Solar thermal for hot tub

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Joeboy
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Solar thermal for hot tub

#1

Post by Joeboy »

I've got a chance at a couple of basic solar thermal panels?(Copper, glass ally frame insulated etc). Has anyone used on their hot tub?
Last edited by Joeboy on Wed Feb 08, 2023 1:59 pm, edited 1 time in total.
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Re: Solar thermal for hot tub

#2

Post by Mr Gus »

Donut of delite? ..where is our sarf country shed contingent these days Speccy-wan / aka Gravy Miner & monsieur Frotter ?
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Stinsy
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Re: Solar thermal for hot tub

#3

Post by Stinsy »

I think the unanimous opinion is that PV and a diverter beats ST these days. There are also some intrinsic problems with ST. Eg: if the water boils it can be dramatic, all liquids leak eventually, all moving parts (pumps) fail.

However if you really want to mess around with ST I don't imagine it'd be too difficult to hook some tubes to the existing circulation pump just for the shits and giggles.
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Joeboy
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Re: Solar thermal for hot tub

#4

Post by Joeboy »

Stinsy wrote: Wed Feb 08, 2023 2:02 pm I think the unanimous opinion is that PV and a diverter beats ST these days. There are also some intrinsic problems with ST. Eg: if the water boils it can be dramatic, all liquids leak eventually, all moving parts (pumps) fail.

However if you really want to mess around with ST I don't imagine it'd be too difficult to hook some tubes to the existing circulation pump just for the shits and giggles.
That's, kind of what i'm hoping to do. I played about with this offshore once and Billy the kid was right, can get a good heat going. The guys wanting £50 for 2 panels 1350x850,85.
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Moxi
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Re: Solar thermal for hot tub

#5

Post by Moxi »

you cant refuse at 50 quid theres plenty of useful stuff you can do with them

Moxi
ALAN/ALAN D

Re: Solar thermal for hot tub

#6

Post by ALAN/ALAN D »

I have taken 3 Naviwatsit ones of my roof and next door. Fitted years ago.
In a house possible pump / leak problems.
On a hot tub outside not so much of an issue apart from.
Pump costs.
To replace / Pump electric running costs.

Fit P.V. Panels directly wired into immersion heater.

Manifolds / Thermal tubes in ESSEX can be picked up for nowt if required.

P.V. Fit and forget.
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Re: Solar thermal for hot tub

#7

Post by Moxi »

I used to have the other place evac tubes with integral tank, lost it when I divorced and I miss it enormously.

On days where the insolation was negligible for PV power generation the tubes just accumulated more and more heat from the grey overcast skies.

Through the winter the hot water was used for washing pots, cleaning cars, keeping seed trays warmed etc in the summer paddling pools and a host of other stuff, never used pumps it was all done with mains pressure, never had a leak either and for that matter if we are so leak averse why do houses have wet central heating and internal water supplies often with big heat store tanks ? I had a hot water tank that leaked once after thirty years, I replaced it with another.

Its like everything isnt it, if the price is right and you have the space that's not required for anything else then its a goer, but if the space is limited and you want the best bang for the space then yes PV panels of equivalent size would be a better option, its down to the specifics of the individual and their wallet capacity amongst a gambit of other considerations.

Moxi
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nowty
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Re: Solar thermal for hot tub

#8

Post by nowty »

ALAN/ALAN D wrote: Wed Feb 08, 2023 2:15 pm Fit P.V. Panels directly wired into immersion heater.
Yep that works, but no thermostat. :twisted:
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Re: Solar thermal for hot tub

#9

Post by Moxi »

After that diatribe JB I would also point out that if its a pre heat you want for the hot tub then in the summer months when presumably your Battery stack is generally full would you no be better using a small immersion heater type set up to preheat the tub of delight from the overnight cheap slot electrickery ?

Moxi
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Joeboy
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Re: Solar thermal for hot tub

#10

Post by Joeboy »

Moxi wrote: Wed Feb 08, 2023 3:02 pm After that diatribe JB I would also point out that if its a pre heat you want for the hot tub then in the summer months when presumably your Battery stack is generally full would you no be better using a small immersion heater type set up to preheat the tub of delight from the overnight cheap slot electrickery ?

Moxi
Oh absolutely, it's very much 'just because you can doesn't mean you should'. Totally aware of that. :D Nonetheless...

I'd love to be able to for example build a standalone outdoor shower. I'm just messing about in my mind, nothing serious. Seem to be a bit caught on the mental🪝 of 'what if' re the grid dropping out. A solution that would provide hot water thus preserving the PV generated power and not use it to heat water would be good. Ach, oh no, thought, arggghhh new woodstore roof! :shock:
19.7kW PV SE, VI, HM, EN & DW
Ripple 7kW WT & Gen to date 19MWh
42kWh LFPO4 storage
95kWh Heater storage
12kWh 210ltr HWT.
73kWh HI5
Deep insulation, air leak ct'd home
Zoned GCH & Hive 2
WBSx2
Low energy bulbs
Veg patches & fruit trees
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