Anybody care to share information about using the new style tankless water heaters for floor heat? I need to replace my old Jarco 350K btu money pit with something new and more energy efficient.
I’ve been doing some extensive research and comparing different demand heaters, Takagi, Paloma, Rinnai to name a few. Some are condensing units and some non-condensing. The non-condensing are usually about 84-85% efficient and the condensing units are 94-98% efficient. The condensing units can be vented using PVC while the less efficient units need to be vented using stainless steel vent pipe with a condensation drain added to the vent stack which is more costly.
Some of the heat exchangers are copper and some are Stainless steel and copper. The condensing units usually use stainless and copper.
The problem I’m having is trying to determine what will work and how well it will hold up running Polyethylene Glycol in the system. Most of these demand heaters are manufactured for heating “Water” and don’t offer details or suggestions when using them in hydronics or snow melt systems which is basically what we have.
I have my eye on this model after doing some research…It’s the Paloma PHH-32RDV. It’s a condensing boiler with a 94% efficiency rating. It has a copper/Stainless steel heat exchanger, 199,999 btu rating, can be vented using PVC, has a direct vent cold air intake, and can heat water +35° at 9.5 GPM and 77° at 4.9 GPM Temperature rise.
What are the pro’s and con’s of using a heater/boiler like this? This one is realitively inexpensive compared to “Boilers” on the market. The one I mention can be bought for less than $1300 which is considerably cheaper than the Takagi TM32 commercial that only uses a copper heat exchanger and has to be vented using Stainless Steel Pipe. I know some of you are using these demand heaters for floor heat. So tell us what model your using, why, and how well its working for you. Thanks!