# How Well Would A Nyle/Geyser Work With A 40 Gallon Water Heater?



## velvetfoot (Apr 25, 2014)

A 40 gallon electric water heater works for us.  How well would an external heat pump water heater work with it?  Thanks.


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## woodgeek (Apr 25, 2014)

suspect it would work fine.  Lower EF than an all in one, otherwise ok.


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## DBoon (Apr 26, 2014)

By "how well would it work?", if you mean "will we run out of hot water?", that will depend on how closely spaced peak hot water loads are.  

In summertime with warmer basement temperatures and warmer water inlet temperatures, my 50 gallon tank recovers in about 4 hours with my Geyser, but in late fall or early spring (I shut it down in the deep winter) when basement temperatures are nearer to 50 degrees F and water inlet temperature is much colder, the recovery time can be nearly twice that.  

So if you don't have water conserving appliances and showerheads, I would say you will have a problem unless you carefully space your loads. 

If you have water conserving appliances, but do everything at one time (dishwasher at 5 gallons, two loads of laundry at 5-8 gallons of hot water each, a few showers in a row at 5-10 gallons of hot water each), things might get pretty tight as the unit recovers.  You would likely be ok in the summer, but not in colder times.  If your family is forgiving, no problem.  If the last shower in the sequence is cut short for an unforgiving family member with the memory of an elephant and low forgiveness, expect to hear about "that stupid new water heater thing that you put in that never seems to give us enough hot water"   Know who your customers are and what they want!  Note: this is an example and did NOT happen to me, but it would if I didn't plan well.  

Keep in mind too that you really have about a 120-125 degree F temperature limit on the HPWH for maximal efficiency.  I made the mistake of trying to use mine to heat the tank to 140 degree F so that I would have more "capacity" to handle lower temperature hot water demand, but the HPWH efficiency really starts to go downhill a lot after 130 degrees F and is negatively affected beyond 120-125 degrees F.  I learned this through my own Kill-a-Watt measurements, and I think  Tom in Maine confirmed this in a different post as well.


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## Slow1 (Apr 26, 2014)

Interesting post - I have a 50 gallon tank and have been planning on installing a Geyser.  For the last week I've been calling their number and getting voicemail 2x a day.  I haven't been able to get through to anyone even choosing "Operator".  I'm beginning to wonder what would happen if I ever did get one and need support!

My emails have gone un-answered, as has my submission through their "Contact us" page.  

Does anyone know of another add-on HPWH options out there?


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## maple1 (Apr 27, 2014)

Slow1 said:


> Interesting post - I have a 50 gallon tank and have been planning on installing a Geyser.  For the last week I've been calling their number and getting voicemail 2x a day.  I haven't been able to get through to anyone even choosing "Operator".  I'm beginning to wonder what would happen if I ever did get one and need support!
> 
> My emails have gone un-answered, as has my submission through their "Contact us" page.
> 
> Does anyone know of another add-on HPWH options out there?


 
Yes - the Nyletherm. Predecessor to Geyser I believe. Do a search on that and you should find lots to read about. If you haven't read it yet. You can drive to Searsport ME and get one for $300.


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## DBoon (Apr 27, 2014)

Interesting lack of replies, Slow1, from Geyser.  I have always had good luck getting a response from them, though I haven't had reason to contact them for >1 year.


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## Slow1 (Apr 27, 2014)

Maybe I'm just that unlucky on timing 

BTW, I was looking on their site trying to find detailed specs - does anyone know how much the water is heated in the uniti itself?  I.e. if 60* water is flowing into the geyser, what is the expected temperature of the water flowing out?  Is it heated all the way to 120* or does it take multiple passes through the unit to get up to full temp?


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## velvetfoot (Apr 27, 2014)

So, could you operate in a hybrid mode like the Geospring?  I'm not even sure how that works, whether there is some computer logic behind it, or what?


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## Slow1 (Apr 27, 2014)

My understanding is that yes, you could have it configured for hybrid like mode.  Set the temp for the Geyser to say 125, and your 'other' heating to 115 - this way the 'other' will kick in when the temp falls, but the Geyser will take care of standby losses as well as any small useage.


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## woodgeek (Apr 27, 2014)

Slow1 said:


> My understanding is that yes, you could have it configured for hybrid like mode.  Set the temp for the Geyser to say 125, and your 'other' heating to 115 - this way the 'other' will kick in when the temp falls, but the Geyser will take care of standby losses as well as any small useage.



I would add that this would be the upper coil, so you only get a bubble of hot water fast, rather than heating the whole tank.  I'd leave the lower coil off.  Then you'd get mostly HP BTUs, but a burst of conventional when you want it.


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## Where2 (Apr 28, 2014)

Slow1 said:


> Does anyone know how much the water is heated in the uniti itself?  I.e. if 60* water is flowing into the geyser, what is the expected temperature of the water flowing out?  Is it heated all the way to 120* or does it take multiple passes through the unit to get up to full temp?



I would NOT expect the water was heated to full temp on one pass. It's not intended to operate like a tankless system. How much heat is added to the water on each pass through the heat pump should be relative to how much heat energy can be extracted from the surroundings. It is my understanding that the performance varies depending on the temperature of the room where the device is running.


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## woodgeek (Apr 28, 2014)

Good point.....since the COP falls with the temp of the water being heated, it would make more sense to do multiple pass. ??


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## DBoon (Apr 28, 2014)

I've measured the temperature of an uninsulated hose on my Geyser using an IR thermometer, and my recollection is that it is about a 3-4 degree F temperature rise when starting from a cold tank.  

My Geyser disables the lower element, and I turn the HW heater element breaker off in the spring, summer and fall.  In the winter, I turn it on and use that to heat the water and turn the Geyser off.  I have this element set to 140 degrees F and it makes enough to keep my wife and I in hot water provided that we don't do too many things that need hot water one right after another.


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## velvetfoot (May 2, 2014)

maple1 said:


> You can drive to Searsport ME and get one for $300.


Hey, I'm retired now!  Road trip!  First will do some more reading.


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## maple1 (May 2, 2014)

velvetfoot said:


> Hey, I'm retired now!  Road trip!  First will do some more reading.


 

If we could all get our ducks in a row & poop in order - we could all do a road trip & have a Hearth party at Toms.


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## velvetfoot (May 2, 2014)

Well, I just ordered one off eBay for 365.  It's pretty far.


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## velvetfoot (May 14, 2014)

Installed, and seems to be working!  See other thread if interested:  https://www.hearth.com/talk/threads/my-nyletherm-thread.127866


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