Gas condensing water heaters are similar to a traditional tank-style gas heater, but much more efficient. Traditional gas heaters vent combustion gases directly to the outside, but condensing versions are designed to capture those gases and recycle their “waste” heat back into the system.
A standard gas storage water heater is like a water tank sitting atop of a gas fireplace with the chimney running straight up through the middle, exiting at the top. A gas condensing water heater has its "chimney" or flue designed with greater surface area. The heat and combustion gases have much farther to travel before they exit the water tank, so more heat is transferred to the water in the tank.
This type of water heater cuts energy usage by 30% and can save more than $100 a year! This might seem like a small savings, but if just five percent of the gas water heaters sold each year in the US were Energy Star qualified gas condensing models, the reduction in greenhouse gas emissions would be equivalent to taking almost 17,000 cars off the road!
For those still concerned that a tank water heater might leave your visiting in-laws with a cold shower, fear not. Because gas condensing water heaters are so efficient, the tank heats up almost as quickly as it’s filled!
Heat Pump Water Heaters
You’ve probably heard of using heat pumps to heat and cool your home, but the same concept can also be used to heat water. Heat pumps work like a refrigerator in reverse – instead of removing heat from an enclosed box, a HPWH takes the heat from surrounding air and transfers it to water in an enclosed tank. Because the technology uses electricity to move heat instead of generate it, you’re left with a much more efficient system.
A good option for homeowners that rely on electricity to heat their water, heat pump water heaters can save $300 a year on electric bills! The units do cost more up front, but the payback period is only about 3 years, meaning you start saving money after that. For a small increase in upfront costs, the broad environmental impact is staggering. According to EnergyStar.gov:
If everyone buying an electric water heater this year chose an ENERGY STAR qualified heat pump model instead of a standard model, we would avoid 19.6 billion pounds of carbon dioxide emissions. That's the equivalent of taking 1.6 million cars off the road.
For more information or help choosing the right product for your home, visit Energy Star’s website.