Document mbXj7032KdnZ17x6eMjX1390

404 CHAPTER 22 1946 Guide Mechanical Warm Air Systems 405 GROUP 5. Branch Ang/es and E/botvs (not including boots) 5 Fq.Fi IO Fq.Ft. 30 Eg.Ft. 5 EqFt. JO Eg Ft. . AOFq.Ft lOEg.Ft. GROUP 6>. Boot from Branch to Stack. obtained by the use of an air washer where the temperature of the city or well, water is sufficiently low (55 F or lower), and where a sufficient volume of water can be provided. Unless the temperature of the leaving water is below the dew-point temperature of the indoor air at the time the washer is started, both the relative and absolute humidities will be somewhat increased. Coils of copper finned tubing through which cold water is pumped are available for cooling. They require less space than air washers and have the advantage that no moisture is added to the air when the temperature of the water rises above the dew-point. Ample coil surface and fan capacity are necessary with'this type of cooling. It is thoroughly feasible to use ice or mechanical- refrigeration in con nection with a warm air system and to cool the building by this method; Duct Wow joist- 30 (Includes Return Intake) 50 (Includes Return Intake) Group 7 Registers (/nc/uding tosses in stackhead and velocity pressure) TA31E 7. Equivalent Length for Registers. Deflexcrtiioorn? t Angle- (See diagrams at right) Deflec Baseboard High Sidewall Register tion or Low For throw of air of- 7.Ang/e Sidewall less than Register /3 feet over 13 feet O'. 35 Eg. Ft. 35Eg. Ft. 70 Eg. Ft. 15' 40 - - 40 - - 80 - ZZ' 45 -A 45 g0 - 30' 60 - - 60 - - 5II 45'. f/5 - U5 - - 230- ' Notes for Table 7. a) When turning vanes are used <n stackhead use 0.7 of values tn columns 2 to 4. b) Values shown in 2nd and 3rd columns in Table are for bin. height registers (Standard height), and those in 4th column are for 4in. height registers. For Sin. height registers, multiply values in Co/. 2 and 3 by 13 For Sin. height registers, multiply values in Col 2 ana 3 bif 0.8_________ For 2~way deflection registers, add the vertical and horizontal deflection angles - together and multiply by 0.7. Select closest angle 'am in Col. I of Table 7 Fig. 3. Equivalent Length of Fittings (Continued) provided the building is reasonably well constructed and insulated. Windows and doors should be tight, and awnings should be supplied on the sunny side of the building. (See also Chapters 38, 39 and 43.) Conclusions drawn from studies4 conducted in the University of Illinois Research Residence, subject to the limitations of the test are: 1. An uninsulated building of ordinary residential type may require the equivalent of three tons of ice in 24 hr on days when the maximum outdoor temperature.reaches 100 F if an effective temperature of approximately 72 deg is maintained indoors. 2. The use of awnings at all windows in east, south, and west exposures may result in savings of from 20 to 30 per cent in the required cooling load. . 3. The cooling load per degree difference in temperature is not constant but increases, as the outdoor temperature increases.