Specifications and characteristics of a soundproofed, electrically shielded and thermally insulated room

Abstract

The specification for the construction of a moderately priced, sound proofed, electrically shielded and thermally insulated (Spesti) room, with a 12 volt DC “house system,” is given. Data are presented on the physical characteristics of the room; for example, (a) dry bulb temperature can be altered in the range 32.4°C to 17.5°C, and for the circulation of temperate conditioned air a high degree of consistency is obtained of temperature and humidity; (b) ambient sound level inside the room, with the air conditioning unit functioning at quiet intake, is 35 db. (A). Average sound attenuation in the range 6 kc.p.s. to 300 c.p.s. is 44 db. (Lin) for pressure level and 44.3 db. (Weighted) for sound level; (c) the room is isolated from external impacts to the extent of 20 db.; and (d) suppression of 50 c.p.s. electrical interference and attenuation of 44 kc.p.s. radio signals are of the order of 200/1 or 46 db.