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Geo NR Gee 07-20-17 10:29 AM

Repurposing a 180 evacuated tube solar hot water system
6 Attachment(s)
About a month ago, I replied to an ad for a large evacuated tube solar hot water system. It was at a brewery that went bankrupt and the new brewery wouldn't be using them and it was needing to be removed. It was originally used for heating the water for the beer they were making. The system originally cost over $70,000 to purchase and install just about 5 years ago they said.

We have spent almost 2 weeks removing everything. Today is the probably the last day and time to remove the tanks.

The system consists of 6 Thermomax HP200 30 tube collectors, Hamilton EVO boiler, 2 insulated 370 gallon insulated storage tanks, pumps, Badger meter units, remote control units and sensors and lots of pipe.

I am not sure what to do with the system. Should we use the system to heat water and store in the hot water tank(s) for floor heating, DHW, forced air heating. I can easily use 3 sections on my property (90 tubes).

Maybe put the heat in the ground during the summer months and pull it back out with a geothermal heat pump during the colder heat demand months? I have two new two ton geo units, pipe and drilling equipment waiting for installation.

Or should I just sell it and buy photovoltaic?

pinballlooking 07-20-17 11:35 PM

Wow cool setup

randen 07-21-17 09:11 AM

Geo NR Gee

Have a look at the Drakes Landing system in Canada. If you can drill holes and have the right soils== have a look


Geo NR Gee 07-23-17 11:12 AM

Thanks Randen, I have been studying the Drake's Landing Solar Community and here is a good .pdf on the project for those who don't know what Randen is referring to.

I must admit, that I am not a good planner and usually just wing it. In my possession are almost all of the supplies and tools to install a system like what is at Drake's Landing although in a much smaller scale. However, I am hesitant to do that here and have stepped back to ask the good folks here for some input.

Like AC Hacker and others have said before, start with the insulation and tighten up the home. We have already upgraded the insulation in the attic last year and have shown improvements on the energy used to heat and cool the house. The windows should be upgraded, but that is not in the budget at the moment. They are vinyl and only 19 years old, and there are better more efficient ones of coarse. The house was built to "Good Cents" energy efficiency standards in 1998, but it surely could have been built better. The exterior walls are mostly 2x4 construction and the insulation under the floors joists was minimal. That will be upgraded this fall after the underfloor heating gets installed and insulated.

We can install the solar evacuated tubes, dig the boreholes, install the tanks and heat pumps, but without a proper sizing of the system or plan, I am worried it may be a huge disaster.

My initial thoughts are to do a manual J analysis on the home. Another door blower test. Drill some boreholes to test for soil conditions. Possibly upgrade the windows and walls with better insulation.

Help.......... please!

Mikesolar 09-04-17 07:57 PM

In case you don't know, EVO has a huge failure rate and for all I know they could be defunct as a company. None of my wholesalers sell them any more. Thermomax is defunct too so getting tubes will be difficult. The old importer is not in business anymore. Ya pays your money and takes yer chances. I wouldn't.

Go PV. It is too cheap not to these days.

Geo NR Gee 09-05-17 12:23 AM

Hmmm. I don't know if you know it or not, but I got all of it for free. Only cost my family members and I some time to disassemble.

I contacted Solarmax in the UK. They were still in business when I spoke to a sales agent in July. The vendor in the US is not in business I was told.

As far as the EVO, I also spoke to them and as far as I know they are also still in business, but I planned on selling the unit anyway. Don't see how it would fit into my simple plans.
Would love to go solar voltaic, but that is not in the budget.

Mikesolar 09-05-17 06:37 AM

The UK company is still in business but people in North America don't seem to know how to use the highly efficient tubes very well and maintain them. The failure rate of tubes especially the Thermomax/Solarmax/Viessmann is quite high when you have a high solar fraction, ie: try to get more 50% of your annual load supplied by them.

The summer temps just get too high and it is hard on seals and other components. This is why I stay with flat panels. For you, it is different as they are free so i would say to go for it but make sure you can extract that heat in the summer for any longevity.

Geo NR Gee 09-05-17 01:05 PM

If I understand you correctly, I need to make sure not to overheat the system and dump the heat or it will ruin the seals and soft parts causing it to prematurely fail?

Mikesolar 09-06-17 08:31 AM

Yes, indeed. These collectors will stagnate at 240C+ if they are sitting in the sun and doing no work. The seals won't last a long time if the system goes for weeks this way.

Geo NR Gee 09-06-17 10:39 AM


Originally Posted by Mikesolar (Post 55445)
Yes, indeed. These collectors will stagnate at 240C+ if they are sitting in the sun and doing no work. The seals won't last a long time if the system goes for weeks this way.

The units that I have are Thermomax HP200. I am not sure, but I read (here ) that they have two different options for a temperature limit.
Unique Feature –
Temperature Limitation Devices
HP200 collectors contain a unique temperature limitation device
for system protection, there are 2 types:
1. Memory spring to limit temperature to 95˚C or 203˚F
Ideal for domestic installations
2. Snap disk to limit temperature to 135˚C or 275˚F.
Ideal for commercial installations
New improved snap disk*
• Over 3.5% more efficient than before
- now up to 81% optical efficiency
• More robust
• More reliable
This collector is referred to as HP250.

HP200 collectors are available in 3 different
sizes – each one with the option of 2 different
temperature limits.
In the table below, where there are 2 figures, HP200 is the first
figure and has a limitation of 95˚C or 203˚F. HP250 is the second figure and
has a limitation of 135˚C or 275˚F. (I have the HP200 units)

Again, my plan was to dump extra heat to the ground storage for the times when we need to heat the house or a preheater for the domestic hot water. So if they are the limiting units like I read, then the only time we should have to worry about stagnation would be in a power outage.

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