Tent mod kit lets air flow.

The convective space heater, NSN 4520-01-431-8927, efficiently heats your modular command post shelter (MCPS) as long as there's a free flow of air. The heater draws cold air from the shelter through the air supply duct. The air's forced through the heat exchanger, where it's heated. The warm air then passes through the air return duct and into the shelter.

There's only one problem: The earliest versions of the MCPS were fielded without air duct openings. Without them, you have to insert both the supply and return ducts under the shelter wall. The weight of the wall squeezes the ducts and cuts down the airflow. Less air causes the heater to overheat or to constantly cycle on and off. As a result, carbon builds up in the burner. In the end, you have to clean the burner more often.

Avoid overheating, cycling, carbon buildup and extra cleaning. If your MCPS doesn't have air duct openings, install the tent wall modification kit, NSN 4520-01-493-3215. The kit allows you to cut openings in the shelter wall and to add a sleeve to seal around the ducts. Attaching the supply and return ducts to the openings lets air flow freely through the space heater.

You can still use your space heater while you're waiting for the kit to arrive. Just make sure you prop up the shelter wall so it doesn't squeeze the supply and return ducts and restrict airflow.