Hello:

I was thinking of building a super-insulated enclosure for my hot electric water heater, which lives in my heated crawl space.

Is it worth doing this?

Does anyone see a problem with doing this?

Thanks,

Rob.

The heat it is losing to your crawlspace is created by electric resistance. What is the cost of that as compared to the method you use to regulate the heat in the crawlspace in the first place?

Hi ICFHybrid:

I'm not sure how to answer your question.

I think that you are saying that any heat lost from the hot water heater will simply help heat my crawl space. I use electric resistance heaters - baseboard heaters.

Are you saying that the total electricity bill for hot water AND heating the basement will be the same? Or, said another way, the amount of electricity not used by the baseboards will be the inverse of that portion of the electricity used to heat the water but is lost to the crawl space from the water heater?

Won't that be true only if I heated the water and the crawl space to the same temperature?

I don't think I understand your question or even my answer.

Rob.

It would be easier to explain that you will save some energy during the summer. But you should look at ROI and that is more complicated.

I think that you are saying that any heat lost from the hot water heater will simply help heat my crawl space

Exactly. Once the heating season is over, and the resistance heat is no longer needed, the heat lost by the water heater begins to cost you money, but that needs to be balanced against the cost of the blanketing and whatever other low hanging fruit you may have in that department.

Rob - you need to make sure the crawlspace doesn't drop below freezing and remember that the colder the crawlspace gets, the colder the main-floor floor will feel to your feet.
Having said that, there will be some saving by insulating the tank because the tank to crawlspace has a much higher delta t then the baseboards to main-floor air. The colder you normally keep the crawlspace, the more you would save insulating the tank. It might make cents to slip a jacket over the tank but you would not be talking a huge saving.

Thanks people!

My crawl space is heated and air-exchanged as is the single floored house above it.

The cubic feet down there is about 4800 cu ft.

There is no insulation on the ceiling of the crawl space so I will keep the temperature down there about the same as the house above.

I won't super insulate my hot water tank.

Rob.

I think it depends on the water heater. If it is warm to the touch consider it. if not, then there is nothing to be gained.