Wet heads & boiler folk...question

[Snoring Beagle]

Ok I bought a refractometer to verify proper amounts of anti freeze in residential systems.

I have been doing this in commercial for awhile in chiller and boiler loops.

I have recently tried to buy some 100% strength from local suppliers within 100 miles, ( I am in northern Michigan) and none bothered to stock it or can get it special order with a nice add on charge. Then the counter people would look as if why?

They all have the -100* stuff which is a 70% blend of PG and water basically.

Considering the convoluted ways these residential systems can be installed with lack of vents and the number of zones sometimes it is not so straight forward to drain and replace. The math with 70% gets crazy and it becomes a hit or miss preposition to get the right ratio without a refractometer.

My question is what is so popular with the 70% solutions.

When 100% is easier to mix and add. Then if done right you could use the refractometer and a known amount of 100% added to a clean system and based on dilution get a good estimate of total volume.

Any Ideas??

[flange]

Most techs dont know what they are buying, and wont even notice the difference until they test the concentration. It allows them to be competive in the marketplace if you dont notice. I buy glycol right from a chemical distribution wholesaler in the city. You can get it with or without inhibitors and 100 % concentration.

[Snoring Beagle]

I found that if I am willing to travel a couple hundred miles or so round trip I can buy the undiluted version at the No Burst plant on the west shore of the state. The Dow plant is closer but the Dow brand is a lot more expensive and doesn't make sense on Domestic stuff.

[hvaclover]

Dang.

Maybe you should stick to warm air systems:D

[skippedover]

Go to a recreational vehicle center and buy their anti-freeze. You gotta be careful in residential boilers as too heavy a conentration can make strange things happen. The requirement is for food grade anti-freeze and since the water lines in campers and mobile homes and the like are for potable water, they always have the right stuff. The maximum concentration should never exceed 50%, unless you like callbacks.

If you add 4-gallons of pure water to 10-gallons of 70% solution, you'll have a 50% mix. On a per gallon basis, that's about 51.2 ounces or approximatelyl 6-1/2 8-oz. cups of fresh water to a gallon of 70% mix. If you want to do a low mass boiler, I wouldn't exceed 35% solution. From 70%, that's a gallon of fresh water to a gallon of 70% and you've got your 35%. I think that's why the 70% is so common, the manufacturer's of hydro-air coils and low mass boilers all like the 35% mix as a maximum. Heat transfer becomes too much of an issue above that. Mind you, 35% is not freeze protection, it's just burst protection. If someone ignores their system and it freezes, it still needs to be thawed before the solution can be pumped through the system again.

[Snoring Beagle]

skippedover, flange, you guys know your stuff.



Clover, how about a size 12 up sideways in your warm air exhaust vent buddy. :D

Hey How ya doing you been quite lately?

[hvaclover]

skippedover, flange, you guys know your stuff.



Clover, how about a size 12 up sideways in your warm air exhaust vent buddy. :D

Hey How ya doing you been quite lately?

Naw. Been making trouble at a DIY site. Some DIYer was going to send an HO here to get install advice.

I sicked Hey-Bob on him.:D