New 120-Volt Plug-In Heat Pump Water Heater Is One of the First in the Country

HydroNiCK

https://cleantechnica.com/2023/10/25/our-new-120-volt-plug-in-heat-pump-water-heater-is-one-of-the-first-in-the-country/amp/

Derheatmeister

Thats great,but..You are probably voiding your warranty by not having a thermal expansion tank to protect the waterheater
BTW This forum does not allow discussing Pricing.

WMno57

Interesting Blog. More here on the house in Cleveland that now is the home of the 120v HPWH. Apparently it is also an Air BnB (with undersized outdated electric). Think I'll stick with Holiday Inn.
https://decarbonizeyourlife.com/home/f/cleveland-duplex-the-all-electric-side-costs-less-than-gas-side

Hot_water_fan

Think it's a great concept - with enough storage, there's enough hot water to go a long way. Great for fitting onto a 100 amp panel.

WMno57

I don't know. Seems short sighted to me. At some point the electric service to the home should be updated.

Hot_water_fan

If you're safe at 100 amp service, why bother?

WMno57

"but a recent kitchen remodel conveniently left a spare electrical wire to which we wired a 120-volt receptacle. We tested the circuit to confirm there weren’t any other large electrical loads on it."



Air BnB. Would you like to be the next door neighbor?

Hot_water_fan

Oh I'm speaking generally, not to the blog. I've only read the linked post, not the rest of the blog. I think a 120V shared circuit HPWH certainly fits a need.

WMno57

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.
I like 240v because it spreads the load across both legs. One neutral. Less copper.
120v HPWH would be good for an off grid home. Or, any home (on or off-grid) that has 120v solar and battery system.
In my opinion, an Air BnB should be held to a higher electrical code standard.

ChrisJ

WMno57 said:

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.
I like 240v because it spreads the load across both legs. One neutral. Less copper.
120v HPWH would be good for an off grid home. Or, any home (on or off-grid) that has 120v solar and battery system.
In my opinion, an Air BnB should be held to a higher electrical code standard.

A 240V single phase circuit has the same amount of copper is a 120V, no? Two hots and a ground vs 1 hot 1 neutral and a ground?

pecmsg

ChrisJ said:

WMno57 said:

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.
I like 240v because it spreads the load across both legs. One neutral. Less copper.
120v HPWH would be good for an off grid home. Or, any home (on or off-grid) that has 120v solar and battery system.
In my opinion, an Air BnB should be held to a higher electrical code standard.

A 240V single phase circuit has the same amount of copper is a 120V, no? Two hots and a ground vs 1 hot 1 neutral and a ground?

The wire size can be smaller.

ChrisJ

pecmsg said:

ChrisJ said:

WMno57 said:

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.
I like 240v because it spreads the load across both legs. One neutral. Less copper.
120v HPWH would be good for an off grid home. Or, any home (on or off-grid) that has 120v solar and battery system.
In my opinion, an Air BnB should be held to a higher electrical code standard.

A 240V single phase circuit has the same amount of copper is a 120V, no? Two hots and a ground vs 1 hot 1 neutral and a ground?

The wire size can be smaller.

I have no idea how I missed that.
That's embarrassing.

Hot_water_fan

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.

Not that I've seen, but that'd be great. There are A2W which do, but uncommon.

I like 240v because it spreads the load across both legs. One neutral. Less copper.

Agreed, but this is for existing outlets.

In my opinion, an Air BnB should be held to a higher electrical code standard.

Absolutely. A lot more regulations needed.

pecmsg

WMno57 said:

Does anyone make a combined A2A heat pump and HPWH? It would use a single 240v breaker. And be Grid Aware. That might be a good fit for this Cleveland duplex.
I like 240v because it spreads the load across both legs. One neutral. Less copper.
120v HPWH would be good for an off grid home. Or, any home (on or off-grid) that has 120v solar and battery system.
In my opinion, an Air BnB should be held to a higher electrical code standard.

The codes lag far behind the times!

EBEBRATT-Ed

People think if you have an appliance of some sort that has a 15amp attachment plug and a cord that it is legal to plug it into any 15 amp (or 20 amp) outlet.

This is not true.

It is true that you can plug in any appliance into a 15 amp outlet that has a 15 amp cord and plug if it is some type of PORTABLE appliance. An appliance that come with a 15amp plug is assumed to draw less than 15 amps so you can plug anything into a 15 amp outlet and being portable it is usually short term use and the code does not consider this a hazard.

But how many houses are burned down by the use and overuse of space heaters? Plenty.

A FIXED appliance plugged into an outlet cannot be rated for more than 50% of the circuit rating. So legally a window ac drawing 7.5 amps or less can be run on a 15amp general use bedroom outlet even though this may or may not be a good idea.

