In water heater promotions, the term “eco friendly water heater” or “green water heater” usually refers to a water heater that produces low NOx and carbon dioxide pollutants, and efficiently uses non-renewable energy resources such as natural gas. Although a high efficiency tank water heater or a tankless water heater is better than a traditional tank-style unit, it is not truly an eco friendly or green water heater.
An eco friendly or green water heater is totally non-polluting and utilizes renewable and sustainable sources of energy. The sun is such a source of energy, and in a sunny climate you can save up to 90% on your water heating bills by purchasing a solar water heating system. Even if you live in the snowbelt, you can save 50% on your operating costs, while helping the environment at the same time.
Many solar water heating systems are now commercially available. For the eventuality of rainy or snowy days, most of these systems include a backup system of electric heating elements in the solar water tank. These elements are only activated when the water temperature in the tank falls below a preset threshold.
In some solar systems, the solar panels are only used to preheat water for an electric or gas-fired water heater. While, not actually being a green or eco friendly water heater, this hybrid system ensures sufficient hot water, while providing significant energy savings.
Solar powered water heaters are more expensive than gas or electric models. However, by taking advantage of the 30% Energy Star federal tax credit, as well as additional state rebates, you will be able to significantly reduce the cost of you solar powered water heater.
These green water heaters have a lifespan of well over 20 years, and with the 50% to 90% you will save on your operating costs, your solar water heater will pay for itself in less than 10 years. As a further incentive, by installing a solar hot water heating system, you will increase the value of your house.
There are many solar hot water heaters on the market. Rheem makes two solar water heating systems that have recently received excellent reviews The Rheem Solaraide System is a passive solar water heating system, and their Solpak System is an active solar system.
A heat pump water heater is another eco friendly water heater that derives its energy from a renewable energy source. A heat pump water heater is able to extract heat from the surrounding ambient air, and use this heat to heat water in a storage tank.
A heat pump water heater works just like an air conditioner or refrigerator in reverse. As a fan pulls air into the heat pump, the heat in the air is absorbed by an eco friendly refrigerant inside an evaporator coil. The hot refrigerant is then compressed. This raises its temperature and causes it to vaporize. The superheated vapour then circulates through a condenser coil which wraps around the inside of the hot water tank. As the vapour circulates through the coil it transfers its heat to the water in the tank.
The tank itself is actually an electric water heater, with two heating elements that serve as backups. Heat pumps heat water slowly, so during times of high hot water demand, the heating elements in the tank can heat the water in tandem with the heat pump system. Because they have two heating systems these water heaters are often called hybrid water heaters.
Although heat pumps can work in all climates, they are more efficient in spaces that have a year round temperature of over 40 degrees Fahrenheit. As the heat pump extracts heat from the air passing through it, the air is dehumidified and cooled. The cooled air can be vented to the outside during the winter, or can be integrated with a space cooling system in the summer.
These green water heaters cost more than traditional electric tank water heaters, but they are two or three times more efficient. Besides saving 50% to 70% on your energy bill, you can also claim a 30% Energy Star tax credit.
You can purchase a hybrid heat pump water heater from several manufacturers. Recommended models are Rheem’s HP-50 heat pump water heater, the GE hybrid water heater, Stiebel Eltron’s Accelera W300, and the Roboheat heat pump water heater.
You can also purchase a stand-alone, add-on heat pump, and retrofit it to work with your existing electric or gas water heater. AirGenerate’s Air Tap A7 is a small heat pump that is designed to sit on top of your storage tank water heater. It will more than double the efficiency of your water heater, making it into a more eco friendly, green water heater. The larger E-Tech R106K-5 (Applied Energy Recovery) has excellent reviews and will heat sufficient hot water for a family of five.