Unpressurized Storage during the Off-Season

[Marshy]

What do folks do with their unpressurized thermal storage systems during the off-season?

I guess what I'm really asking is, if I don't want to use my system to heat domestic hot water through the summer will the water grow bacteria and algae if a minimum temp isn't kept?

I have a GeoSpring DWH and yesterday was the first time I put more than a minute of thought into the idea of what I will use for domestic hot water heating during this coming summer. If in use my boiler and Solartechnics tank to heat my 50 gal indirect then my GeoSpring sits idle (which means no cooling or dehumidifying for the basement, plus all the money I paid for it ). If I use my Geospring then what do I need to do to the water in the storage tank?

 

[NateB]

I use a heat pump to heat my solartechnics tankfor DHW. I dehumidify and cool the basement and get hot water. You may be able to do the same thing with you geospring. You may want to ask Tom.

 

[Marshy]

I use a heat pump to heat my solartechnics tankfor DHW. I dehumidify and cool the basement and get hot water. You may be able to do the same thing with you geospring. You may want to ask Tom.

Is your heat pump a ground thermal couple or an air to water heat pump?

 

[Fred61]

My unpressurized tank just sits there all summer. I don't have the slightest idea what's going on in there. Never looked! Bringing up the subject makes me wonder though. Perhaps I should inject a little chlorine in there before I dismantle it this summer, Yuuk. Don't know if the max temperature of 185 that it reaches during use is enough to kill 10 years worth of bugs. Water in the sight glass looks nice and clear.

 

[Marshy]

Huh, interesting. So you don't heat your tank in the summer @Fred61? Howe many years have you done this? And you have an American Solartechnics tank also?

 

[Fred61]

No, I have a cylindrical stainless steel retired chemical tank. 500 gallons.
I heat my DHW in the summer with a Nyle heat pump hooked up to my Super Store on my oil boiler.
The stainless tank was installed in 2008. I think I'm on my forth year on the heat pump. Before that my DHW was heated with oil in the summer.
Too much heat emitted from 500 gallon insulated tank in he summer.

 

[TCaldwell]

Garn recommends that heating storage about once every 6 weeks to 185 during the summer should be good, so far it’s worked for me

 

[tom in maine]

NOOOoo, chlorine! Tanks that sit idle usually are fine just sitting there. Once they heat up, any biologic activity will be knocked down.
If you feel the need to add something, never use bleach or chlorine. It might affect the liner or heat exchangers.

This is a non-issue for any tank that is idle in the summer. If you are really concerned about it, hook up a heat pump to the tank and store
DHW during the summer.

 

[NateB]

Is your heat pump a ground thermal couple or an air to water heat pump?

It is air source. I got one from Tom.

 

[Marshy]

@tom in maine, thanks for the advice.