Powerwall mounted inside or outside?

[Tom Bradford]

Here in the sunniest part of New Zealand (>2800 hours sunshine annually) the outside temperature might touch 0'c four or five times a year and equally rarely exceeds 30'c. In the laundry - a utility room really, on the south side of the property - it's probably never within 5' of either. It's a simple place to get to with a cable from the panels on the roof while the inverter, Powerwall and gateway will all be within a meter of the distribution board and each other. Putting the Powerwall anywhere else is going to involve running conduits, making holes in walls, building sheds &tc.

So unless there's a local rule against it, that's where it's going - unless off-gassing is a problem. The laundry isn't air-tight but it's not deliberately ventilated either so there probably would be a build up of any gasses produced. The US and Canadian Regs referred to on p9 of the installation manual, and Ulmo's contribution above re Tesla's new thinking strongly suggests that there's no inherent dangers installing the Powerwall in a dwelling so I'm assuming it's OK.

 

[JohnRatsey]

So unless there's a local rule against it, that's where it's going - unless off-gassing is a problem. The laundry isn't air-tight but it's not deliberately ventilated either so there probably would be a build up of any gasses produced. The US and Canadian Regs referred to on p9 of the installation manual, and Ulmo's contribution above re Tesla's new thinking strongly suggests that there's no inherent dangers installing the Powerwall in a dwelling so I'm assuming it's OK.

There would be something seriously wrong with a lithium battery for it to emit gas and I would hope it would shut itself down long before that happened. It's just a somewhat bigger version of the battery in your phone and innumerable other devices.

The battery is a potential source of fire (as are other household appliances eg these) so a smoke alarm would give peace of mind if you haven't got one already and an additional precaution could be a fire-rated door between laundry room and the rest of the house. My PW is in the garage - didn't need any thought as that's where the solar inverter and other electrics were already located and it was easy to clear some space.

 

[Ulmo]

Here in the sunniest part of New Zealand (>2800 hours sunshine annually) the outside temperature might touch 0'c four or five times a year and equally rarely exceeds 30'c. In the laundry - a utility room really, on the south side of the property - it's probably never within 5' of either. It's a simple place to get to with a cable from the panels on the roof while the inverter, Powerwall and gateway will all be within a meter of the distribution board and each other. Putting the Powerwall anywhere else is going to involve running conduits, making holes in walls, building sheds &tc.

So unless there's a local rule against it, that's where it's going - unless off-gassing is a problem. The laundry isn't air-tight but it's not deliberately ventilated either so there probably would be a build up of any gasses produced. The US and Canadian Regs referred to on p9 of the installation manual, and Ulmo's contribution above re Tesla's new thinking strongly suggests that there's no inherent dangers installing the Powerwall in a dwelling so I'm assuming it's OK.

I'll be somewhat pedantic:

• USA laundry rooms typically outgas the dryer's dusty humid air through a dryer vent. This can be especially bad for electronics if the vent falls off, and this is a common occurrence. In a multi-unit dwelling with a communal laundry room, laundry rooms turning humid full of damp dusty air is a usual occurrence. If this is a private home, then measures to avoid that would have to be taken, such as first it not having a communal multi-family nature, and second that the vent from the dryer both be as straight, short, and flexible as possible with secure connections as possible. That's a tough order, but typically it means smartly locating the out vent in a place that doesn't crimp a pretty high quality flexible hose that is unlikely to tear or puncture, and that the hose be able to easily secured strongly both to the dryer and to the exit vent, with easy access for service and repair and cleaning and replacement. If all of that is true, then servicing the hose, vent, and dryer should not result in leaving the hose disconnected or punctured, and the likelihood of the room becoming humid then relates to the airflow of the outside vent and whether it gets blown by wind back into the cracks of the building, which if it's not upwind of everything else shouldn't really happen. Basically, a nice cleaning and good workmanship of good materials on the dryer vent should be performed prior to installation of PowerWalls, and if the original installation was good, that should be enough for that step. I have no idea what JHA (jurisdictions having authority) would say about that, but it seems like common sense. The PowerWalls are rated for a certain level of water, but not constant humidity of the likes of the output of a dryer vent. If anything, the dryer room might naturally bring in some fresh air into the washer room in a way that helps the PowerWalls, if the laundry room's makeup air input (via whatever natural means) is generally upwind of the dryer output. Even a small leak in the dryer vent inside the laundry room, especially if it is a long run, would tend to void anything I said about it being appropriate, but the remedy of that is fairly straightforward vent plumbing. I've even seen assistance fans that help dryer vents negative-air-pressure the dryer vent that electronically turns on the same time the dryer turns on that could help alleviate long vent run concerns and solve some punctures or leaks as well, but those have to be properly tuned and sized and such to exactly match the needs of that particular vent run for that particular dryer.
• Most USA garages are leaky in terms of air, in order to clean out the rabid chemicals of ICE cars, and those chemicals are not allowed to enter any area of the lived-in property as a result. I think the gases from PowerWalls are a lot safer than those from ICE cars, but make sure the only places the PowerWall vents to are places where air already leaves (such as kitchens, bathrooms, part of the hallways, etc.) before wafting through continual living spots, i.e., at least make sure the PowerWall fumes, however slight, never collect around the bedrooms or living rooms. They are not like lead acid batteries that put out toxic explosive hydrogen; I presume they're just the typical chemicals put out by electronics.

