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Hybrid Water Heater

jasonhc73

Cat herder, and dog toy tosser.
Joined
Oct 1, 2019
Messages
1,921
Location
Wichita, Kansas
I just discovered what a Hybrid Water Heater is.
If you have solar, then that is by far the best way to go to save money in the long run.

I can't believe just how much less energy it uses as it is grid-connected. It is a heat pump. A refrigerator, in reverse.

I had no idea they even existed! It's my next project.
I know what I have now is at least 7 years old. :)
If I can make an 80 Rheem fit where my gas one is now, it's going in!


 
I like an air source heat pump outside. They can heat cool dehumidify and heat water with heat from air conditioning activity which boosts the efficiency of the ac side tremendously.

The thing needs to extract energy from the space you may be trying to control the temperature of.....

Like thermoelectrics hooked to the woodstove which sits next to the refrigerator the thing powers..... ding ding. Fight!

They are available i think .5 ton and up. Chiltrix hotspot energy has these along with appliances that connect your existing ac unit or refrigerator to the domestic water heating system.

The benifit of tossing wase heat that cost energy to remove into dhw use should be obvious. At least in the cooling season when its also hot at the outdoor exchanger.

Cold basement heating season, these water heaters lose efficiency same as (when the) ac (is) on full and trying to extract latent heat from the electrically cooled air.

Best place for heat pump water heaters might be on the porch or unheated garage.
Conversion losses.

Big refrigeration and climate control uses this (heat exchangers to dhw on ac units) to great success at facillities for some time now.
 
I just discovered what a Hybrid Water Heater is.
If you have solar, then that is by far the best way to go to save money in the long run.

I can't believe just how much less energy it uses as it is grid-connected. It is a heat pump. A refrigerator, in reverse.

I had no idea they even existed! It's my next project.
I know what I have now is at least 7 years old. :)
If I can make an 80 Rheem fit where my gas one is now, it's going in!



Hey, Did you try it out? Looks quite interesting
 
I have been using HPWHs for 6 years and they are great. The old GeoSpring had its problems but mine is still cranking along. The new Rheems are very good.
 
Hi.
I have been using a heat pump water heater for years. They are great. I have had an instance where I had one die on me as well. The failed one was a Rheem brand and they are warranted for 12 years typically. 7 years in, the compressor was having problems. The good thing here is that these have two options for heating water. Either heat pump or heating element or any combination of both. The compressor was going out, so I switched it to heating element only and had as much hot water as I needed until I could get the issue resolved. It is nice to have a backup system.

In this situation, there were no contractors near me that would even look at my unit to repair it. I called Rheem tech support and explained this and the tech helped me over the phone and could tell from my errors and the noise my compressor was making that the compressor was failing. These are totally sealed and non servicable units, so there is nothing to do here but send me a new one. By new one, I mean whole new hybrid water heater with fresh warranty.
They didn't sell the unit I had any more, so I got a newer and even more efficient unit for no cost to me. I did install the new unit myself and had to make a few pipe modifications where the new one didn't line up with the old one, but no big deal. So it was an ok process and I would purchase another hybrid unit in the future without hesitation, but be aware that no plumber nor A/C guy really wants to deal with these devices for warranty work. -At least near me.

Now, in your situation, I have a suggestion.... If you were to get a hybrid unit while your existing water heater is still functioning, you could still use the water tank of your old unit for heating water with the sun. -Assuming your home layout is convenient for this and it wouldn't be too much of a plumbing job to do it, also assuming you are living near some hot weather.
What I did was to take an old water heater and pipe my water supply (with ball valves for bypassing this in winter) to the old water heater that has been stripped of its sheet metal outer layer as well as foam insulation layer and down to just the steel tank that I painted black. Place this tank on its side in a good south facing location and let it be your hot water pre-heater.
This will only work in hot and sunny months, but will supply your hybrid water heater with preheated water from the sun at no cost to you other than the time and plumbing costs.
In summer, I typically heat water consuming about 24kwh of power per month according to my rheem unit's app. This is thanks to my preheater tank. With this setup, heating water costs me approximately $2.88 in electricity for the month for a family of three in the summer. I am also not fully optimized either since my water tank outside is standing upright and not on its side, so not optimally capturing the sun's heat. A tank on its side in my situation could supply me with nearly 100% of the hot water I need in the summer.
 
I just discovered what a Hybrid Water Heater is.
If you have solar, then that is by far the best way to go to save money in the long run.

