Diesel Engines Need to Breath

Diesel engines need to breath just like the rest of us. At first glance, this fire pump room looks like a very clean, well designed layout. But if you take another look, you will notice that there is no ventilation. NFPA requires that a fan and louver be installed, wired to open when the pump is running in a fire pump room when a diesel engine is used. This accomplishes two things: 1) keeping the room below 120f 2) providing enough oxygen for combustion.

I showed up on-site and performed all the usual set up steps like filling the batteries with electrolytes, lining up the coupling, checking the fuel in the tank, bleeding the air out of the fuel lines, making sure the jockey pump was spinning the right way, swapping the suction and discharge gauges for my certified gauges, connecting the batteries. I go to start the engine for the first time, and it fell right on its face. It ran for 10 seconds and then died in a pathetic gurgle. It was starved for air.

In order to run the fire pump test, the larger door to the pump had to be open. This means that if that door is closed, the fire pump is essentially incapable of running and the building is without fire protection. I pointed this small detail out to our customer, the fire sprinkler contractor, and they were able to talk with the owner and solve the problem by installing a fan and louver in the fire pump room.