Hybrid Water Heaters Pros and Cons
A conscientious family, taking short showers, washing clothes in full loads only, and doing all the other daily household chores while using water wisely will still consume 550 gallons of hot water a week. A few extra minutes in the shower for a family of four every day will easily increase that to 700 gallons of hot water a week. To put this in perspective, 700 gallons is a 3-year supply of drinking water for one person. We must learn to conserve or risk running out of water in the future. It doesn’t hurt that conserving hot water also saves you money.
In the world of residential water heaters, there are basically four categories:
The Standard Water Heater is what many of us have installed in our homes. In previous posts, we looked at the technology and costs of installing and maintaining these hot water systems. Tankless water heaters eliminate the storage tank sitting in the corner of your garage and thus any standby heat loss associated with maintaining your hot water 24/7; but they also have a higher initial purchase price, much higher initial installation cost and continuing maintenance issues for the life of the unit. Tankless Hot Water has its place but in general, is not the best choice as a direct replacement of an existing conventional storage tank system.
There is no doubt that a Solar Water Heater can save you thousands of dollars over its lifetime. It can also increase the resale value of your home. But it also has the highest upfront costs and the most long-term maintenance requirements. A Hybrid model can supply a family with hot water: Hybrids are a Heat Pump Water Heater with Standard Electric Heating Element Backup.
Instead of generating hot water by burning hydrocarbons, or brute force using electrical resistance heating, a heat pump uses the same technology that is in your refrigerator to pull heat from the surrounding air and put it into your hot water. The Heat Pump gets the additional name of Hybrid because the storage tank is equipped with electric heating elements found in Standard Electric Water Heaters which can kick in during times of high demand.
As an example, one system made by General Electric is called the GeoSpring. It is designed to drop right into the same physical space as a Standard Electric Water Heater.
The GeoSpring water heater combines energy-saving heat-pump technology with traditional electric elements using a fraction of the energy. The integrated compressor and evaporator use a fan to draw in ambient heat from surrounding air to warm the cool liquid refrigerant causing a phase change from liquid to gas which is then compressed, raising the now gaseous refrigerant temperature even higher. This hot gaseous refrigerant then runs through heat transfer coils that wrap the high efficiency storage tank all the way to the bottom, delivering its heat into the water inside. This results in another phase change in the refrigerant from hot gas to warm liquid. The warm liquid refrigerant then passes through an expansion valve which cools it even further and the process repeats.
This innovative technology creates the same amount of hot water as a traditional electric water heater while reducing heating expenses up to 62%. Plus, the GeoSpring comes loaded with tech features like an energy-efficient Heat Pump mode, Hybrid mode, and Vacation settings.
The GeoSpring is made in America. Currently some 60 million homes in the U.S. use standard electric hot water heaters. By absorbing heat from the ambient air and transferring it to the heated water, the GeoSpring uses dramatically less energy. As standard heaters are replaced with the new heat pumps, the demand for electricity will also go down.
Costs of both Tankless and Solar Water Heaters can vary greatly due to installation variations, equipment availability and other factors.
There will be more information about Heat Pump Water Heaters over the next few years. New federal regulations are due to become effective on April 16, 2015 that will require electric water heaters larger than 55 gallons to have Energy Factors (EF) greater than 2. The exact EF for a given water heater is based on a formula that factors in the usage, the storage volume, and input energy, but generally speaking, the higher the number, the better. But the required minimum EF 2 can only be achieved with heat pump technology.