# HFC-227ea (FM-200) system design estimation and design question

Question asked by firesprinklerdesigns on Dec 13, 2017
Latest reply on Jan 5, 2018 by firesprinklerdesigns

I am trying to put together a rough estimate of how much gas it would take for a total flood HFC-227ea (FM-200) system. My total volume of the room is 2,688 ft3. The high temperature of room the tank and discharge piping/nozzles are in is 80 Deg. F. and a low temperature is 70 Deg. F.. The system will be at sea level. It is a room, where according to the MSDS sheets provided to us, has the worst hazard being Diesel Fuel to suppress (engine room). I'm not sure I have the correct "s" in the MDQ Calculation. I think it's (s = 1.885 + (0.0046 x 70F.) = 2.207). But I'm not sure. "The Design Concentration (% by Volume)" in the "Table A.5.5.1(i) HFC-227ea Total Flooding Quantity (U.S. Units)" table is confusing me. I know those numbers are important but for the life of me I can't remember why (i.e. 6, 6.25, 7, 8, 9 and so on).

The manufacture I've used in the past has a Class B Suppression Design Concentration Table in their Design Manual (Using a Cup Burner test provided by Great Lakes Chemical Corporation). For "Diesel" on their table the Cup Burner valve (% v/v) was 6.7%. Adding 30% to the design concentration (for safety factor) gives me a % v/v of 8.7. So I would assume:

W = (2,688 ft3 / 2.207) x (8.7% / 100% - 8.7%) = 116.06 Lbs

My question is am I correct by using 2.207 as my "s" in my calculation or do I need to modify it because of the "The Design Concentration (% by Volume)" in the "Table A.5.5.1(i) HFC-227ea Total Flooding Quantity (U.S. Units)" table?

This is just for a rough estimate to bid the project. I would like to thank anyone ahead of time that might be able to help me on this subject.