I can't believe just how much less energy it uses as it is grid-connected. It is a heat pump. A refrigerator, in reverse.

I had no idea they even existed! It's my next project.
I know what I have now is at least 7 years old. :)
If I can make an 80 Rheem fit where my gas one is now, it's going in!


My friend and I installed a GE Geospring 50 gallon heat pump water heater in my off grid cabin about six years ago.

It has worked very well and I’m pleased with it.

We power it with approximately 3725 W of solar panels and 20 kWh of AGM storage batteries and an old Trace SW4024 inverter connected to a Trace 220 volt transformer, to increase the voltage.

We installed this heat pump in the crawlspace of my cabin and it actually helps keep the crawlspace cool and dry, which is very helpful in the Ouachita Mountains of western Arkansas.

There's a condensation hose line on the unit that carries the water created from moisture on the coils as the heat pump refrigerant lines do their work and extract moisture from the air.

This line drains out of the crawl space and really puts out a lot of water. As a result, the crawl space is quite dry and useful for storage.

I’ve heard that the were problems with the Chinese manufactured version of this particular brand of heat pump water heater.

Mine was apparently made in Kentucky, after GE brought their manufacturing for this unit back to the USA.

I really haven’t had any problems with it and it’s a pretty tough unit.

I’ve run it in heat pump mode only, ever since I installed it because my solar array isn’t large enough to power the resistance heating elements and the while point of installing it was to see if it would heat water for the cabin shower and kitchen.

In heat pump mode, it uses approximately 550 watts at 220 volts or about 2.5 amps (Amps x volts = watts).

I purchased this on sale at Lowe’s and also got a veteran’s discount, so my net price for the unit was around $800 - as far as I can recall.

It was a fun project to see if my array and balance of system could power it.
 
My friend and I installed a GE Geospring 50 gallon heat pump water heater in my off grid cabin about six years ago.

It has worked very well and I’m pleased with it.

We power it with approximately 3725 W of solar panels and 20 kWh of AGM storage batteries and an old Trace SW4024 inverter connected to a Trace 220 volt transformer, to increase the voltage.

We installed this heat pump in the crawlspace of my cabin and it actually helps keep the crawlspace cool and dry, which is very helpful in the Ouachita Mountains of western Arkansas.

There's a condensation hose line on the unit that carries the water created from moisture on the coils as the heat pump refrigerant lines do their work and extract moisture from the air.

This line drains out of the crawl space and really puts out a lot of water. As a result, the crawl space is quite dry and useful for storage.

I’ve heard that the were problems with the Chinese manufactured version of this particular brand of heat pump water heater.

Mine was apparently made in Kentucky, after GE brought their manufacturing for this unit back to the USA.

I really haven’t had any problems with it and it’s a pretty tough unit.

I’ve run it in heat pump mode only, ever since I installed it because my solar array isn’t large enough to power the resistance heating elements and the while point of installing it was to see if it would heat water for the cabin shower and kitchen.

In heat pump mode, it uses approximately 550 watts at 220 volts or about 2.5 amps (Amps x volts = watts).

I purchased this on sale at Lowe’s and also got a veteran’s discount, so my net price for the unit was around $800 - as far as I can recall.

It was a fun project to see if my array and balance of system could power it.
Thanks for the info!

My water heater is 13 years old. I have tried to drain it a few times, but the drain is plugged. I began to wonder how I was going to handle getting it drained, then I thought to drill a big hole into the side and put a hose in and siphon it out. Probably next week or two I'm replacing mine also!
 
I'm thinking of using the AOSmith Energy Star rating is $149/year but I plan on installing radiant floor heat and run it on solar.

With the $149/year under normal use how much more will it take for the floor heat?

How big of a solar array will I need? How many batteries ah will I need?
 
I'm thinking of using the AOSmith Energy Star rating is $149/year but I plan on installing radiant floor heat and run it on solar.

With the $149/year under normal use how much more will it take for the floor heat?

How big of a solar array will I need? How many batteries ah will I need?
Why not use actual Solar Water Heater Panels, not Solar PV panels? Solar Water Heaters are still extremely effective at making 140°F water.
 
Why not use actual Solar Water Heater Panels, not Solar PV panels? Solar Water Heaters are still extremely effective at making 140°F water.
How much water would I have to heat to last thru the night?
It don't get that cold in TN. but my whole body hurts if I wakeup cold.
 
How much water would I have to heat to last thru the night?
It don't get that cold in TN. but my whole body hurts if I wakeup cold.
Solar water heaters use the same basic system for hot water storage as any other water heater. Do you use up all your hot water every morning?
 
