Planning to install 220 electrical outlet

Gotcha! okay that makes a lot of sense.

We recently did the last phase of a big electrical upgrade in our house. We replaced an antique subpanel, and in doing so created a lot more space for future expansion to utilize the full 200A service we've had all along.

So I'll probably go for a unit that has the resistive heaters installed. I've got a basement with a big airspace, great place to put the thing next to the sump and only maybe 15' from the breaker panel. The only weird thing I'm doing is adding valves to select between that water heater and my oil loop.

I want to maintain the oil loop system because A) I don't want to dismantle or disturb it and B) when the power goes out I can make all the hot water I need out of the oil system powered by my generator. The genny is too small to run the resistive heaters and I probably won't run it full time, so the HP can't benefit.

 

Many customers do have different constraints. While this item is not good for many customers, I do believe that it and similar can pick up a very substantial portion of other customers who want to retrofit but are blocked or deterred from the usual 240V offerings.

 

If I remember right, availability of some rebates or incentives might be diminished if the HPWH is put in conditioned space, as you're then using your HVAC to put the heat in the space that the HPWH is taking back out.

 

This is where it is very important to distinguish between heating-dominated and cooling-dominated climate zones. In the former, putting an HPWH inside the conditioned space, without ducting the intake and exhaust, is counterproductive. In the later, it helps reduce the load on the cooling system, making a very nice 2-fer.

 

Its interesting to note Central Texas is in one of those "above 37f" in January areas and historically it has been warm enough that most plumbers installed gas fired tankless outside. With no serious problems since their introduction in 1999 by Rinnai. Until 2021, when a week long hard freeze ruined almost every one. Then another hard freeze in 2022 and again this year.

Now they have to go in a freeze protected garage (usually with a small electric heater) or inside the conditioned space. Meanwhile, conventional gas or electric tanked water heaters are typically in an unheated garage, ventilated attic space or inside, in a tight closet. Those installations had no issues as long as power to the device was maintained. So there are changing conditions impacting tankless water heater use.

 

I wonder if any type water heater should be put in an unconditioned space like a garage

I wouldn't be comfortable as a homeowner with a cold-water supply line in an unconditioned garage. Exactly for the reasons you mentioned about the units freezing up and having problems in colder weather.

Realize a gas heater with a standing pilot would have some residual heat it gives off in an enclosed closet as well as the tank of hot water giving off heat.

The thought of running a cold-water line in the garage seems to be asking for trouble when the once ever couple of years abnormal cold snap comes.

There are probably preventative measures like heat tape, insulation etc that would minimize the risk but I wouldn't do it. Power fails - pilots go out and cold snaps happen.

Still remember the stories about the water lines that were freezing in the attics and garages of Texans homes. Just doesn't seem like a best building practice. Even in our somewhat central America location there are water heaters put in the garage -they have to be in a closet with some type venting to the homes warm air - and more than a few of these units will still manage to freeze in severe cold snaps in uninsulated garages.

 

"Still remember the stories about the water lines that were freezing in the attics and garages of Texans homes. Just doesn't seem like a best building practice."

In most unincorporated parts of Texas (which means most of it outside larger city limits), building permits and inspections are not required except for two specific items, a driveway permit (gets you on the tax roll) and a septic permit (if needed). Combined with the historic minimal freezes until recently, it was cheaper to use attics and garages for mechanicals. Not all houses, but a big majority.

 

My house was built with the incoming water line traversing the length of the unconditioned garage before entering the crawl space, so I was already hosed on that issue. It did freeze and cracked a T-fitting during a severe cold snap our second winter here, when the house was three years old. Not an outright burst, but a hairline crack that slowly seeped water several days before being diagnosed.

After repair, I put a heat tape on it. And insulating hose bib caps on all the outside faucets, one of which was teed off the cracked fitting. Later, fully insulated the exposed pipe with thick (not more common thin) foam tubes. Later still, saved heat tape energy by putting it on a thermostatic outlet with an interval timer, as it didn't need to run full-time under all that insulation, or at all when the garage was above freezing.

Now that the water heater has been moved out there too (though up against an interior wall, not exterior), its pipe connections are similarly insulated.

A couple decades after that freeze leak, the new owners of our nearly identical twin house suffered a burst fire sprinkler pipe during a severe cold snap while they were away, causing severe water damage to a bedroom. My fire sprinkler pipes weren't all that well protected either, and less so after some unrelated attic work disturbed and thinned the insulation atop some pipe segments. (During one deep freeze, I tested the outdoor faucet at the sprinkler's far end, which betrayed a partial ice obstruction somewhere along the line, though quickly cleared by water pressure when the faucet opened.) That was additional impetus for upgrading our attic insulation. By doubling the original (undisturbed) thickness, essentially tripling the original thickness above the pipes, and removing all insulation just beneath the pipes to create a thermal bridge to the living space below (making little cardboard tents to keep insulation out of the gap), I figure those pipes are now well protected from freezing even during an extended power failure. We still have a wood stove for backup heat to keep the living space from freezing.

