desuperheater fitting for water heater tanks

[Chad711]

Where is the heck can I find these, they screw right in where the drain for the water heater is, has a chunk of 1/2 copper that goes inside the 3/4, then has an inlet/outlet and drain. Some of you may know what Im talking about. For Geo systems...

Local parts guys have no idea what Im talking about. Also, these things plug up pretty quick dont they...

[hvacguy55]

They plug up REAL quick. Every time. Stopped using them.

[Chad711]

Thats what I was thinking, the water has very little clearance. I "made" one since I wasnt able to find one, it works!

[protechplumbing]

You are referring to what's known as a "coaxial fitting". As hvacguy said, if you have very hard water in your area they will get clogged up easily.

[mo geo man]

Have to agree the coaxial method just leeds to maintenance problems if the water has any impurities. We quit piping that way a few years ago. Our manufacturer still shows piping it coaxial in there literature.

[protechplumbing]

The best thing to do is buy a larger solar tank. Look for tanks designed for open loop solar applications. They will have 5 ports on the top and 3 dip tubes. You usually get more mileage out of a bigger tank when hooked up to a desuperheater because you can store the heat longer and not depend on the electric resistance elements in the heater so much. Disconnect the lower element to so that it's not firing when the desuperheater is working.

[mseng]

Talk to the parts supply house about a water cooled condenser. It will hold up well with lime build up for a few years.

[protechplumbing]

The main issue with them liming up is that when they draw water through a coaxial fitting at the bottom of the tank they picku sediment in the bottom of the tank. This sediment then clogs the desuperheaters smaller water passages. This is not an issue when hooked up to a tank with 2 extra dip tubes that are cut 6" from the tank bottom.

Its pretty sillly to hook them up to a standard water heater from both an efficiency and reliability point of view.

[norm36]

we use the t&P port on the top with a 3/4 brass nipple to a brass tee, then pull the drain out ant use a 3/4 brass nipple and tee there too it has never given us problems

[MWenzel]

We no longer use coaxial fittings as well. I'm not sure what water heater you are using or if this will help but here's a photo of the desuperheater piping using a Vaughn.



Ill also try to drum up some different diagrams that could assist you in a different method of piping without need of a coaxial.

[SkyHeating]

We always use a 50 gallon desuperheater storage tank before going into the water tank and have had no issues with this so far and from what I can tell is the most efficient. Plus we dont' need to use that silly 4 way fitting that plugs up, we just push the water back in through the drain at the bottom and pull out of the cold water inlet in the top.

Then again, in Oregon we are required by law to hire a plumber and pull a permit for anything beyond two nipples and two 18" water flex lines so my plumber brings the fittings he needs.

[MWenzel]

Then again, in Oregon we are required by law to hire a plumber and pull a permit for anything beyond two nipples and two 18" water flex lines so my plumber brings the fittings he needs.

Same issue with plumbing in Mass, then head over the border to here in NH and were allowed to do the piping ourselves.

[hawkeyehvac]

We pull off of the cold water inlet, pipe it to the desuperheater, and then pipe it back to the bottom of the waterheater using a 3/4inch brass T with a boiler drain on the opposite side.

[parabrush]

Hello

I live in Ontario Canada. (hopefully that's a good start to my thread HA HA)

I researched on this forum about HWG (hot water generators) and the proper plumbing into a single electric hot water tank.

I purchased a 10 year old home with a 2005 model Climate Master GSV 060 (5 ton) geothermal unit with HWG. I have owned the home for 2 months and noticed a SUBSTANTIAL amount of electricity consumption. Last month (30 days) 3528 Kw/h. Yep, in Ontario Canada $0.21 per Kw (tax included) equates to $740.00 for the 30 day period. Yeah WOW.

