Copyright Goodheart-Willcox Co., Inc. May not be reproduced or posted to a publicly accessible website. Chapter 5 Measurement 977 Chapter 9 Name __________________________________ Date _____________ Class _____________ Exercise 5-4 In some areas of the country, it is commo to fi ll hydronic systems with a mixture of ethylene or propylene glycol to prevent the pipes from freezing when exposed to cold temperatures. Use the Hydronic System Mixtures chart to answer the following questions. Hydronic System Mixtures Temperature Ethylene Glycol (%) Propylene Glycol (%) Freeze Burst Freeze Burst 20°F (–6.6°C) 17 12 18 12 10°F (–12.2°C) 26 18 29 20 0°F (–17.8°C) 35 23 36 24 –10°F (–23.3°C) 41 27 42 28 –20°F (–28.9°C) 46 30 46 31 –30°F (–34.4°C) 50 31 50 33 –40°F (–40°C) 54 35 31 55 –50°F (–45.5°C) 59 31 57 35 –60°F (–51°C) 63 31 60 35 Goodheart-Willcox Publisher 1. If the building owner wants the system protected to a g p freeze point (the temperature at which ice crystals begin to form) of 0°F, how much ethylene glycol would be required to mix with the water? Roun your answer to the next highest gallon. __________ gallons 2. If propylene glycol was used to a freeze point of –30°F, how much glycol would be mixed with the water? Round your answer to the next highest gallon. __________ gallons 3. If propylene glycol was used to a b i burst point ( h hi h h fl (the temperature at which uid solidifies enough to cause piping damage) of –40°F, fi how much glycol would be necessary? Round your answer to the next highest gallon. __________ gallons