You’re thinking about buying a tankless water heater but you don’t quite know the difference between the two main designs:

  • Condensing tankless water heater
  • Non-condensing tankless water heater

You get the tankless part. They don’t store water in a tank for you to dip into when you need it. They heat the water when you need it, so you only pay for the amount of heated water you use and not the repeating cycles that keep the water hot all day.

You already know you want a condensing unit. Here’s why you should stop renting and opt for ownership.

hot water tankYour tankless water heater creates steam or water vapour as a byproduct, which cools or condenses on a surface.

The condensation is acidic and will corrode all kinds of materials.

A non-condensing tankless water heater vents the scalding byproducts, which cool down outside the unit. This stuff is hot, with temperatures around 150 degrees C, and must be vented through heat resistant, corrosion resistant channels. That means:

  • The materials to build the non-condensing unit are expensive.

When heat is vented, energy is wasted. You spend money to burn the fuel and you should get as much of that energy as possible in the form of heat.

Non-condensing units are about 80{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} efficient, meaning around 20{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2} of the heat is wasted through venting.

Can you guess why condensing tankless water heaters are so popular?

Condensing tankless water heaters recycle the extra heat, venting the vapour only when it’s no longer useful for the heating process, somewhere around 38 degrees C.

Since the vapour from a condensing tankless water heater vent is much cooler, it doesn’t require the same expensive materials. A standard PVC pipe is all a condensing unit needs.

tankless water heaterSince the condensing unit reuses the exhaust heat, they achieve efficiency in the area of 98{6369897c66410f53ef897a90d73c2d12c99a8251621b6aa0889d3e95dfbde6d2}.

The exhaust gases are cooled and the condensation water is collected inside the unit. The heat exchanger takes care of this, and has to be of higher quality and non-corrosive material inside the condensing tankless water heater. It is made using a similar material to the venting channels in a non-condensing unit.

The collected condensation water also has to be neutralized before draining. This is done through a built in filtration system.

What does this all mean?

The two types of tankless water heater are built differently but use similar materials, so you don’t necessarily save money at the point of purchase by choosing one model over the other. However, a condensing tankless water heater achieves greater fuel efficiency, a significant source of long term savings.

Efficiency is the primary factor most buyers look for in a new tankless water heater, and a condensing unit is the most efficient available.

Get in touch with a member of our team today and find the most efficient upgrade for your hot water system today.


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