Backyard Aquaponics
A place to discuss aquaponics

If you use the 90mm stuff the air will have more time to cool. I'm going to do a similar thing later when my other half is not looking. Bury 6 lenghts of 90mm. Hell if I'm going to dig I might as well bury twice as much.

For anyone who wants to see the strength of the Evacuated Tubes do a search on Youtube for evacuated tube collector. There are at least three vid's showing some company tests. One with a steel ball, one with a ball of ice and one stacking some weight on top of the tubes untill they break, impressive results. Seems they passed anything that would normally hit them in my area.
Rup, in your set up, do you think sediment from the tank will be an issue in the bottom of the tubes? Perhaps a maintenance issue dependent on where the water is taken from to feed the Evac's.

F&F is saying 100 metres of 25mm pipe. Much better than 90mm :-)

DL. Sorry not sure what your saying.
If you suck the hot air out of the roof cavity then cold air from outside would be sucked into the roof cavity. Therefore over a period of time the roof cavity would cool. Unless your ceiling was insulated this would effect the temp inside. If you had any vents such as in the bathroom, the warm air inside would rise into the ceiling cooling the house. Not appropriate in winter.


Lost me there.

I would think to maintain good temp inside you would you need as much warmth around the house as possible in winter and as much cool air as possible in summer.

Just got it. Your looking at running water through it. I was thinking of air. Could do both Water for the tank and air for the green house.

Heat goes up. If you are worring about cooling the roof area because of the intake of outside air you can run pipes through it so the air volume stays the same. The only real difference would be the temp of the tin on your roof. The vents I ment are the ones that take air from inside your roof eg a whirly bird or roof vent that keep the moisture out. In winter they let the hot air out as well. With the summer idea it would depend on a lot of variables. Cooling your 1000lts fish tank by 10 degrees might mean taking a little of the air under the house. But when the wind blows that happens any way. In this way you at least have an option on where that cooler air goes. If you get the air from burried PVC tubes this would leave you house alone. Heat up the grass instead.

Uncertain John... crossed my mind... but I think the flow rate, plus the thermal circulation should prevent it being an issue...

The current pump is way over-rated... and I'll be trialing a different pump shortly... I'll leave the filter in the smaller pump just in case...

Easier to periodically clean the pump filter than to perform maintainance on the tubes...

Good point though... glad you raised it....

Bearing in mind similar systems are used for normal household hot water systems circulating water through a hot water cylinder....

I suspect it's probably not an issue... who knows what sort of sediments collect/circulate/suspend in a normal hot water cylinder over time...

Rupe
I`ve been in touch with the local solar firm and they reckon the 70mm sealed tube will take 35mm hail as it has thicker glass (2.5mm), the largest hail we get is maybe 10mm..but you never know whats coming these days

F&F,
You`ll need a lot of pipe in the ground to act as a tank cooler.
To cool 1000L by 10C you need to lose about 11.6kw.
100m of 1" pipe in soil that is constantly 10C cooler than the water temp..unlikely as the heat from the water will be warming the soil up around the pipe
Assuming it doesnt..it`ll take a minimum of 26 hours to dump 10C.

Dont know where the 90 mm came into the equation [i run 90mm in shift pist ] 25 mm with water in underground is what i mean

Sorry my fault. We were talking about using air to cool or heat the water and I thought we were still on that. The 90mm or 100mm PCV I was talking about was for cooling air. You have them connected to your green/hot house and when the hot air goes out of the top vent the cool air is sucked in through the ground tubes. I like passive system of heating and cooling. We lined a large shed for a shop and had whirlie birds on the roof that sucked hot air from inside all the walls in summer. So when its 50 degrees outside the air con gets the inside down to 20 in summer.

I'm missing something. Why are copper pipes used for transporting hot water around houses? I can understand the use in heat exchangers etc, but wouldn't copper pipes just do a better job of losing heat in the lines?

Sorry for the stupid question

Easy to use steem, and used to be relatively cheap, corrosion resistant.

If you build a house, surround the pipes with insulation - much less heat loss.

might be off topic, but since you are talking of solar air heating here are some links to a heater made of beer or soda cans that can also be used for cooling:
DIY:
http://inventorspot.com/sodacan_solar_furnace
http://fame.drobicho.com/solarfurnace/SolarFurnace.html

professionally made:
http://www.cansolair.com/

easy and fun to build (especially the preparation)
Of course I am preparing to build one.
it will be BIG!

I suppose you could incorporate an array of PE tubes and heat up water in the same effort

frank

What they use now for house plumping is plastic. I just installed a sink with the plastic tubes. They just push into brass joints or tap back. No draging out the heat gun anymore. And no leaks. Work for both hot and cold water.

You had me at beer.