Any appliance that takes more than 50% of the circuit rating must be on it's own circuit.

ethicalpaul

Interestingly, they have options for dedicated circuit and for shared circuit. Maybe only the dedicated circuit one has a small resistive element...I don't know

Hot_water_fan

The plug-ins offered have both dedicated and shared circuit options. The shared circuit option has a compressor with a much smaller output compressor, hence the need for larger storage. For example, the shared circuit Rheem is 4200btu/h, so the amps needed are tiny.

ChrisJ

EBEBRATT-Ed said:

People think if you have an appliance of some sort that has a 15amp attachment plug and a cord that it is legal to plug it into any 15 amp (or 20 amp) outlet.

This is not true.

It is true that you can plug in any appliance into a 15 amp outlet that has a 15 amp cord and plug if it is some type of PORTABLE appliance. An appliance that come with a 15amp plug is assumed to draw less than 15 amps so you can plug anything into a 15 amp outlet and being portable it is usually short term use and the code does not consider this a hazard.

But how many houses are burned down by the use and overuse of space heaters? Plenty.

A FIXED appliance plugged into an outlet cannot be rated for more than 50% of the circuit rating. So legally a window ac drawing 7.5 amps or less can be run on a 15amp general use bedroom outlet even though this may or may not be a good idea.

Any appliance that takes more than 50% of the circuit rating must be on it's own circuit.

I'm fairly confident fires caused by 1500W space heaters are either from defective (loose contacts) receptacles, or cheap power strips. There seems to be no lack of either out there unfortunately. If the circuit is overloaded the OCP should protect against that.

WMno57

ChrisJ said:

If the circuit is overloaded the OCP should protect against that.

Can't rely on that alone. Too many 50 year old breakers in humid basements that haven't moved in 40 years.
Breakers should be switched off and on at least once a year per Square D.
https://www.se.com/us/en/faqs/FA127451/
Some recommend breakers be replaced after 20 to 40 years.
https://www.thisoldhouse.com/electrical/21016223/how-fuses-and-circuit-breakers-work

I saved the best for last. Check this out:
"The Consumer Product Safety Commission (CPSC) is a standard that estimates the expected life of consumer products. According to the CPSC, electrical breakers can last between 30 to 40 years. Other standards specify 30 years as the expected life span of circuit breakers.
However, an electrical breaker can serve you indefinitely if properly installed, not overloaded, and if there are no electrical problems in your area. You may never have to replace your electrical breaker in this situation.
However, this is under ideal conditions, and we all know ideal conditions don’t exist. If your area has issues like frequent power outages, power surges, lightning strikes, etc., your breakers will need to be replaced in due time.
More modern arc fault and ground fault circuit breakers have built-in sensors that detect either arc or ground faults (some combo breakers monitor both) in the electricity flowing through the circuit.
The problem with these breakers is that the sensors don’t last as long as the breakers. Once the sensor fails, the sensor no longer performs as intended and will no longer monitor and trip the breaker when an arc or ground fault exists. The breaker loses this protection and reverts to being a standard breaker.

The sensors inside CAFCI, AFCI, or GFCI breakers typically fail in 15 to 20 years, at which point an
electrician should replace the breaker.
You should perform testing of CAFCI, AFCI, and GFCI breakers monthly. Testing involves pressing the breaker’s TEST button and resetting it when it trips. The sensor has probably failed if the breaker doesn’t trip when tested, and you should replace the breaker.
https://homeinspectioninsider.com/circuit-breaker-replacement/

pecmsg

Depending on the refrigerant used with 115 Volts a 1/2 or 3/4-HP compressor is max for that system with a dedicated 15-amp circuit. Not a lot of heat recovery with that small a system.

Jamie Hall

There are so many reasons I like fuses...

pecmsg

Jamie Hall said:

There are so many reasons I like fuses...

Are they still allowed? I know there grandfathered in older homes but newer homes, something in the last 50 years?

Now im feeling old!

ChrisJ

@WMno57

I didn't know you were expected to exercise breakers. That's good to know.


Makes you wonder how many main breakers out there won't trip..........

Jamie Hall

Fuses aren't allowed in modern residences or most commercial buildings. More is the pity. There are just too many ways that people can mess them up. One is putting a bigger plug fuse in than intended -- although there are readily available sockets which prevent that. Another is jamming a penny in the bottom of a plug fuse socket. If you have cartridge fuses, you can always jam a piece of wire across the clips when the fuse blows. And so on.

Never underestimate the ingenuity of an idiot...

On the other hand I've never known a fuse to not blow when intended. And, on very old fuses, sometimes when not intended.

Further, there is an amazing variety of fuses for various protections. Slow blow for high amperage motor starting (with varying time/current ratings), normal fuses... fast blow for more sensitive applicaitons... ultra fast blow for highly sensitive electronics... and so on.

Cedric's home is still mostly fuses, and when electricians or building inspectors or insurance types show up they either can't figure out what they are looking at or go into hysterics...

