Condensing vs Non-Condensing Tankless Water Heaters?

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Condensing vs Non-Condensing Tankless Water Heaters
Condensing vs Non-Condensing Tankless Water Heaters

Differences Between Condensing & Non-Condensing
Tankless Water Heaters

Externally Mounted Navien Tankless
Externally Mounted Navien Tankless

As Tankless hot water heater end up being more popular there are an increasing number of options.

As the term applies tankless water heaters don’t have a water tank like the traditional water heaters. The water in a tankless system is warmed as it flows through its heat exchanger which is heated through combustion, more intense that your routine hot water heater.

In a typical combustion we burn the hydrogen content of the fuel as the hot gases are produced. One of these hot gases is steam or much better water vapor. Now when these steam gases are cooled they become water that we normally describe as condensation. The condensation water is acidic (pH 3-5) and thus corrosive. It will corrode most metals and other products.

A Non-Condensing tankless hot water heater will push these hot gases through its vent to the outside (or out into the air if it’s externally mounted to the home) They will then cool off outside the system. These gases have temperatures around 300 degrees F and need to be vented through non-corrosive venting materials that can hold up against the heat. Here is unique stainless-steel category 3 venting used, which is pricey.

In the combustion procedure fuel was burned and that energy was utilized to heat the water, although not all of it. Since the hot exhausting gases include heating energy that is not utilized to heat up the water and are wasted by venting them to the open air. The hotter the exhaust gases are the less energy is used in heating the water and for this reason lower efficiency. Non-condensing units have performances around 80%, implying around 20% of the heat is squandered and exhausted.

Condensing Tankless Hot Water Heater

Condensing water heaters draw out the additional heat from the exhaust gases through numerous methods and for that reason exhaust cooler gases, normally around 100 degree F. As discussed prior to cooling the exhaust gases produces condensation, in this case inside the system. Because the exhaust gases are now much cooler a less costly venting product can be used, mostly standard PVC schedule 40 is used as it can quickly stand up to the heat and the corrosively of the gases. Because we have used the residual exhaust heat to heat the water we have achieved higher performance in the high 90% range (as much as 98%). As a note, a condensing unit does not constantly condensate, surrounding air temperature level and air humidity are important factors. The manufacture declared effectiveness are attained mostly in laboratories under controlled conditions and reality values maybe lower.

Considering that the exhaust gases have actually been cooled inside the unit the condensation water is gathered now inside the unit. The heat exchanger is the heart of the tankless water heater. It has now to be of higher quality and non-corrosive material to hold up against the corrosiveness, normally made from unique stainless steel alloy. The collected condensation water has to be reduced the effects of prior to it can be drained to the outside. This can be done through special filtering or dilution.

To Summarize 
Condensing Tankless Water Heaters are extremely effective (approximately 98%), genuine energy savers and utilize inexpensive venting material. They are slightly more expensive to manufacture but are over all on par with non-condensing tankless water heaters that require to utilize costly stainless-steel venting materials and are less efficient (about 80%).

South End Plumbing specializes in tankless water heaters, so remember, we are just a click away. We also specialize in leak detection Рgive us a call! South End Plumbing is one of the only companies that will give you a free estimate. Call us at 704-919-1722 or fill out the form online to schedule a visit.

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