Is there any guidance on how much of a safety factor an anti-freeze solution should have? I cannot find any such in 13, but of course 13 requires an 8 degree F cushion for wet systems (maintain at or above 40 F). Looking at the ASHRAE Handbook there is weather data which shows the mean coldest temp and a standard deviation for locations throughout the USA and Canada. Using that data, what should be the design basis, i.e. how many standard deviations below the mean coldest temp? Does it make sense for a locale with a reported mean coldest temp of -10 and 5.8 standard deviation to design for 2 standard deviations below and a safety factor? So, freeze point of anti-freeze solution = -10 - 2(5.8) -8 = -30 F or lower? How accurate are the pocket refractometers used in the field? Do most contractors use pre-mixed anti-freeze solutions? As always, the Forum's insights are welcome.
Dave David A. de Vries, P.E., CSP Firetech Engineering Incorporated _______________________________________________ Sprinklerforum mailing list [email protected] http://fireball.firesprinkler.org/mailman/listinfo/sprinklerforum For Technical Assistance, send an email to: [email protected] To Unsubscribe, send an email to:[email protected] (Put the word unsubscribe in the subject field)
