Fuel Characteristic Constant of Trichloronsilane (TCS) for Venting EQ?

[designsimple]

I use 0.14 as the fuel characteristic constant in the venting equation of NFPA 68 to calculate the explosion relief area for trichloronsilane (TCS, flammable gas). Is it proper? Should I use 0.17 (maximum) for it? I'm design a HPM room and have a very limited exterior surface area I can use for the relief area. I already have a touch situation now to get enough opening area to meet the relief area even if I use 0.14 for the fuel characteristic constant. But I have a cloud in my mind whether 0.14 or 0.17 should be used for the constant to calculate the relief area. I greatly appreciate that someone may can answer this.

Thanks,