Whether building a new home or replacing a worn out appliance, a staggering array of water heater technology is available for modern households. Water heater selection may seem like the dullest of tasks, but choose wisely and you can see tremendous energy savings. Because there are so many factors involved, including size, efficiency, fuel, and the expenses of both the equipment and energy source, some careful research will be helpful.
Water heaters are fall into two major categories: conventional storage (tanks) and demand type water heaters. Demand heaters, or tankless, lose some heat as the water circulates around the house. Storage tanks lose some heat at the tank, as well as during circulation. Since they use different energy sources for the heat, it is not a simple, straightforward determination that a lower amount of heat loss is better. Most homes use gas or electric for heating water, and a tankless water heater to replace a storage tank using the same energy source is simple and will be more efficient. The improved efficiency is more noticeable in households that use less hot water. This is simply because the water is not cooling off during storage if it is not held in the tank for long.
Solar water heaters in this region will have a storage tank and use an indirect method of heating the water; in warmer climates this may not be case since the water can be directly heated by the sun and circulate through the system. Because Maryland has temperatures below freezing, a heat conducting liquid is pumped through the solar collectors and into a heat transfer coil that heats the water. Since your solar heat is free, the loss of a portion in storage may make sense. Solar collection requires dedicated panels for heating this liquid, so the installation will be more complicated and expensive than simply replacing a gas or electric water heater tank.
Geothermal heat pump water heaters can be installed alongside a geothermal HVAC system if you are building a new home or replacing your heating and air-conditioning with one of these. Because the installation of a geothermal system is expensive, it is not likely to be a cost-effective choice if it is just a decision about the water heater, but as a pair these make great sense. These systems take heat from the ground during the winter or from the air during the summer and use it to heat the water.