That attic project fixed several other deficiencies too, such as over 100 square feet of uninsulated ceiling, hidden where no inspectors would likely find it. That very significantly improved both winter and summer comfort.

 

Having fire sprinklers in a home seems like a great idea - does code require that in your area?

 

Heck, I wish I had hydrants nearby...

 

My house in dfw had a pvc water line from the street that was barely 6" deep (made it easy to DIY repair when it sprung leaks), the pipes for the house were uninsulated and run around in the crawl space under the house. Hot water heater was installed in the uninsulated garage, which didn't even have a garage door when we moved in. We didn't have any hard freezes in the 5 years we lived there. I expect the water lines were totally wrecked by the hard freeze in 21.

 

My house was required to have fire sprinklers specifically because the nearest hydrants were too far away. Sprinklers are not (yet) required within a certain hose-laying distance of a hydrant, which covers nearly all new construction next to the streets, but not some of the infill behind, on the interior of large blocks. Major developments generally prefer to install new hydrants as part of the new utility service.

Since most homes haven't been required to have sprinklers, the local industry isn't well developed, costs are high, and for a long time the local water and fire districts were in conflict over the issue, with the water district requiring larger meters and demanding higher capacity and monthly connection fees because of the higher water demands of non-sprinklered homes with the same larger meter sizes, never mind that normal-size sprinklered homes don't use any more water in normal use, but typically need 90% less water for fire suppression than non-sprinklered homes, which don't pay extra fees for that capacity from the hydrants. The water department also tried to retroactively forbid certain sprinkler topologies such as was installed in my house, approved by the fire department, and insisted on retroactive installation of a special backflow preventer valve requiring annual inspection fees, before finally backing off after hearings at the state legislature. (The water department industry had serious fractures within itself, with half of other districts working cooperatively with fire departments and the sprinkler industry. But I can't choose a friendlier water supplier, they all are local monopolies.) When I had a specific sprinkler issue, the fire department revealed a separate set of problems and incompetencies, and assumed homeowners had unlimited budgets to fund union featherbedding, while the local sprinkler installers at that time wouldn't touch any existing residential system, would only strip out the old system and design and install fresh, with design fees alone (not including materials and installation) exceeding what the NFPA insisted were typical total system costs.

It also didn't help that the original sprinkler design and permit and inspection paperwork are all missing. While all the other original property and home documents are readily available at the county land use office, the sprinkler documents were then required to be filed separately with the county Fire Marshall's office, which didn't have a competent document retention system, so everything of that era is now "lost".

My sprinkler problem remains unresolved, on the theory that it is better to let sleeping dogs lie until all the involved personnel at both the water and fire departments have retired or moved on. At last check, one more person remains.

 

Read the first ten posts skipping #9. The expensive and hard part is installing a 50 amp service from your main breakers to the car charging location. You may want two 50 amp in the future but one will suffice since it could be $2,000 by itself depending on distance and or if your whole house electrical service and breaker box has to be replaced to accommodate. This is a big variable that only an electrician or some training on your part can determine. Wire size for the same load varies by distance. Get a quote.

 

A minor point: service is a term of art and refers the connection from the serving utility to the building’s wiring, which you’d only need to change if it’s not large enough for the existing and added loads.

For EV charging, it’s a branch circuit that’s usually added. For Level 2 charging at up to 40 A, derated from 50 A because it’s a continuous load (per National Electrical Code 625.41, 210.19(A)(1)(a), 210.20(A)), you’d typically install a 240 V (2-pole), 50 A circuit, with a NEMA 6-50R receptacle outlet, GFCI protection (625.54, 625.60(D)), and no other outlets (625.40). The Code has other requirements; see Article 625, and of course, any state or local amendments.

As @rjparker kindly mentioned, the specific materials needed depend on many factors: whether the existing service and load center (panelboard) can accommodate the added load; the distance and conditions over which the branch circuit wiring will be run; and details such as whether the receptacle outlet will be in a wet location, requiring weatherproof protection (625.56).

 

If you have the room in your circuit panel I'd run two 50 amp lines. You'll need 4 circuit breaker spaces, each 50 amp line will need a dual circuit breaker. It would be cheaper to run 2 lines in one installation than pay for 2 installations. For placement I put the plug near the garage door on the inside and close to a window. That way I can charge any car inside my garage or outside on the driveway and my EVSE always stays safe inside. I also purchased an EVSE with the longest cord I could find which was 25'.

I know, why next to a window? Well when I sealed my driveway, I had to park my car on the lawn next to the garage. I simply ran the cord out the window and was able to charge it from there.

 

That's exactly what we did, totally worth it. Now... 6 years later... my spot will go from Prius Prime charging to bZ4X without any change. The same dedicated line will work as is.