Venting Your Tankless Water Heater
Tankless, or "On Demand" water heaters are becoming more and more popular with homeowners. It is estimated that within 5 years, more than 50% of homes in the United States will have them installed.
Just like gas storage tank water heaters, require venting. However, tankless hot water heaters require special venting that blows the hot exhaust outside. Unlike traditional gas water tank heaters, gas tankless water heaters offer the homeowner a lot more versatility in venting options.
Several advances in unit design have made the installation of energy-efficient tankless water heaters less expensive and much more space saving than their storage tank counterparts.
Tips for Venting a Tankless Water Heater
Tankless water heaters need to bring in and vent exhaust so there are two different ways you can vent your water heater, direct venting and power venting. Direct-vent units consist of two vents which are placed outside the home. One of the vents brings fresh air into the unit and the other vents the exhaust. Direct-vent units allow the water heater to fit in smaller spaces.
Power-vent units only require an exhaust vent because they need to be placed in a larger area so they can bring in adequate air to aid in the combustion. Even though you need more space for a unit that is power-vented, there is still a large reduction of space compared to traditional water heater tanks.
Mounting your tankless water heater outside frees up space indoors. Self-warming components allow units to withstand below-freezing temperatures outside and they don't require any additional venting.
Tankless water heaters make several different venting options possible. They can be vented through the roof or a side wall, creating more flexibility. Traditional gas water heater tanks need to be vented through the roof. If you prefer venting your tankless heater through you can because they use fans to blow exhaust from the unit.
Condensing tankless water heaters lower your installation costs. Units with condensing technology are up to 95% more efficient than units without condensing technology. Since condensing units emit a cooler exhaust, a PVC or polypropylene vent can be used, lowering the cost of installation.
Tankless water heaters with a concentric vent design offer additional safety benefits. A 5" concentric vent contains both intake and exhaust pipes, so the vent is cool to the touch. Also, if the exhaust pipe develops a leak the, it still stays inside the pipe, rather than leaking into the house.
Using a recess box will allow you to place a tankless unit inside the walls of the home. Doing this lets you maximize more space inside your home, rather than devoting it to your hot water heater.
You can also add pipe covers for a more appealing venting solution while conveniently concealing the pipes.