Document ykn2e8M4aerw3DVjL6z1w0p5D

American Society of Heating and Ventilating Engineers Guide, 1930 Table 7. Hot Water Requirements for Apartment Buildings Claes Lavatories Hot*Wateh Fixtures pzs Apartment Bath Tube Shdwere Over Tube Kitchen gtnfrg Laundry Trays Ai A2 A2 A2 B1 C1 i 2 2 1 1 1 i 1 2 1 0 0 l l l l l l 2 2 2 2 2 1 requirement. Separate Showers Gallons Hot Watch ;FEfi AfAJZTOWT peb Maximum Bonn o 0 o 1 o 0 25 30 35 55 20 15 Table 8. Hot Water Requirements for Hotels Cuss Gallons Add for Kitchens feb Meal Capacity Hot Water PerH. W. per H. W, Fixture Fixture per Maximum Per Day per Day Hour Per Maximum Hour ' Add fob Laundbt Per Washer Per Piece per Day Per Washer per Day per Mftiiirmm Hour 1 * High-class transient______ Medium-class transient__ Apartment hotels________ 85 70 50 6.8 6.5 5.0 3.0 2.5 2.0 1.0 0.80 0.60 1.0 1.0 1.0 1200 1000 1000 250 200 200 Nolr.-IostaotaneoM demand rate lor laundry washers from 25 to SO gal. per minutT Table 9. Hot Water Requirements for Office Buildings Class Having hot water in public toilets onlv Having hot water in private offices as well as in public toilets - __ ____ ___ for sell-closing hot-water fixtures deduct Hoi Watsb ran Hot-Watzb Fnmmi Per Day Per Mti'mmm Hour 50 30 40% >5.0 3.0 25% Table 10. Hot Water Requirements for Hospitals Gallons used per average day..... ........................................................ Gallons used per maximum day..... .................................... --.......... Average maximum rate of flow for 15 min. in gallons per hour.-- Maximum rate of flow for 15 min. in gallons per hour Note.--The above values are based on Utility Demands of a Modern Hospital, by Larson, Nelson and Rose. See Journal, American Society of Heating and Ventilating Engineers. January 1928. Note.--The hot water used is 25 per cent of total water requirements. The above requirements are for. a hospital without a laundry. 402 Chapter 23--Water Supply Piping for Buildings fixtures can be taken from Tables 5 and 6. On the top story it will be necessary to use a lj^-in. branch to carry 60 gal. per minute with a pressure drop of 30 lb. but that at 30 ft. vertically from the supply, a lj^-in. branch pipe will carry 60 gal. per minute; therefore l}4-in. pipe could be selected for this branch. Assuming that the pressure drop in the main riser is 10 lb. per 100-ft. run and the pressure drop on the top story in the branch does not exceed 15 lb. in all and the static head for building 100 ft. as given in column 2 of Table 6 is 43.31 lb., making a total of 58.31 lb.; it will be seen that 75 lb. -- 58.31 lb., which equals 16.69 lb., is the amount of pressure over and above that required, and that this pressure can be utilized to overcome the friction drop in the main feed line running from the source of supply to the base of the riser. From Table 2 it is found that 240 gal. per minute will flow at the first story, and assuming that this water supply is to be carried in a main 300 ft. long, a 3J4-in. supply would be necessary according to Table 5. Table 11. Water Requirements for Hospitals* Total Wa'tbb Total Wateb Used' Ex* clusive of Amount Used in Toilets, Slop Sines, Softener Flush* mo and Refrigeration Cooling Cold Wateb Used Exclusive of Amount Used in Toilbtb, Slop Sinks, Softsneb Flush ing and RefbiGebation Cooling Per Patientb Per Fixture Per Patient Per Fixture Per Patient Gallons used per average day--......... Gallons used per maximum day........ Average maximum rate of flow for 15 min. in gallons per hour............. Maximum rate of flow for 15 min. in gallons per hour............................. 366 527 29 50 77 275 104 193 116 423 174 296 7 25 8 14 12 44 16 30 aThe values given are based on Utility Demands of a Modern Hospital by Larson. Nelson and Rose. See Journal, American Society of Heating and Ventilating Engineers. January 1928. (No laundry included.) bThe items in this column, include water used for flushing softeners and refrigeration condenser. Example: What pressure is required in the water supply main to give 15 lb. pressure at the uppermost fixture in a building where the riser is 100 ft. high and is located 75 ft. from the water main in a horizontal direction, when the other fixtures within the building are in use to their estimated average capacity? The answer; according to Table 5, is found to be 75.8 lb. at the inter section of 100. ft. vertical height and 75 ft. horizontal run. Note.--If only 10 lb. be required at the uppermost fixture, then 70.8 lb. would be the answer. WHEN THE HOUSE TANK IS ON THE ROOF If the tank is elevated above the highest fixture, similar computations will apply for branch connections and main risers except that the main riser will have its greatest diameter at the top. It will be seen that an elevation of 35 ft. or more will give the necessary 15 lb. pressure at the highest fixture and-that the pressure drop may be made equal to the static head from the top fixtures down, or 40 lb. per 100. 403