Document QgMaVdm6k8jBL2wV1MYZZRv7L

'"tnsvfatksrt \ ,-Top floor 9iob VJmmrnm < "'barter 19,ft \0ettw* 's*ob The usuot design of ffcerfng-raom floor consists of t*0 concrete slobs separated by o thick layer of invitation nraw/*r ---- /.. r .| 1 L,^rprrnsio^ JCCWvf/vwor- A*^w ftrt+r r Yj )T\^C/rcuAaf/rn pump J --- M&rrrtitsg foil n fltoor>^ 1 r_..Ujageni t . ... But the better the floor l lion, the slower the chilling ccti> the earth. For this teaaon, intu engineer# usually specify 8 in. o( far tero-F room# end 10 in. at on in. for lower temperatates. Seateeet CHocf. Because soil ter mure and moisture content loflt ice formation, the season* ptol govern effective (ce buildup. This account lor the strata formation o most clear ice between thin layet earth. Experience indicates that once formed does not melt unless floor is,wormed up for some time. Jo one foatonee the floor had bud . under a -^-30 F fretting tunnel. 5* heal was applied, through double*' pipes driven under the slab, for era) weeks before the ice melted * the earth dried enough to eliow the fl to eettle into position. Mthed of Comoction. P solution to the problem is t thicker insulation nor drafpsg though both will delay floor i A method must be used that kee earth contact temperature above ing (32 F). Three methods have been sucet 1. Lay eJeetriotMteat/ng cable - -------------WOTMIK&___as.) 7 Heat, exchanger, control volvei, expansion tank, circulating pvmo and connect ing pipe can be mounted outside freezing room on a wall above other moehtneiy 9t imi earth under tha concrete slab an thermostatic control, keep the above (reeling. This la usually t aomie&f because of the power cost 2. Raise floor level to provide > fOWCR Ms? |W* Insulation*^ Concrete*^ iV tYarming pipes'*"' "'Bottom concrete slab Earth-' lVuters o KI9H floor Is net objectionable, speco unde- II need* ptrmOs summer olr circulation to worm the floor C Worming pipes Imbedded In lower slob odd enough foot v to keep lee from forming In the ground under the concrete -fc sir ducts, Fig. 4. Air circulating lL ta&rcction warms the concrete slob jrioj summer and prevents deatrueaccumulation. This method b objectionable because ol the higher itasd extra construction eojta. X.J, Install s pipe-warming coil In the tattoo concrete slab, as in Fig. 1 and S Estate the %-fn. wrougbt-iron pipes Fin (a place. By circulating a non. State solution warmed to about 45 F, Etta earth temperature can be held at 40 "F, thus positively preventing Ice I fnution. Construction photograph, c/Ig. 1, shews the warming pipes In MocstioB before pouring the bottom con. I'otts slab. Ths fluld-warming circuit consists ei a heater, circulating pump and auto matic temperature controls. Fig. 6 and 7. 'Because of cost tha fluid, selected for the lee-cream plant of Penn Dairies Inc, Lancaster, Pa., is No. 2 fuel oil although rodiolor nonfreete solutions or transformer oil could be used. jacket water from refrigerating ma chines is also suitable as a source of beat tor the exchangers. This water is usually either thrown away or cooled for reuse, so extracting its heat for eonh warming may reduce operating expenses. Floor-insulation cost Is another econ omy of major importance that can be taken advantage of.. With a pipe-warm ing system, 6 in. of corkboard is Justifi able on sero-F floors Instead of 8-in., or more which is normally called for. Refrigeration loss through 6 in. of cork In the floor is so small that a thicker layer is not economically justi fied. Saving in insulating costs is usu ally more than sufficient to pay for 0 pipe-warming system, besides assuring 0 troublefree insulated floor. Temperatures observed on a new installation of a --10 F room were: Time Earth temp July (started) .............. 60 F August ........................... 50 F September ......................... 40 F October.............. ............Heating started December...................... 42 F $ flow up through the floor depends on the temperature to katp the ground from freezing, yet does not increase the a tap ocraci the tniutation. Coroful design odds enough heot temperature differential beyond 0 sofa, econqmtcul point (1911 9J