Document gOX4DxxXpzYr46z5pLxj65KN

232 CHAPTER 11 . 1950 Guide tremely cold weather, and where no provision is made for humidification, the relative humidity may be 20 per cent or less. , Consequently, in using the figures listed in Table 2, consideration should be given to the actual relative humidity to be maintained, if provision is to be made for humidifi cation. If no humidification is to be provided, the higher temperatures may not even produce comfort on cold days; if humidity is to be main-: tained at 50 per cent, the lower temperatures will apply. Heating Load 233 In rooms having large glass areas, when sun is not shining, or in rooms: with walls having a high transmission coefficient, the lowered surface tern- perature will cause a feeling of coolness even though the air temperature in the room is at or above the temperatures indicated in the table. In rooms*' of this character, it is desirable to design for even higher temperatures than those listed, unless a compensating high temperature surface is installed to offset the low temperature surfaces. The inside temperatures specified in Table 2 will not necessarily apply to . panel heated rooms due to the fact that the panels usually maintain a higher wall or glass surface temperature, thus producing comfort at lower air temperatures. Temperature at Proper Level. In making the actual heat loss compu- ` tations, however, for the various rooms in a building it is often necessary Table 2. Winter Inside Dry-Bulb Temperatures Usually Specified* Type of Building Dec F Type of Building Dec F Schools-- Class rooms.---------------------- .... Assembly rooms_~ --- Gymnasiums.-------------------,-- Toilets and baths.----------- i___ Wardrobe and locker rooms.... Kitchens........... --.-------------- - Dining and lunch rooms Playrooms.............. Natatoriums_________________ 70-72 68-72 55-65 70 65-68 66 65-70 60-65 75 Hospitals-- Private rooms... Private rooms (surgical) Operating rooms.` Wards. Kitchens and laundries Toilets Bathrooms...... ...................._ 70-72 70-80 70-95 68 66 68 70-80 Theaters-- Seating space. __ . Lounge rooms...... ........ Toilets._____ ____ __ ____ 68-72 68-72 68 Hotels-- Bedrooms and baths._..__ . Dining rooms........... Kitchens and laundries Ballrooms.... ___ __ Toilets and service rooms........ 70 70 66 65-68 68 Homes............. Stores ............................. Public buildings._____________ Warm air baths.. Steam baths_______________ ___ Factories and machine shops.. Foundries and boiler shops__ Paint shops.___________________ 70-72 65-68 68-72 120 no 60-65 50-60 80 * The most comfortable dry-bulb temperature to be maintained depend! on the relative humidity and air motion. These three factors considered together constitute what is termed the effective temperature: (See Chapter 6.) When relative humidity is not controlled separately, optimum dry-bulb temperature for comfort will be slightly higher than shown in Table 2. to modify the temperatures given in Table 2 so that the air temperature at the proper level will be used. By air temperature at the proper level is' meant, in the case of walls, the air temperature at the mean height be tween floor and ceiling; in the case of glass, the air temperature at the mean height of the glass; in the case of roof or ceiling,-the air temperature at the mean height of the roof or ceiling above the floor of the heated, room; and in the case of floors, the air temperature at the floor level. Temperature at Ceiling. The air temperature at the ceiling is generally higher than at the breathing level due to stratification of air resulting from the tendency of the warmer or less dense air to rise. An allowance for this fact should be made in calculating ceiling heat losses, particularly in the case of high ceilings. However, the exact allowance to be made may be somewhat difficult to determine as it depends on many factors, including. (1) the type of heating system, (2) ceiling height, and (3) the insideoutside temperature differential. The type of heating system' is par-