Air Conditioning Research.

Air conditioning of passenger carriages is being steadily developed in Europe. On the London Underground Railways special research is now being undertaken with the object of bettering air conditioning arrangements and reducing travel noise. For the purpose of the experiment, a typical passenger carriage has been taken, and all ventilators and windows sealed up. Air conditioning apparatus by Frigidaire Ltd., has been introduced, most of the plant being bolted to the under-frame.

Air is drawn from inside the car, to pass over the cooling coils of a refrigerator system located beneath the floor. This refrigerator consists of a compressor, condenser, and air-cooling coils, the compressor being driven by belt from a 3-h.p. motor. Leaving the refrigerator, the clean air passes up into a space between the outer shell of the car roof and the ceiling, from whence it is distributed into the interior. Unlike some systems of air-conditioning, where ammonia or similar media are employed, in the new London Underground plan the refrigerating fluid favoured is known as “Freon.”