Chilled beam cooling—uses natural convection and heat transfer with water-cooled panels. Systems currently available typically require a dedicated outdoor air unit and a tight building envelope to manage humidity. Chilled beam systems produce cool air directly in a building space, reducing fan energy use. Best used in spaces with low-density occupancy such as hospital rooms and offices.
- Adjustable speed drives (ASD)—save energy by reducing motor speed to accommodate varying HVAC loads. One type of ASD is a variable-frequency drive (VFD). A motor with a built-in VFD is known as an electronically commutated motor (ECM).
- Variable refrigerant flow (VRF) systems—are ductless systems that are highly flexible in capacity and design. These systems transport refrigerant instead of air or water, provide zoned temperature control, and save energy while ensuring occupant comfort.
While these technologies can provide significant cost savings, they are not appropriate for every situation. Consult with a trusted contractor about whether they are right for your application.
Maintenance practices are important for optimizing system efficiency. Have your HVAC equipment cleaned and inspected regularly by a qualified technician. To reduce energy losses, check for building envelope air leaks and make sure your facility is well-insulated.
By combining new technology with some old-fashioned attention to detail, you can cut costs and make your facility more comfortable.
Your electric utility offers incentives for purchasing energy efficient cooling equipment. For more information, see our Save@Work section.
This article has been prepared solely for the purpose of providing helpful information to users of this service. The information has been compiled by Questline, a contractor to the NHSaves utilities; however, no representation is made by either Questline or NHSaves as to the completeness or accuracy of the information contained therein. In particular, some information may be incomplete, may contain errors or may be out of date. In addition, neither Questline nor NHSaves endorses any product or service mentioned therein.