The Building 440 is an insulated, refrigerated hangar. There is an office and instrumentation building, a cold-weather engine test cell, the refrigeration system, mechanical-draft cooling towers, and a steam-heating plant. The main chamber is wide, deep, and tall at the center of the hangar. It was constructed to hold aircraft as large as a B-29, its size also fitting the larger Convair B-36 Peacemaker. In 1968, a by extension was added. It now has working area. This allows it to test aircraft as large as a C-5A. Under hot conditions, it can achieve. The All-Weather Room is by. It has a temperature range from to. Rainfall can be as high as per hour and the wind can be as high as. Snow can be made in the chamber. The Temperature-Altitude Chamber is by with a height of. Altitudes up to can be simulated. The temperature range is to. The engine test cell was originally used for aircraft engines. It was about by with a height of. It is now called the Equipment Test Chamber and is used mainly for tanks, trucks, and other equipment. The original building had small tests rooms for desert, hot, marine, and jungle conditions. These have been eliminated. The original floor of the building was constructed of reinforced-concrete slabs that were thick and square. The slabs rested on of cellular glass blocks over reinforced concrete. In 1990, much of this floor was replaced with square slabs. The walls and door are insulated with of glass-wool board sheathed in galvanized steel. To seal the doors, they are pulled against foam rubber seals. The ceiling insulation is on a corrugated steel deck, which is suspended from the roof trusses by chains.
Refrigeration system
The original coolant was R-12 refrigerant. Liquid refrigerant is held in a low-pressure surge tank. The pressure in this tank is maintained at the saturation pressure for the desired temperature for the cooling coils. Vapor from this tank is compressed to a gage pressure of by the first-stage compressor. The compressed vapor is expanded into an intermediate, desuperheater tank. Liquid condensed in this expansion is drained back to the surge tank. The remaining vapor is compressed in a high-stage compressor to a gage pressure of about. Heat is transferred from the hot vapor to cooling water. Any condensed liquid is returned to the intermediate tank, the surge tank, or the supply tank. Liquid refrigerant from the surge tank is pumped through the cooling coils at sufficient pressure to avoid vaporization. Warmed liquid is returned to the surge tank. As its pressure is reduced, a portion of this liquid will flash into vapor. There are three such refrigeration systems. Each low-stage compressor is powered by a motor and each high-stage compressor is powered by a motor. The system was built by York Corporation. The original motors were Allis-Chalmersinduction motors. They have been replaced by variable frequency, synchronous motors manufactured by EMICC that operate between 350 and 1800 rpm. Recent efforts have been made to change from ozone-depleting refrigerants. For engine tests, there is need for makeup air. The system originally could cool per second of humid air. In 1966, this was increased to per second. Air is also cooled by a two-stage heat exchanger. The first stage uses of 20% calcium chloride brine pre-cooled to. The second stage uses of methylene chloride pre-cooled to. This can cool per second of humid air from to for 40 minutes.
