Anti-freeze/glycol %

bruce garner

bruce garner

bruce garner

adding glycol

I've added a small area in my workshop that I installed radiant tube in . I installed 1 half inch stadler veiga (apox. 250'). I put down 2 inches of insulation and attached the tube to reinforcing mesh atop of it. My question is, how do I get the right % of glycol in it? Do I calculate tube size x lenght (figure 30%) mix it together in a bucket and add two purge stations at either side and push it through with a pump? I have a brazed plate heat exchanger (I haven't installed it jet) to separate the two system but was wondering if any one can offer a schetch and or a site (possibly drawing). Also do I install an expansion tank and if so what kind? Make up supply (what if it leaks. I don't want to add freash water to it and at what pressure should it be at.

thanks,

bg

Brad White_9

Glycol Pre-Mix

Typically the glycol is pre-mixed, purchased as such or mixed on-site. For small batches, I would use pre-mixed if available. It is done by weight not volume depending on the rating standard. Not as much difference but still good to know. Drew Longnecker at Noble is a good resource. Noble No-Burst is a product we have specified.

For filling and looking for leaks, I would use a sensitive pressure gauge with as low a range as I could find. If your budget can afford it, an Axiom unit is nice (axiomind.com). Consists of a translucent tank, peristoltic pump and alarm outputs. Their base unit maintains 18 psig which should be plenty. If there is a depletion in fluid that tells you there is a leak.

If you go the manual fill route, Silver King Mfg. has a nice brass hose-end pump which runs about $140 and can be used for other things like annoying the cat. Great way to add chemicals into a closed system. Blackmer also makes rotary pumps, often used for drum dispensing. I own a Silver King force pump. My cat hates it.

As for expansion tanks, any confined water system requires one. For the size system you are describing, the smallest available are likely large enough. Just make sure that the diaphragm is glycol compatible. Most are.

hr

Treat the \"b\" side

of that heat exchanger like a boiler. It will need an air purger, expansion tank, prv, possibly a low water cutoff depending on your code.I'd not worry about a fill system on that small of a job.

A ball valve with a boiler drain on both sides is a quick simple fill purge point.

Webstone makes an excellent one piece valve for this. Called their P/S valve.

I'd buy a 5 gallon bucket of premix and pump till it is full. Rhomar, Hubbard Hall, maybe Nobel? are a couple that sell premix in 5 gallon quantities. Rhomar may even sell one gallon bottles if you ask. Typical, from Rhomar is a 40% mix with DI water used to blend.

Be sure to clean the system with a TSP or hydronic cleaner before putting the juice to 'er.

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Tombig_5

Glycol Systems

Like hr said, you have to treat the glycol side as it's own separate closed system. Just picture the HX as another boiler with its related add-ons. Expansion tank and pressure relief are crucial!

I've filled from a five gallon bucket with a gasketed hose bib drilled into the side near the bottom. A small pressure boosting pump will get you up to the needed psi. This was a 3000sf snow melt w/no HX. The larger exp tank was filled to 60psi to add to the system thru the reducing valve if needed

hr

This here pump

is inexpensive and handy to have around the house. This is a Little Giant brand. plenty of others at the home centers. they even come with the garden hose adapter.

Drop it into the bucket of glycol with a wash machine hose connected. A second washer hose will be the purge hose that also goes into the bucket. Pump awy until all the air bubbles clear out. close the purge valve and pressurize to 12 psi or expansion tank pre-charge pressure.

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