That might sound like a lot of talk, but in practice, it's no more difficult than any other PowerWall installation when all is said and done. I should caution that if anything I said is causing you to think of expensive solutions to venting, you're probably barking up the wrong tree. Most of what I talked about should be relatively modestly priced. Only if the laundry room is upwind of the rest of the house and doesn't naturally vent out its aires and it already contaminates the bedrooms and/or living rooms should it need additional venting, and that additional venting hopefully would just be as simple as another hole in the wall, weather venting, and the tiniest of fans put on a relay with an electricity sensor wired to the dryer somehow (be sure to unplug the dryer before working on it) to make sure said fan only blows when the dryer does not. Basically about $75 in parts or so, plus or minus. You would need JHA approval, of course. Your Tesla engineer might have a word to say about that.

 

[abasile]

at least make sure the PowerWall fumes, however slight, never collect around the bedrooms or living rooms. They are not like lead acid batteries that put out toxic explosive hydrogen; I presume they're just the typical chemicals put out by electronics.

The Powerwalls should not be emitting anything at all; the fans are merely for heating and cooling. I suppose there could be a tad of off-gassing from the materials themselves, much as "new car smell" arises from the off-gassing of VOCs (volatile organic compounds) from the materials in a new car.

The principal reasons to keep Powerwalls away from bedrooms are that some people might find the fan noise to be bothersome, and that lithium ion batteries do add some fire risk (though it should be only a very slight risk with well engineered battery systems).

 

[Janus]

At least in the US, the wall (and door) between the garage and the rest of the house has to be fire resistant. The thought being, ICE cars have always been flammable, and people tend to store stuff they shouldn't (i.e. propane) in their garage.

So installing the PowerWall in the garage, would offer better fire protection, than an interior room (like a laundry).

Though garages tend not to have smoke detectors (due to false positives from ICE cars). But if someone is only planning on putting an EV into the garage, adding a smoke detector there might not be a bad idea.

 

[Tom Bradford]

t least in the US, the wall (and door) between the garage and the rest of the house has to be fire resistant.

Not so here. Probably because until only a few years ago most houses here were of timber construction so a fire resistant door would merely be the last piece of the building to catch fire if the garage did. Not that I've heard of that happening often enough to be a serious concern.

We don't have a dryer, in the laundry or anywhere else. We have a bit of string between two posts n the back garden to serve that function. So humidity isn't likely to be a problem. Mind you, I would have thought a Powerwall mounted outside in a foggy UK November morning would face far more problems with humidity.

ANYTHING electrical poses a fire risk, but Powerwalls don't seem to have gained a reputation for bursting into flame, so in the absence of any official no-no in NZ and what I've learned here concerning the absence of predictable hazardous emissions, putting the thing in the laundry/utility room is otherwise so convenient that I think I'll go for it. A smoke alarm and a convenient suitable fire extinguisher to hand would seem to be sensible precautions, tho'.