ChrisJ

Can anyone find actual requirements for this water heater?

In response to previous concerns in this thread I tried to find actual specs.

All I've found is 120v 15a but I find it hard to believe it actually draws 15a with that plug on it.  Maybe that's more of a sales "this is all you need" type thing rather than actual draw?

I mean, some toasters do or at least very close but that's very intermittent.

pecmsg

As I said earlier 
15 amp minimum  20 amp model will have a 3/4-HP Compressor

ChrisJ

pecmsg said:

As I said earlier 
15 amp minimum  20 amp model will have a 3/4-HP Compressor

So that 15A ocp is centered around starting current, not actual steady consumption I assume.

pecmsg

ChrisJ said:

pecmsg said:

As I said earlier 
15 amp minimum  20 amp model will have a 3/4-HP Compressor

So that 15A ocp is centered around starting current, not actual steady consumption I assume.

15 amps is the safety. All appliances hooked up to that circuit should not exceed 80% of that or 12 amps total load.

Hot_water_fan

If the output is 4200 Btu and the COP is 3, that gets you a 1/2HP motor 

hot_rod

The latest Idronics has some great info about maximizing hpwh

https://idronics.caleffi.com/sites/default/files/magazine/file/idronics_33_na.pdf

A handy formula for operating at elevated temperatures.

SuperJ

HydroNiCK said:

https://cleantechnica.com/2023/10/25/our-new-120-volt-plug-in-heat-pump-water-heater-is-one-of-the-first-in-the-country/amp/

Thanks for sharing, it's good to see some more flexible options on the market. There are edge cases where 240v isn't feasible even if it is preferred. And you could run this one off a fairly small generator if need be. I'm looking forward to standalone heat pumps (separate from the tank). Like the Nyle Geyser used to be. Would be a nice way to retrofit some HP capacity to a electric tank.

dko

Spec sheet attached for the rheem,

note the GPH rise is shown at 60 degrees and not the traditionally used 90 degrees to make the numbers look better than they are in quick comparison.

These were released and were already being installed last year but then they stopped shipping for whatever reason. Recently started reshipping.

Most traditional households would be fine with the stored hot water anyway. peak morning and evening.

ChrisJ

@dko

With 3 kids and 2 adults I don't think it would work in my house.  A 50 gallon 40k btu gas does good but without that recovery it wouldn't cut it.

What's considered a traditional household?

EdTheHeaterMan

Jamie Hall said:

There are so many reasons I like fuses...

You were around when they were invented? LOL

I wish my new home had Natural Gas... I love the soft glow of a gas lamp when I'm sitting in my rocking chair, watching the Wireless. EDIT The Wireless is what they used to call the AM radio that was in the living room of the wealthy back in the day.

Eventually us peasants could afford them.

DJDrew

I am always impressed with the savings listed in these comparisons. The cost of our 50 gallon gas heater is practically free (a couple of bucks a month essentially) ... its the customer charge from the utility is what is actually costing us money in the summer months. For my house hold to achieve a savings by moving to this product, we'd have to get rid of all the gas use in the house... even then I'm not sure it would be saving money unless we had solar to knock down the electric rate.

EdTheHeaterMan

DJDrew said:

I am always impressed with the savings listed in these comparisons. The cost of our 50 gallon gas heater is practically free (a couple of bucks a month essentially) ... its the customer charge from the utility is what is actually costing us money in the summer months. For my house hold to achieve a savings by moving to this product, we'd have to get rid of all the gas use in the house... even then I'm not sure it would be saving money unless we had solar to knock down the electric rate.

As someone who was in the marketing business (I was the marketing manager for my one man HVAC company in 1978) I will always select the statistic that best proves my point. So when the Government requires me to put an "ENERGY GUIDE" on a water heater I want to manufacturer, I take the published national average number for the lowest Gallons of Hot Water used per year demographic, and select the lowest Average Fuel Cost nation wide that I can find, hoping that it does not include any of the really high priced markets, then I do a little magic with my calculator and tell you the my water heater will only cost you $50.00 a year to operate, then in small print somewhere I tell you that your actual cost may vary.

It how the game is played.

Fun Fact: Did you know that 47.6 percent of statistics are made up? I just made that one up.

Jamie Hall

there are lies, d___ed lies, and statistics. Mark Twain (I think)

ratio

There's a little book, called "How to lie with stastictics". It's quite dated now, but it's a real eye-opener and of course the math hasn't changed. I recommend it.

bburd

Jamie Hall said:

there are lies, d___ed lies, and statistics. Mark Twain (I think)

I thought it was Mark Twain quoting Disraeli, but no:

"According to The Phrase Finder, the earliest known citation of the expression in close to its current form is by Arthur James Balfour, 1st Earl of Balfour, as quoted in the Manchester Guardian, 29th June 1892: "there are three kinds of falsehoods, lies, damned lies andstatistics."