Because of its popularity, tankless water heaters are now being used by most people due to its efficiency and energy-saving features. As the name implies, users will no longer have to deal with their traditional water heating process wherein they have to store hot water in their tanks. Old models use more energy as it reheats the water now and then while tankless water heaters will create hot water on demand.
The pursuit of making better and more efficient modern appliances that help us save money and energy has pushed the manufacturers to develop more advanced devices. Condensing water heaters are a newer innovation in tankless water heater technology that claims to offer multiple promising benefits that increase efficiency as well as the durability of the heater.
Tankless water heaters work very simply. The water that goes through the pipes is heated and then it’s ready for use. However, there are two most common types of tankless heaters that one may consider before buying.
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Condensing vs Non-Condensing Tankless Water Heaters | A Comparison
Condensing Tankless Water Heater:
The process of heating water through combustion and gas burner takes place as you turn on the switch and prepare to use your hot water supply. As exhaust gasses are created, it can also help the tankless water heater in heating the water inside the unit as it also produces extra heat. This is the reason why condensing water heaters are efficient compared to other types.
Condensing tankless water heater has a second heat exchanger that is responsible for reusing exhaust gas which heats the water. This means that before the water goes into the main heat exchanger, it is already exposed to these warm gasses that help cold water achieve their desired temperature. As it extracts heat from exhaust gasses, it will also produce vapor or steam which becomes condensation as it cools down.
As the exhaust gasses are not extremely hot compared to non-condensing type, around 100 F, the ventilation used for condensing tankless water heaters are not as expensive compared to the other type. However, due to condensation, this may also lead to corrosion. Because of this, it is also important to choose materials that may prevent this from taking place, stainless steel alloys are recommended.
Non-Condensing Tankless Water Heater:
Compared to condensing water heaters that vents exhaust gasses inside the unit, non-condensing will immediately vent the exhaust gasses outside. This type of tankless water heater which heats the water by the gas burner and since the gasses are vented right away. It loses about 20% of the heat that helps the water become hotter.
Non-condensing tankless water heaters also require more specific venting materials as the temperature may reach 300 F. The usual PVC type of vents that can be used with the condensing type may not be able to handle the heat that it produces.
With that said, it would cost more to install a venting unit for this particular type of tankless water heater.
Which is Better?
In all consideration, most would say that condensing tankless heater is more effective when it comes to heating your water supply. However, it should also be taken into consideration that there are times that this type would not condensate due to air temperature and it’s surrounding. Nevertheless, a non-condensing type is also effective; users would only have to be ready for some additional expenses that it may require when it comes to its venting units.
Relatively, non-condensing tankless water heaters are less expensive compared to the other type. On the other hand, condensing tankless water heaters may reduce the expenses for making it able to run overall. It is already established that condensing type of water heater is more efficient than the non-condensing type for about 10 to 15 percent. But other factors can be considered. Otherwise, there wouldn’t be two types available in the market.
Most non-condensing types are a bit smaller than the condensing type. It would also require an indoor combustion air but only requires minimal maintenance done by professionals. For condensing tankless water heaters, it does not need any indoor combustion air but will require annual maintenance done which could vary depending on the type of water in your area.
Things to Consider Before Buying Water Heater
In any home equipment that we are planning to buy, it is necessary to ensure that we will be able to conserve energy usage while still being able to maximize its functionality. Switching to a tankless water heater will unquestionably require you to make a bigger investment which could double or triple what you spent with your traditional water heater.
However, think about it, because it will save a lot on your monthly bills as well as be able to enjoy more hot showers for many years to come.
Aside from choosing the brand, size and some other features, it is always best to have a professional check your house and be able to anticipate other repairs or upgrades that you might need prior to installation. Not only it gives you more time to budget the amount needed but also give you peace of mind that your house is ready and that it is safe for everybody.

Hi, This is Luis. Author at “TheHeatersGuide”. I am a graduate in Mechanical Engineering. Currently researching on heating technology. However, I have learned many home heating techniques and still learning the home heating technolgy. And I love to share my research and reviews.