ANSI/ASHRAE Standard 15-1994, Safety Code For Mechanical Refrigeration

Request from: William S. Apple, Philip Morris U.S.A., P.O. Box 26603, Richmond, VA 23261-6603.

Reference: This request refers to ANSI/ASHRAE Standard 15-1994, subclause 8.13.6.

Background: Mr. Apple’s letter states:

"No open flames that use combustion air from the machinery room shall be installed where any refrigerant is used?.Combustion equipment shall not be installed in the same machinery room with refrigerant-containing equipment except under one of the following conditions:

(a) combustion air is ducted from outside the machinery room and sealed in such a manner as to prevent any refrigerant from entering the combustion, or

(b) a refrigerant vapor detector is employed to automatically shut down the combustion process in the event of refrigerant leakage."

Philip Morris Interpretation: Mr. Apple’s letter opines that the "event of refrigerant leakage" is confirmed by a refrigerant leak detector alarming at the TLV-TWA of the refrigerant in use. An alarm at any level below the TLV-TWA of the refrigerant in use does not meet the criteria of "refrigerant leakage" and no automatic shutdown is required at an alarm level below the TLV-TWA of the refrigerant in use in order to comply with the standard.

Question: Is Philip Morris’ Interpretation correct?

Answer: Yes.

Comment: A refrigerant monitor alarm indicates a detectable concentration of the refrigerant being monitored and the cause of the alarm should be investigated. Automatic shutdown of equipment at refrigerant concentrations below the TLV-TWA are not required to comply with 8.13.6.