Evacuated tube solar thermal collectors feeding a thermosiphon

Quick overview of a two-in-series evacuated tube solar thermal collector set feeding a 55-gallon plastic drum via thermosiphon with no moving parts. In this instance I prefer the British spelling of "thermosyphon" but decided to stay with the American spelling for authenticity. Also, "Herbs" should be pronounced "Herbs" and not "Erbs" because there's a fucking "H" in it. Thank you, Eddie Izzard.

[@moaski]

Could you run an evacuated heat tube thermosiphon system with in-floor radiant heat within the slab of a workshop?

[@NoelBarlau]

Sure, but the evacuated tube solar is designed to heat a small amount of water to a high temperature, whereas a flat panel system would be better suited to heating a large thermal mass to a lower temperature.

[@moaski]

@@NoelBarlau thanks for the reply. "Flat panel"... Are you referring to PV?

[@NoelBarlau]

@@moaski No, I was referring to a flat panel solar thermal collector. They're much more efficient at heating more mass to lower Delta T's. Although PV solar has actually overtaken solar thermal on a cost per watt basis in the past couple of years. Look into Electrodacus hardware for PV heating using resistive elements embedded in a slab.

[@Rustinox]

Interesting way to heat up the workshop.

[@NoelBarlau]

Thanks. I'm always messing around with little experiments like this. It's as much for the enjoyment of setting up the project itself as it is for the actual end result of "free" heat from things I already had lying around gathering dust. We've had the collectors for over a decade now and I hadn't gotten around to doing anything with them. Shameful, really.

[@davidor2715]

Where did you bought those systems?

[@NoelBarlau]

We imported them directly from China as test units. At the time we were going to import and re-sell them, but as it turns out we weren't really sales people so we gave up on the idea. Now that PV solar is so much cheaper, it's economically more efficient to heat water directly with PV. Look into Electrodacus solar controllers with diversion heating.

[@lookcreations]

So what’s the plan for the hot water in the barrel?

[@NoelBarlau]

Just let it radiate heat into the shop over the cool winter months. During the warmer months I'll just drain the tank and cover the collectors. I always have big plans to integrate them into the house, using them to preheat the feed for the hybrid water heater. But somehow I never get around to it. We're about to embark on a complete renovation of the house, so it may happen eventually.

[@lookcreations]

Noel Barlau I’ve long thought about similar with a heat échange radiator inside my workshop. Ideal would be an underfloor pipe matrix heating the shop slab. Bit late to start chopping the slab though. 👍😎

[@NoelBarlau]

@@lookcreations Same. If I could go back in time to just before the concrete pour I'd have ran both Pex loops and some long wire loops so I could use the Electrodacus DMPPT450. Realistically, I really only need supplemental heat about 4 months out of the year here in Atlanta.