Drain Water Heat Recovery: Could It Benefit Your Workplace?
Heating of water for use in your workplace is going to account for a significant percentage of your monthly energy expenditures. If your business is one that uses a substantial amount of hot water –restaurants, food or beverage producers, or certain types of manufacturing facilities, for example –your water heating costs will be dramatically higher. Business owners who want to get better efficiency from their hot water usage can benefit from installing a drain water heat recovery system.
Once hot water is used, it is usually removed through your building’s drainage system. Granted, at that point it has served its purpose, but there is still heat energy in that water — as much as 90 percent of the heat energy that has already been paid for is lost. A drain water heat recovery system is designed to capture and recycle large amounts of that heat before the water gets away.
What drain water heat recovery does
A drain water heat recovery system is designed to recover heat and use it to warm up cold water flowing into your water heater or that is being directed to other plumbing fixtures throughout your commercial or industrial building. These systems are a practical energy-saving solution that works with all kinds of water heaters, but are especially effective with tankless (on-demand) and solar water heaters. Drain water heat recovery systems work best if they have a tank for storing warmed water.
Appliances that use a lot of water, such as dishwashers and clothes washers, are almost certain to require a storage-type system to be effective. Systems without storage tanks will only be effective when both hot water and cold water are running at the same time, such as during a shower or bath. Unfortunately, this severely limits the amount of benefit you can get from using a drain water heat recovery system. You can use this equipment to recover heat from any type of appliance or hot-water drainage system. If your business uses large amounts of hot water, you’ll be able to recover the majority of that heat to use again. This will save substantial amounts on your regular water heating expenses. How drain water heat recovery works
Storage-type systems: In heat recovery systems that use storage tanks, the unit maintains a separate tank full of clean water that will be heated by recovered energy from the drain water. As drain water exits your facility, it flows through a spiral-shaped tube at the bottom of the heat recovery and storage tank. As water is warmed, it rises to the top of tank. Water that is headed to the main water heating unit is warmed and preheated as it flows through a coil in the top portion of the tank.
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Non-storage tanks typically have a copper heat exchanger placed vertically in a section of the major drain system. A copper tube is wrapped very closely around this heat exchanger. Incoming cool water flows through this spiral tube as hot drain water flows down the drain pipe. The heat exchanger transfers heat to the incoming cold water, recapturing heat energy before it is lost. Drain water heat recovery systems are designed to keep the two water sources separate. The hot and possibly contaminated drain water never mingles with the clean water intended to be heated and used within your facility. Make sure these types of energy recycling systems are installed and maintained by a qualified professional plumber to ensure proper operation and water cleanliness.
Our goal is to help educate our customers about Plumbing, HVACR, Fire Protection, and Alarm Systems in Mechanical, Commercial, and Residential settings. For more information on drain water heat recovery and how it can help you conserve energy and save money on your water heating bills, or to view projects we’ve worked on, visit our website!
Image Credit: www.nrcan.gc.ca
