which Solar Glycol strainer??

Paul B_5

Thanks for the feed back But ,I've been doing this solar thing for 17 years. I'm in Canada ,my panels are tilt optimized for Max solar production in spring and fall for some input for low temp radiant applications I'm working. Panel angles at 55 deg year round for my 45 deg N. Latitude, In the summer the additional sunlight hours buys me pretty much 100% solar DHW from March 1 to Oct 15,,And of course on clear cold winter days 100% here as well. Yes I'm oversized on purpose with 60 Vacc tubes, but high angle ,High usage with 8 people in the house really helps clip the overtemp situation for now but in the future I may need a dump load. thanks for the concern , more details to follow if you wish..Paul

Paul B_5

Which is the best strainer for my 50/50 glycol system in solar application and what is a reasonable sized Micron(100 mesh) ??? thanks Paul

ALH_4

Strainer

Why use a strainer in a solar system? Generally these systems should be very clean.

Paul B_5

I'm using a positive displacement Procon Vane pump driven by the sun and I want to guarantee the system stays clean and not jam up the vanes in this expensive pump. Paul

Tony Conner_2

Most...

...positive displacement pumps typically rely on the liquid they're pumping to act as a lubricant for the internals. Unless there's somebody who will regularly check that strainer, and clean if necessary, it can clog, and starve the pump. The best pump guy I know recommends against installing strainers on a lot of applications, because nobody checks them. He gets called to look at FAR more pump failures due to loss of suction liquid than chewed-up by debris in the system.

The strainer "sword" cuts both ways.

Metro Man

clean it up

If you flush system b4 install glycol no reason to install strainer. We have never put a strainer in a closed loop glycol system in 24+ years.

I would think that a strainer would ad significant restriction b4 pump and cause more problems that it is worth. If your really worried about it install some purge valves to purge with an external pump with external strainer. Would leave an easy service access also.

We have done this with older systems. Used to use a charging pump w/canister filter w/strainer to do a quick clean of large particulates. Now we dump, flush, and install new fluid.

ALH_4

Procon

I'm sure the manufacturer would have a recommendation, but from what I can tell, since they are supplied with an integral 100 mesh strainer, I doubt an additional strainer would be necessary in a closed-loop glycol system with no rubber tube. Worst case, there would be a few pieces of copper from reaming the pipe.

Since positive displacement pumps have a nearly vertical pump curve, installing a strainer would have little effect on the flow rate. I would only bother doing this if you are worried about particles that will pass through the internal strainer. I assume a bypass relief will be installed to prevent excessive pressure in the system if someone unwittingly closes a ball valve.

I would flush the pipes when filling, drain that water to waste, then refill with clean glycol solution and rely on the internal strainer. However, Procon may have a different recommendation.

May I ask what the reasons were for choosing this model and type of pump?

hr

It will just add pressure drop

and the suction side is not ideal for any device that could starve the pump.

I like to run some Rhomar cleaner, flush, then add glycol with DI water. There is usually not that much piping in a solar loop to cause dirt issues. Properly installed there may be only 4 solder connections

hot rod

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Paul B_5

Photo : this is a newer style Mag drive Procon driven by 17 watt solar panel witout the internal 100 mesh strainer under that cap on the side of that pump LIKE my old pumps . Not 1 complaint just want to ensure I do not have any problems. Paul

ALH_4

Strainer

Part of the problem with putting the strainer on the discharge side of a positive displacement pump is that once the debris has passed through the pump, some damage has already been done. Since their other pumps have a 100 mesh strainer, that seems like a safe bet. Any strainer you install will have much more surface area than Procon's small internal strainer.

How are you controlling the pump? Is there a differential temperature control?

hr

Does it make much noise?

Looks like a beverage pump I've switch3ed to these clever Laing D-5 solar circs. 1W start up, variable speed 8- 24V DC jobs.

They have a small processor that maximuizes the pv p output. Very efficient and quiet.

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Paul B_5

This pump starts and stops based on the amount of Sunlight and is driven by a 12 volt, 17 watt solar panel (no grid electricity hookup). Pump output is therefore linear and variable dependent on sun/clouds/or just hazey weather..Paul .If you wish i'll send the Pv panel photo as well??

Metro Man

High limit

How do you control high limit? Varible speed pumps based on input voltage are cool but......... what happens in middle of summer, nobody using hot water and this thing keeps crankin'?

I would still rather have diff. control w/HL or aquastat that uses no power as HL

Paul B_5

My pump/motor combination is marketed by Thermodynamics, the pump end is a little louder than I would prefer (depends on the RPM) but the motor is silent.I have a suspicion that all these positive displacement vane unit are sometimes loud. Laing has an excellent product but I never used them Yet!!Paul

Paul B_5

My set up kind of self limits by a high panel andle in the summer and large 120 gallon tank size for now..Paul

Metro Man

Think about it

If you think about how hot all this can get. Sooner or later you will approach pump max temp, tank temp limit, and glycol loop limit,. When you size a solar system (especially closed loop glycol) you need to take into account the most extreme conditions system will ever see. Our busiest service times for closed loop glycol systems is right now. Expansion tanks, PRV, pumps, and etc.. that were ready to fail.... fail now in the 100* weather we are seeing in the Denver area.

A properly design closed loop glycol system should be able to handle all of this.

BTW- if this system is sized large enough to handle any high limit summer time heat temps what does that say for the rest of the year? Are going to be able to provide usable DHW the remaining 3 seasons?

Not knocking what your doing.... just throwing a few "what ifs" because they can turn into "on no's"

Metro Man

great white north

Well there ya go eh! No substitude for experience. Don't think I could get away with that here.

Ever think of drain back water systems? No need to worry about dumping heat.