Woodnet Forums
HVAC & H2O Heater - Printable Version

+- Woodnet Forums (https://www.forums.woodnet.net)
+-- Thread: HVAC & H2O Heater (/showthread.php?tid=7231204)



HVAC & H2O Heater - Halfathumb - 02-28-2016

Before I wear out my welcome here. My previous 2 posts are in reference to an electric heater that's connected to a Geothermo unit. Is it possible to connect a tankless water heater to the HVAC? Or would be economical to remove the old water heater, bypass the HVAC and just use an elec. tankless unit?


Re: HVAC & H2O Heater - Robert Adams - 02-28-2016

That would be called a desuperheater. Not sure what you are trying to do though.


Re: HVAC & H2O Heater - fredhargis - 02-28-2016

The way mine works is there is a storage tank (just a passive water heater) for the geo to pre heat the water which then feeds the active water heater. Don't see why that same thing couldn't be done with a tankless, but I'm not sure what the gain, if any, would be.


Re: HVAC & H2O Heater - Halfathumb - 02-28-2016

Robert Adams said:


That would be called a desuperheater. Not sure what you are trying to do though.




I thought maybe I could eliminate the 40 Gal water heater and use a tankless system. My research keeps coming up empty though.


Re: HVAC & H2O Heater - Halfathumb - 02-28-2016

fredhargis said:


The way mine works is there is a storage tank (just a passive water heater) for the geo to pre heat the water which then feeds the active water heater. Don't see why that same thing couldn't be done with a tankless, but I'm
not sure what the gain, if any, would be.




I'm coming to that conclusion too. How long have you had your geo unit? Mine is 2 years old but this unit replaced the original geo from when the house was built in 1998. I'm surprised the water tank has held this long with no other problems.


Re: HVAC & H2O Heater - blackhat - 02-28-2016

Your current system is about as cheap to operate as it gets short of solar. I would not consider electric tankless.


Re: HVAC & H2O Heater - fredhargis - 02-29-2016

Mine was installed in 2010. We will moving in a few months and the place we bought has geo that was installed in 1998, but without the desuperheater (or at least with the hot water part). My plans are to replace that system with pretty much what we have here since I like it so well.


Re: HVAC & H2O Heater - Halfathumb - 02-29-2016

Thanks Fred & Blackhat.

Jim


Re: HVAC & H2O Heater - Robert Adams - 02-29-2016

There are heat exchangers you can add to any split system. They go in line of the high side line and are basically a heat exchanger. I would assume they have systems for geothermal that don't already have a desuperheater.

Geothermal isn't popular here because the ground temp is too high and drilling wells is cost prohibitive often starting around $20 ft and a basic water will is now 500' and deeper to get good water.
I was going to do get here but it'll never pay off unfortunately.


Re: HVAC & H2O Heater - fredhargis - 02-29-2016

To be honest, it would be a very long payoff here (thought it would pay eventually). The kicker at the moment is the 30% fed tax credit (expires this year). With it, the geo only cost about $1500 (+/-) more than the air source heat pump/has furnace I was going to buy. But I also think the price is coming down on them somewhat, but I'd bet it's still a long payout.