Document MGJqr5GV8Y6r2BR556xRN4BEL

American Society of Heating and Ventilating Engineers Guide, 1924-25 ing the free area of discharge, even when open wide. In some designs, this results in a serious reduction of capacity. Ice can interfere with their operation. The dampers may be made to close automatically in case of fire, by use of a weight and fusible link arrangement. The dampers should be so located that ice cannot freeze them tight so that adjustment is impossible. Regulation may also be accomplished, just as effectively, by restricting the flow of air into the building (closing the windows or doors), although this is quite inconvenient in many cases. APPLICATION OF VENTILATORS The use of ventilators on factory and mill buildings is too well known to require comment. For pickling rooms, etc., where noxious fumes are produced, they are practically indispensable. Ventilators for houses are becoming quite common, especially for the ventilation of bathrooms, which has been much neglected in the past. A frequent use for ventilators is on the top of chimneys, to prevent down drafts and to increase the updraft by means of wind action. For use on houses, several requirements must be kept iri mind. Good appearance and noiseless operation are very important. The motion of the ventilator, if of the revolving type, must not shake the building or cause knocks or thumps; and the construction must be such that in the winter the movable part does not freeze to the fixed portion of the venti lator and thus stop the rotation. On account of the increasing danger of carbon monoxide posioning, it is becoming regular practice to equip garages with ventilators to carry off the waste gases coming from motor exhausts. Another application of ventilators is found in connection with power ventilating systems on the outlet or discharge opening. A very important application for ventilators is on schools, where re circulation of air is used. The duty required, necessitates careful selection. Down draft must positively be eliminated. Catalog Data Section with INDEX TO MODERN EQUIPMENT (Pages. 446-455) and INDEX TO ADVERTISERS (Pages 456-458) 234