Document rxO9B7EMpeQa6awxeBb9bvbZv

624 CHAPTER 23 1958Guide Step 8. Mean Water Temperature and Upward Heat Flora a. Follow tlie procedure for Plaster Panels, Step 6. b. Find the heat flow upward from the panel (g,,) from Fig. 16. Add to the ther mal resistance of the slab to upward heat flow (r,,,), the resistance to heat flow (rnc) of any material between the upper surface of the slab and the space above to obtain the resistance (r,,) to be used m Fig. 16. The mean water temperature (fn) found and the air temperature of the space above the panel are the other two factors to be used. Step 7. Design Mean Water Temperature Select the highest mean water temperature (lmw) as the design mean water tem perature (Idaw) Step 8: Design Panel Output Follow the: procedure for Plaster Panels, Step 8. Step 9. Design Panel Area Follow the'procedure for Plaster Panels, Step 9. Step 10. Total Panel Output.. Follow the procedure for Plaster Panels, Step 10. Step 11. Fluid Circuit Follow the procedure for Plaster Panels, Step 11. Step 18. Boiler Size Follow the procedure for Plaster Panels, Step 12. Procedure for Plaster Wall Panels A design graph has not been prepared for wall panels but a design can be approximated using the equations of heat transfer from walls together with the thermal resistance properties of plaster ceilings from Table 2. The procedure for Plaster Ceiling Panels is used as a guide. Step 1. Heat Loss Follow the procedure for Plaster Ceiling Panels, Step 1. Step 8. Required Panel Output Follow the procedure for Plaster Ceiling Panels, Step 2. ` >';l Step S'. Panel Surface Temperature ,. Assume a trial panel surface temperature and determine the resulting heat out put from Figs. 9 and 10 as explained in the accompanying section of the-test. (Ad-, ditional heat flow due to the infiltration can be estimated from Fig. 12, if desired). Assume successive trial panel surface temperatures until the temperature is found at which the combined heat transfer from the panel equals the output determined in Step 2. Step 4- Reverse-side Heal Flow Follow the procedure for Plaster Ceiling Panels, Step 4. -t<?. Step 5. Panel Resistance Follow the procedure for Plaster Ceiling Panels, Step 5. i: . rf- Step 6. Mean Water Temperature For the required panel output found in Step 2, the panel resistance found in Step) 5, and the room air temperature, calculate the required mean water temperature as^. follows; 'J 'flaw -- Ip 4 rd(gj) (11); Panel "Heating :625 Step 7. Design Mean Water Temperature Follow the procedure for Plaster Ceiling Panels, Step 7. Step 8. Design Panel Output From equations, Step 6 and Figs. 9 and 10 find the panel output for design mean water temperature Idoi. by successive trials. Step 9. Design Panel Area Follow the procedure for Plaster Ceiling Panels, Step 9- Step 10. Total Panel Output Follow the procedure for Plaster Ceiling Panels, Step 10: Step It. Fluid Circuit ..F..o.l.l.o.w...the procedure for ,Plaster\ Ceilin.g Panels, Ste. p 11. Step 18. Boiler Size Follow the procedure for Plaster Ceiling Panels, Step 12. Procedure for Hot-Water Concrete Floor Panels (Slab-On-Grade)11 The procedure for designing a concrete floor, panel (slab-on-grade) will be illustrated by Example 2. Example 8: Three rooms, A, B and C, are to have a common water supply tem perature ; that is, they represent a single zone. They are to be maintained at 72 F air temperature when the outdoor air temperature is zero F. The floors in the three rooms are covered with heavy wall-to-wall carpeting, without a pad. Insulation which has a conductance of 0.4 Btu per (hr) (sq ft) (F deg) is placed along the edge of the slab and extends downward 2 ft below it. Step 1. Heat Loss Calculate the heat loss of each room, following, the recommendations contained in Chapter 12 Heating Load, but do not include any heat loss through the area covered by the panel. If very large rooms are involved, the rooms should be subdivided into areas having somewhat similar heat requirements, i.e., separate the interior areas requiring little or no heat input, from the exterior areas directly influenced by outside weather con ditions. Each such area should then be treated as a separate room for the purpose of design. Room dimensions, exposure, and calculated heat losses are as follows: Room Dimensions Feet Exposed Wall Feet Heat Loss Btu per Ji A* 11 x 12 x 8 . 23 3300 B 11x12x8 12 2500 , C 15 x 21 x 8 21 8000 I i90nlPare with Room A of Example 1. The rooms are the same except that in this example a lower heat hish asaIlme4 to permit the room to be heated by a floor panel alone without developing an inadmissibly hi Rixmi A UrfiU"e tcmPerature (Step 3). The lower heat loss is presumably the result of adding insulation Step . Required Panel Output carPhVitie beat loss of each room by the: maximum floor area in the room which foot fU3e<l as a heating panel. The result is the minimum heat output per square 01 P&nel that will satisfy the requirements of the room. The panel that req ires the highest output per square foot will generally control the design, because