Solar water heaters use the same basic system for hot water storage as any other water heater. Do you use up all your hot water every morning?
I don't have hot water YET I don't have running water yet.
 
Water heater would have to be outside heated area as it will suck heat out of the heated area. Depending on outside temps it could reduce any expected gain.
 
Water heater would have to be outside heated area as it will suck heat out of the heated area. Depending on outside temps it could reduce any expected gain.
Every application and use is different.

In my case, I installed the GeoSpring hybrid heat pump water heater in the crawl space below our cabin. By doing so, and running the condensation drain house from the unit outside, I am able to keep the crawl space cool and dry in the warmer months in the mountains of western Arkansas.

The heat pump extracts heat and moisture from the unconditioned crawl space. During the cooler months, it does the same thing and so there may be some heat loss into the cabin from the earth below as the heat pump uses the relatively constant temperature in the crawl space. The cabin floor over the crawl space is uninsulated to take advantage of the moderating temperature of the earth below.

On the positive side though, my crawl space has a heavy sheet of vinyl covering the dirt and even though I had to dig a hole in the crawl space deep enough to contain the water heater, overall, it works fine.

One time, I had a service worker go into the crawl space to install a propane line for my fireplace and kitchen stove. He called his co-worker to come and look at the crawl space and said it was one of the cleanest and driest crawl spaces he’d ever seen. I store a lot of tools and supplies down there and the moisture reduction benefit provided by the heat pump water heater has given me a good and additional storage space.

As I recall from when I installed the unit, GE had a cubic feet requirement of air space for the installation area that was needed to insure enough of an air source for the unit to do its job. Overall, a fun project!
 
They output cold air. Keep this in mind when locating one in your home. Basements are a good location for them, as they dehumidify spaces. Winter time, can be a challenge, but the insulation of the tank is usually high, and they don’t run all the time, so the heat loss is handled by the earth and the heating system of the home.
If off grid, replace the element with a light bulb or the huge 5Kw element will rapidly drain your batteries...
 
The Rheem/Ruud will go into my house when the existing gas water heater leaks, the basement feels to humid to me one day or a thousand dollars is hanging around. My net meter just went three days ago. Seems I might as well send my excess power to the water heater and trim 15-20 bucks off my gas bill as opposed to selling the power back to the utility at 3 cents a KW. Looking at the efficiency of the Rheem unit it will not put much of dent in power sold back.

Our basement is a bit humid here due to the grading around the house and air leaks. My wife wants a cool place to store things. I am kind of wandering if the dry air these things discharge could be used to dry tomatoes or something. This water heater also displaces the cost of a dehumidifier. The house would look just a little prettier without that flue pipe coming out of the roof.

On the down side there is the noise. A cold basement in the winter. From what I have read, maybe it will be 55 degrees down there instead of 60 or something. So the gas heat does run to heat the first floor, but some of the test cases on these water heaters seem to say that the heat from the below grade concrete walls/earth. An unfinished basement tends to be near ground temperature regardless of the HVAC system.

Supervstech suggestion to put a light bulb in place of the element makes sense. I have been trying to figure out if the 15 amp model or the 30 amp model makes more sense. The Rheem literature says that the 30 amp model will use 161 dollars worth of power a year and that the 15 amp will use 110 dollars a year. The 30 amp has a 3.7efficiency rating and the 15 amp has a 3.55 efficiency rating. Could just be you put in heat pump mode and both models run the same. If anyone can help me out with the logic of one amperage over the other...............................................pulling 10 gage or 12 gage wire from the panel 15 feet over to the water heater makes no difference to me. Maybe the 15 amp model would go with battery back up nicer or have a heating element that is easier to bypass with a light bulb.

The company I work for is a Ruud dealer so I try to talk people into one once in a while. I have yet to be successful. Even the Wine people, humid basement people and the All electric people have yet to bite. Apparently an extra 600 bucks does not make sense to most people. LOL
 
You can buy vent attachments and probably vary where you send the cold and whre you pull the heat from.

The dollar estimates are based on some rate assumption that was significantly below my California rates. Also if you are on TOU rates there are ways to bank generation at high rates and then draw down the kWhrs at less expensive times. Finally, I put a mixer valve on mine so water leaving tank is never hotter than 110 degrees but have tank set at 125 degrees to store energy and shift loads. We are a household of two and never have to worry about having enough hot water.
 
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