Tankless Water Heaters

Heating and storing water in a conventional water heater takes lots of energy, which translates into higher utility bills. If you're looking to reduce the amount of energy used to heat your water, consider a tankless water heater. Tankless water heaters heat and deliver water on demand, without storing it. Rather than holding water in a tank, they circulate it through a series of burners or electric coils that heat the water as it passes through.

Though tankless units cost more than most conventional water heaters, they're cheaper to operate because energy isn't required to maintain a large tank of hot water 24 hours a day. Also, because the water heater doesn't store hot water, it never runs out--unless, that is, the flow surpasses the unit's ability to heat it. If two people take separate showers at the same time, a tankless unit may not be able to handle the flow. To overcome this problem, you can install a "whole house" type tankless water heater or install two or more tankless water heaters, connected in parallel for simultaneous demands of hot water. This approach may be more appropriate in a townhouse or a brownstone, which may have more space (say, in a basement) for larger or multiple units. You can also install separate Tankless Water Heaters for appliances—such as a clothes washer or dishwater—that use a lot of hot water in your home. This approach may be more appropriate to a condominium, where there may not be a large utility area and smaller units make more sense.

Because of the heat output and response time required, most (but not all) whole-house tankless heaters are gas-fired (including propane and kerosene). Smaller, single-fixture units, which may store a few gallons of water, are usually electric. A company based in Canada, Pulsar Advanced Technologies, is set to release the Vulcanus MK4, a water heater that uses microwave technology to heat water on demand. The unit can heat water from 35 degrees Fahrenheit to 140 degrees Fahrenheit in seconds and can provide hot water for multiple applications at once.

This technology is most appropriate for single-family homes or condos in small buildings where each unit has its own water-heating system. In buildings where multiple units share a heating system, the money and materials involved with taking a single apartment off the central system may be prohibitive, if it is allowed at all.