So, we have no gas what so ever in our area. Geothermal Closed Loop system. Yesterday I conducted an experiment to shut down my hot water tank for 6 hours. It is a 80 Gallon REHEEM unit. I have no bunker (secondary tank). My energy consumption dropped in 1/2 for this period compared to the last 60 days. Here is my concern, I think my HWG is plumbed incorrectly to the HWT. I wanted to enter a picture but cannot figure out how so I will try to explain it. Two lines run from the HWG. (in / out). These two orange lines run into a four way T on the bottom of the tank. One is a drain, the other goes into the tank. Does this not create a vacuum drawing the pre-heated hot water from the tank back into the HWG of the geothermal unit?

Another little note: on the hot output (on top of the tank) is a circulation pump which circulates the hot water throughout the large home to acquire on demand hot water at the faucets. It's 1/25 HP less than 25W.

Any specialists that can help me on this would be VERY appreciated. I was told I cannot just close the valves on the bottom of the tank because the HWG pump needs constant circulation. Although, could I just disable the HWG pump and then turn off the valves if in fact this is why all my energy is being drawn from the Hot Water Tank?

Please help!

[epmiller]

Hello <snip>

I researched on this forum about HWG (hot water generators) and the proper plumbing into a single electric hot water tank.

I purchased a 10 year old home with a 2005 model Climate Master GSV 060 (5 ton) geothermal unit with HWG. <snip>

<snip> Two lines run from the HWG. (in / out). These two orange lines run into a four way T on the bottom of the tank. One is a drain, the other goes into the tank. Does this not create a vacuum drawing the pre-heated hot water from the tank back into the HWG of the geothermal unit?

Another little note: on the hot output (on top of the tank) is a circulation pump which circulates the hot water throughout the large home to acquire on demand hot water at the faucets. It's 1/25 HP less than 25W.

Any specialists that can help me on this would be VERY appreciated. I was told I cannot just close the valves on the bottom of the tank because the HWG pump needs constant circulation. Although, could I just disable the HWG pump and then turn off the valves if in fact this is why all my energy is being drawn from the Hot Water Tank?

Please help!

First off, if the HWG in/out lines go to two of the 4 ports on a 4-way cross at the bottom of the tank it would just be a short circuit and very little would be done to help your domestic hot water. Doesn't go through the tank at all. If that domestic circulation pump is plumbed in down at that 4-way I would need to see a diagram and I could be barking up the wrong tree. I also don't like a HWG without a "bunker" tank. The electric elements are going to hold the temperature and you gain very little to nothing unless you have a HW demand while the geo is running. And that requires them to be plumbed in correctly!

The inlet to your HWG should be plumbed to a Tee at the cold inlet to your domestic HW tank. ClimateMaster wants the outlet to go into a Tee installed at the tank drain fitting. Since we have always installed our geothermal systems with a non-electrified water heater (bunker) ahead of the electric water heater, instead of the Tee at the drain fitting (hate the tripper it makes) I remove the lower element and return the output of the HWG into that opening. Drain runs cold even with the geo system operating but it looks a bit odd to the uninitiated with a hole cut into the bottom element cover and a pipe going in.

To me, HWGs don't make much sense when the system is running for heating. They make the most sense in AC. You better have a really hefty ground loop with a lot of capacity designed for both space and domestic water heating. Around here the HWG isn't often taken into account when designing the ground loop.

Hope that helps.

EPM

[GT1980]

these aforementioned 4-way T's for recirc in HW tank drain ports, - in one port have fowled in nearly every one of seen installed since the 1980's.

The PEX tube installers' flood-baths in folks homes are less pretty than where plugged at the 4-way.

[GT1980]

PEX has not held up to the convected HW able to hit 170f RARELY when a circ pump is off and a GHP desuperheater is below a cold fluid in a tank, forcing slow , sometimes over-heated pressurized hot water to pop-off the PEX at the inlet to the GHP ( reversed heat migration, likely during restricted air flow/ blower-failing to wipe off heat/ etc).

[Tom Thermo]

@ Hawkeyehvac Just curious based on my solar hot water experience why you wouldn't draw cold water from the bottom of the water heater, heat it in the desuperheater and then return it to the top of the tank where the warm water is? Stratification is your friend.