Sorry, No Tanks: A Brief Introduction to Tankless Water Heaters

Aug. 30, 2012 — With co-op boards and condo associations constantly on the lookout for money savings and energy conservation — which often amount to the same thing — many boards are wondering if they should install a relatively new technology known as "tankless" water heaters. What are they, and do they really provide energy savings?

Tankless water heaters work by heating water with either a gas burner or an electric element, and delivering water as a constant supply. Heat loss is effectively avoided because of the instantaneous nature of the system. But here comes problem No. 1: The flow rate of hot water can decrease as demand increases.

Indeed, tankless water heaters — which are being marketed to smaller co-ops and condos in addition to their primary user, owners of single-family homes — seem at first glance to be a big plus: They are, on average, 24 to 34 percent more efficient than traditional heaters. They require less energy and last twice as long as their more conventional counterparts. They can also run on electricity, gas, propane, or solar power.