What type of antifreeze is typically used in a closed loop system and why is it needed? Also, what level of protection (degrees) should the system be designed for? Thanks for the help
Hi and welcome! There are two major types of antifreeze used. Glycol based and methanol based. There is also a non toxic glycol used under the brand name environol. antifreeze is used in the loop to protect it and your equipment from freezing if the loop temp dips below 32 degrees after leaving the unit. The amount of antifreeze needed to operate any given loop field is a function of the winter time design temps for the system. 20% is a general catch all, but not to be relied on without more info. Hope this helps Eric
Environol is a ethanol based antifreeze. Here is info on selection and use from Waterfurnace. Excerpted page 19 from- http://secure.waterfurnace.com/docs/FB507406666/InstMan/IM1542EW.pdf Most current Geo HPs are designed to operate in heating with entering source temperatures as low as 20F. Your antifreeze protection level should at least meet the control board setting for freeze protection safety lockout. In most cases your choice is 30F for water or 20F for antifreeze.
Thanks for the info! Anyone happen to know where you can buy methanol (generally)? I don't know the first clue how to get my hands on this stuff.
To add to this a bit, keep in mind that if you have a 20 F EWT, you usually have 15F leaving WATER temperature. For the water to be 15F the medium cooling it down has to be less than that, you need a delta T to transfer heat). Thus the inside of the coax is SIGNIFICANTLY colder than 15F, which is why that part always builds up ice first.
Google search for Methanol Fuel near me. Look for race tracks, etc. There are products out there that are 50% to 99+T% methanol. https://www.amazon.com/Snow-Perform...=UTF8&qid=1508993699&sr=8-3&keywords=methanol https://vpracingfuels.com/product/m1/
We send local diy ers to a speed shop for go carts, where they can purchase in 1 gallon increments for around 4.00 a gallon. Eric