[MHElectric]

I have a 36 kw unit made by Eco Smart. It's in my own house I'm renovating. It's perfect since when I first installed it, I wasnt staying there full time so would be in and out randomly when I had time to work on the house. Didn't have to keep a tank unit on all the time and still had hot water as soon as I got to the house after not being there in days/weeks.

4 40 amp breakers, well water, and the elements turn on sequentially one at a time based on demand.
200 amp service, small 900 sq foot house. Haven't had any issue what so ever, lights don't flicker.
No access to gas on the property, everything in the house is electric, including baseboard heat. Installing a multi zone mini split currently. So far, I'm a fan of the on demand heaters. Time will tell. It's been the only source of hot water there for about 2 years. No breaker or bus issues what so ever.

900sq ft? Probably not an enormous amount of demand on the electrical system. That sounds like a small 2bd 1 bath, right? Maybe 3 people there, 4 tops.

Wonder what that would look like on a 1500-2000 sq ft home...

 

[Willie B]

Some laymen use the logic, "I got 220, why not. I won't have to buy gas."

The subject has come up a number of times. The only one who actually bought one wasn't all that sharp. His house was supplied by a 1940 vintage overhead service. A 15 KW transformer supplied 3 houses. His was supplied with an overhead service #4 aluminum. IIRC his was 127 amp load total in three stages. He saw no problem upgrading to 200 amp service until he heard the price. His 19 amp tank water heater started looking better.

 

[MHElectric]

Yeah, I agree. This is definitely not a cost effective installation. This is for people who have money to spend on something they want.

 

[nrp3]

It sounds like it could work out like it is for the poster if it has limited use and the installation was done correctly. I find it difficult to compare costs, payback and so forth when trying to compare fossil fuel vs electric heat or hot water. The practical aspect of the install sometimes seems to be the driver. I noticed that it's been a long time since the property managers converted from electric baseboard heat. I'm sure there are a lot of factors in that decision. Several conversions to gas have been done from oil, possibly driven by underground storage tanks.

 

[gpop]

Yeah, I agree. This is definitely not a cost effective installation. This is for people who have money to spend on something they want.

Poco in my area doesn't want anyone back-feeding solar so one option i have been looking at is to convert my hot water heater to 24vdc and using it as a pre heater. Then i could install a tankless water heater to finish heating the water before use.
The power requirement of a tankless unit does make you scratch you head and wonder if its worth the hassle.

 

[MHElectric]

Poco in my area doesn't want anyone back-feeding solar so one option i have been looking at is to convert my hot water heater to 24vdc and using it as a pre heater. Then i could install a tankless water heater to finish heating the water before use.
The power requirement of a tankless unit does make you scratch you head and wonder if its worth the hassle.

So to compliment your idea - there were several other models that the customer had looked at. They range in KW size.

I believe the KW usages is based on how many gallons per minute of usage you project to use.

 

[MHElectric]

A quick Google Search shows at least a dozen different electric models and brands.

Ranging from 11kw to 32kw.

In fact one site says electric is so much better than gas models because you don't have to pay for the expensive "gas piping and venting". Lol. That's right...

 

[Switched]

Why not one of those hybrid heat pump water heaters?

 

[MHElectric]

Why not one of those hybrid heat pump water heaters?

Never heard of them.

 

[Switched]

I had one customer put one in, he was converting to all electric in his home. They are supposed to be super efficient.

 

[former farmer]

What meter does the customer have? If it is a digital one, it may tell you the maximum demand that the customer used. This may be helpful to see if the service is large enough.


https://www.we-energies.com/residential/howto/read-meter.htm

 

[gpop]

Why not one of those hybrid heat pump water heaters?

They seem to have reliability issues and they cross the divide between something a plumber can fix or something that needs a air conditioner tech.

You can judge new tech by how many have been removed and are for sale on facebook. Common complaints are noise, lack of hot water and finding some one to service the unit.
Florida is the prefect place for these units as they are normally found in unconditioned garages where noise isn't a problem and the cold air being expelled is a bonus so its worrying that 10 are for sale locally (new tear outs).

 

[gpop]

So to compliment your idea - there were several other models that the customer had looked at. They range in KW size.

I believe the KW usages is based on how many gallons per minute of usage you project to use.

I have a messed up disk in my back so i tend to have 2-3 baths a day so i want lots of hot water. 40% of my electric bill is probably hot water so its less about cost and kw then it is about unlimited hot water.

Your customer may have taken something like this in to account so what seems overkill to you is perfectly acceptable to them.

 

[skyline77]

Usually, they are used for areas where there is no continuous use of water in order not to continue heating water all day long as done in a normal electric water heater.
In regards to the solar heater, there are two types of solar thermal and PV.
Solar thermal is preferred in hot climates as PV efficiency is very low in hot sunny areas and they don't need batteries.
In general, for a sandy area just be sure that they can be cleaned or oversize it, to consider the dust accumulation in case it's an issue.

 

[Willie B]

Why not one of those hybrid heat pump water heaters?

I installed one for my house. Consumption went from 500 KWH to 125. It dehumidifies the cellar, and cools it, very pleasant in summer.

 

[220/221]

I installed one with 2 50A/240V circuits 10 years ago, under the kitchen sink :jester:

I don't know anything except that it seemed like a very, very bad idea

 

[MHElectric]

I installed one with 2 50A/240V circuits 10 years ago, under the kitchen sink :jester:

I don't know anything except that it seemed like a very, very bad idea

220 - you are like the last of the cowboys. All brawn, zero cares.

 

[wcord]

Never heard of them.

AO Smith makes them

https://www.ecomfort.com/A.O.-Smith-HPTU-50N/p72555.html

 

[Switched]

What about having multiple point of use units located throughout the home, like maybe a unit per water location? Bath 1, Bath 2, Kitchen, Laundry?

Cost of installation aside, I wonder about the efficiency of the system, both on the water use side and the power consumption side.

 

[MHElectric]

What about having multiple point of use units located throughout the home, like maybe a unit per water location? Bath 1, Bath 2, Kitchen, Laundry?

Cost of installation aside, I wonder about the efficiency of the system, both on the water use side and the power consumption side.

Those small Insta-Hots are 240v 20Amp, aren't they? Usually they fit under a sink or something, can they handle an entire bathroom or kitchen?