Adding antifreeze to system

RoosterBoy

piping arrangements,known or unknow volumes,minor technicalities such as that.

jrc2905

Adding antifreeze to system.

Any suggestions for adding antifreeze to a boiler and reducing the amount lost on the purge?

jrc2905

just in a general application.

Andrew Hagen (ALH)

Transfer Pump

Use a transfer pump to circulate a pre-mixed propylene glycol solution. That way there is no loss. A makeup water connection should not be used on a system containing antifreeze.

-Andrew

Chuck Shaw_4

Dont forget

That a 30% mixture of glycol will result in a BTU output loss of 15% with a 5% increase in head against the system circulator. A 50% mixture of glycol will result in a BTU output loss of 30% and a 50% increase in head against the system circulator.

Also, glycol has a different rate of expansion than water, you may need a larger expansion tank, depending on system size.

Chuck

Andrew Hagen (ALH)

But

head loss is non-linear.

According to Dowfrost data, the specific heat is 7.5% less for 104F Dowfrost propylene glycol at 50% versus 30% solution, and approximately 14% less than water.

-Andrew

Leo

Chuck,
I find this very interesting and have booked marked it. Do you have a reference cause I know I will be argued with.

Thanks,
Leo

Chuck Shaw_4

Yes I do,

The instructions on the anit freeze. I will have to dig them out, and let you know exactly what it says.

Chuck

Chuck Shaw_4

It may

have something to do with the make up of Dow vs. the propolyne glycol that I use.

Chuck