SRAM,
I dont know which country you are in.
Generally, the cable industry has been developing halogen free, low smoke cables for a number of years.
The development of such cable was brought about because of fires doing serious damage. The conventional insulation and sheath material for internal cables was PVC. Unfortunately, this material releases copious amounts of chlorine. With water from fire extinguishers etc., the chlorine combines with the water to produce hydrochloric acid. If the building is a concrete/steel design, the long term damage is serious.
You say the fire started in the AC system. Usually this sort of gear is made with cheap cable and wire and is almost guaranteed to be PVC. My approach would be to exercise caution in your assessment, because the cooling fans etc will almost certainly distribute the soot and chlorine byproducts right through the computer gear. failure in the long term is almost guaranteed.
Many companies and organisations are specifying alternative cable constructions. Generally these are based on halogen (chlorine/bromine) polymer blends and/or include aluminium salts. The type of material chosen depends on whether you are dealing with LV or HV power cable or whether you are dealing with ELV control cable or maybe telecommunications/data cable.
The USA, Europe, Australia are switched on to these new designs.
hope this helps.