glycol fill system

Dorsey Davis_2

Hey all you wet heads! I've installed a solar thermal system and have charged it with water and purged it. Now I need to empty it, measure it and then refill with a glycol-water mix. I'd like a slick way to refill the loop. I'm willing to spend a bit if it's a system or tool I can use regularly. My concern is getting the mix in and then bleeding the air out without wasting much fluid. The glycol I'm using, Dow HD is frigging expensive.

Derheatmeister

Cleaning

What kinda system?

Solar direct?...Tanks?

Are you cleaning the system first?

Glycol pump is the way to install the fluid i.e Liberty 331 or Grainger has an pump as well..

Nick_35

Glycol Express?
www.tekforceproducts.com

Mike C._4

solar glycol fill

I just went through the same thing filling my solar loop with no pump handy that would get to about the 42 psi I wanted. A drill pump will get you to about 18 psi. A little electric transfer pump only got me to about the same. A cheap RV hand gylcol pump actually got me to 30 psi before the handle broke. And now for the big one-I filled a long garden hose with glycol using the drill pump until it had no air. Hooked it up to the solar loop. Removed the drill pump, made an adapter to hook my air compressor up to the hose to force the glycol into the solar loop to 44 psi. Repeated a couple of times so not to blow air through the hose. Bled the air out the vent at the solar panels and at the spirotherm micro bubble vent. Been checking for air for the last two weeks and have no problems. It was easy.

Mike

hot_rod

how much? how quickly? 4 options

Here are some of the options. A small submersible sump pump moves pretty good flow but peaks out about 12psi. Cheap, multi purposed, limited fill pressure. 60 bucks or so.

A small hand pump like shown will actually pump up to about 80ps1! Very slow going, seems like a couple tablespoons per stroke They actually have a male thread to screw right into many of the Euro solar pump stations. 80 bucks or so.

The drill motor pump, a good quality one,like this Zuwa will pump in excess of 60 psi, fairly quickly, and is a positive displacement pump, the self priming feature is handy. $150 ish Great for pumping out toilets with a cordless drill attached

A 1/2 hp transfer pump, available as Teel, Liberty, Dayton and other names. 30- 45 psi range depending on head, very fast flow, not self primimg. I've used this one with a variaty of washer hoses and euro thread hoses for about 20 years now. it fits inside a 5 gallon plastic bucket with the hoses. I added a gauge and quick turn ball valve to prevent over-filling. Cast iron or aluminum versions $125 and up. A lifetime tool if you care for it.

Use a compressor to blow out all of the air, drain any low points, pre-mix the glycol and pump it through until all air bubbles disapear it sometimes takes a few minutes to blast all the air out, depending on how much pump power you have. that 1/2 hp will blow most systems air free in a minute or two.

Expect to pay $800 or more for a top of the line glycol purge cart like the on shown in #49.

hr

Dorsey Davis_2

cleaning

Its indirect, closed loop. The solar tank is a Superstor with a copper/nickel heat coil. What do you suggest to clean/purge it? I looked up the Liberty 331 pump. Looks like the one. I've installed microbubble scrubbers on radiant systems but not on solar loops. Should I be installing them on solar?

hot_rod

Ideally clean it

with a good hydronic cleaner product. Is it a soldered copper pipe system? If so getting flux residue out is very important as it can compromise your glycol inhibitor package.

Some installers use a TSP mixture, a strong soap really. I've used automatic dishwasher detergent from time to time. It's critical that you get a good flush after using cleaners. You don't want soap and glycol blending any more than flux and glycol.

The cleaner the better for years of trouble free service. Glycol in a solar system can see some extreme conditions, in excess of 325F temperatures under stagnation conditions. Use top brand HD (heavy duty) glycols in a clean, clean system.

Check the fluid quality yearly, this will tell you how often the system is being stagnated and stressing the fluid. Use a heat dump,aka load sheding to prevent over heating the fluid, if needed.

hr

Kirk_4

Solar Glycol feeder

See the attached link (www.axiomind.com). Axiom's solar line of feeders will supply a system with fill pressures up to 35psi.

Ron Huber_2

das is good, Ya!

This is without a doubt the best glycol/solar charger that I have ever used/owned. It is a German product sold by Heliodyne, you can buy them direct from Germany but I think you will pay about the same. High head pump, high temp hoses, stainless steel hose bibs, nice little cart to wheel it around . Did a 14 panel system, 16 two panel systems,and six evac. tube systems, and this gets the air out pronto and no mess, I only use it for the Tyfocor that we use (40/60 glycol and distilled water). If you are going to need a charging pump for other applications, just buy a high head pump like the ones Zoeller sells, can even be found at good hardware stores.

Royboy

i've been using ...

almost the same setup with the 1/2 hp transfer pump for filling/purging solar and other hydronic systems for quite a few years. on my second pump. and I like your pump piping better than mine, hr - thanks.

my best upgrade was when I strapped the hoses onto a chunk of wood that the bucket handle holds steady in the bucket. rather not think how many times I (or surroundings) got sprayed before that occurred to me ;-)

Roy

Sunrise Energy Services

Royboy

this reminds me

of other questions I have about filling solar/hydronic systems.

to date I haven't done much active cleaning of piping - have usually just changed water a time or two. but it seems like a good idea to use something more cleansing!

the other thing I've not done to date is use distilled or otherwise purified water in filling systems. be curious as to other folks practices on that. my local water is seems good - relatively neutral, few minerals.

I've just begun putting antifreeze into a project of 24 drainback solar water heaters. the systems have been running for up to a couple months on water and I'm draining that out, flushing with hot line water, and filling with antifreeze. WI state rebates require antifreeze in drainbacks - a questionable requirement in my mind, but these are some of are the first drainbacks I'm doing, so I'm still on the steep part of the learning curve?

it's a little off-topic but I do find the filling of drainbacks to be rather delightful in contrast to filling/purging pressurized glycol systems. you're just pouring/pumping it in, letting air out & pressure equalize and you're good to go. not a reason in itself to do a drainback, but a nice side-benefit.

Roy

Sunrise Energy Services

hot_rod

I heard WI was backing off

on the, very odd, glycol in drainback systems requirement. Maybe the effects of parched glycol are starting to show up?

Stressing that glycol may cause the ph to drop and then problems will start to show up all over, like pinholes!

If you have used flux and pipe dope I feel the system needs to be run with a good cleaner. Plain tap water doesn't touch oils and some of the waxy fluxes.

Rhomar would be my choice, but plenty of installers swear by good old TSP, mainly on steam systems which must end up with some threading oil, at least.

DI or DM water only if the available water is really hard or weird ph. Certainly not a bad practice to haul filtered water if you have a barrel and means to move it around.

One contractor I know rents the DI filters and just runs the jobsite water through them and then returns it to Culligan after so many gallons of use. I suppose if you do commercial or a lot of fills that would make sense.

hr

hot_rod

alligator clamps!

A contractor shared that tip with me recently, in Wisconsin in fact. He clips the hoses to the side of the bucket, with large spring clamps, to keep them in line.

hr