Understanding the schedule for hot water, exhaust fans and lighting systems and matching system operation to building occupancy is the first step toward improving energy efficiency in commercial restrooms, according to an article in Highrisefacilities.com.
Restrooms in high-rise commercial buildings are often overlooked when it comes to energy savings, but there are a number of opportunities to reduce the energy used in these spaces.
Commercial restrooms tend to be overlit, so measuring the lighting levels with a light meter and comparing the levels against Illuminating Engineering Society standards will help determine whether or not some fixtures need to be delamped or shut off. Installing lighting controls and occupancy sensors can save between 47 percent and 60 percent of a restroom’s lighting energy costs. Settings on existing occupancy sensors can be adjusted to turn off within a minute or less of someone leaving an area, which can result in additional energy savings.
High-rise facilities that are between 15 and 20 years old are typically over-exhausted. Exhaust fans can be set on a timer or to an occupancy sensor so they are not working around the clock. Installing a variable frequency drive on existing fans, if feasible, can help bring fan operation down to current code requirements.
A smaller-demand, tank-style water heater with a large storage capacity can help to lessen demand from domestic hot water, and the energy needed to heat the tank can be reduced by installing a circulation pump to get hot water from the storage tank to the fixtures. Connecting the pump to the building’s control system will save even more energy because the pump won’t have to continually pull heat out of the tank. Tankless, instantaneous point-of-use water heaters installed under sinks are the most energy efficient; however, not all buildings have the electrical capacity required to power these types of water heaters.
Preconditioning commercial restrooms should not be needed because high-rise commercial restrooms are typically located in the center section of the building and heat gain and heat loss through outside walls is generally not an issue.
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