5 replies to this topic

[Shane_H]

Hi All,

I'm in the process of having my pond set up with solar heating similar to what you would find for swimming pool solar heating systems (ie water pumped up to black medium on a roof and circulated back down to pond).

Any idea what size/head lift pressure pump I would need for this to work effectively?

Thanks,
Shane.

[sidecar66]

For swimming pool solar we tend to put 1hp pump for 2 storey houses and 3/4hp pump for single story but alot of people are starting to go as low as 1/2hp solar pumps for single story houses with a 30 000L pool. the reasoning for that is the slower the water gets pushed through the warmer it gets so the pump with have to run less to get where the temp needs to be, where as higher hp pumps you push the water through alot quicker so doesnt have time to heat up there for needs to run longer to get the same temp

It also comes into how far away roof is, how much matting on the roof and pond size. Being a pond you might also opt for a swimming pool pump with the hair and lint basket to catch alot of the stuff that would normaly block the impella rather than a solar pump which does not. they are the same motors the only difference is the pool pump has a basket and solars dont.

i hope that makes sence and im not just rambling on

[sydad]

If you have a "closed" system: that is one where the water is returned to the starting point, all that is required is a hot-water circulation pump. The only problem that may occur would be the presence of an overheat dump valve, but this may not significant if you have a single story dwelling, as such pumps have sufficient pressure to restart systems provided the dump valve also has a pump switch.

Syd.

[Buccal]

There is a place in Belmont, but not sure if it's still going.
Check them out, a place called Allcontrols.
It's important all parts needed are used.
Water becomes hot enough to scald your skin, so thermostats, valves so on with advice to get job done right.
If water is pumping from pond up to the heating device, a standard pump of anything can be used but going by its head height abilities.

[Shane_H]

Thanks guys.

It will be pumping form pond up to shed roof (so ~2.5m - 3m head). I'm thinking of just getting a submersible pond pump that can pump up to a 5m head but use a control valve to regulate the volume/rate of water flowing through the heating panels.

Do you think some sort of filtration between the dirt water pond pump and the solar panels is required? I'm thinking there is potential for chunks of solid pond material getting caught inside the solar panelling system.

I'm not planning on using any theremostat regulator. It wont be used in summer, only over the winter months where it will struggle to get warm enough. Just a simple, effective system.

Regards,
Shane.

[Buccal]

Best to keep them separate.
But be very careful.
You will need this a decent size to work and benefit mid winter.
But some days may catch out, and don't underestimate how well these work.
Especially into a small water body.
You Definetely want a thermostat control for piece of mind.
Hugal a Hoyle retic shop sells sensor probes ready for hard wiring.
Buy yourself a quality power multibox and take both probe and multibox to a sparky.
The probe can be connected to the wire of the multibox.
Anything plugged into multibox will switch of when water hits the set temp.
Labour and parts all up about $150.
I have the same thing with all my pumps in breeding room plugged into the multibox with probe.
But the probe I have is a level prob and not a temp probe.
The way you would run this is:
Add a addition cheap bunnings timer, the ones with those little push in tabs.
Set the 24 hour gauge to running pump for 5minutes then shut of for 20 minutes then run for 5mins then shut of for 20 mins and so on.
Obviously not running of the night.
The shut off periods let the water have enough contact time to the sun.
This will work better than you think, especially sunny winters.

In my set up level probe is so pumps don't run dry in sump if water is escaping somewhere, EG (busted tank).

Edited by Buccal, 14 January 2013 - 10:24 PM.