104 Am.

OSGOOD-BRADLEY BUILDING Grafton and Franklin Streets Worcester, Mass.

Johnson Service Company Control Equipment either hot or cold.

AMERICAN SOCIETYOF BEATING & IYENTI1ATIN6 ENGINEERS GUIDEJ923 ; AMERICAN SOCIETYOF BEATING & YENTIEATIN6 ENGINEERSGDIDE.19230 Instead of using a certain number of air changes as a basis for esti mating infiltration losses many engineers use the lineal feet of window and outside of door cracks.

i American Society of Heating and Ventilating Engineers Guide, 1924-25 and infiltration calculations cannot be based with great certainty bn this curve.

1924-25of andAmerican Society Heating Ventilating Engineers Guide, TABLE 38.

ofAmerican Society Heating and Ventilating Engineers Guide, 1924-25 TABLE 51.

Air Conditioning W.

Kewanee Boiler Company Boilers 8g 3s O il s l^sSs3:=2',,f!

Aerofin Corporation Heating Surface SIZE REDUCED FROM .THIS POINT ON /IN ACCORDANCE 'WITH STANDARD VACUUM PRACTICE For Vacuum Return Line System Aerofin Units installed three-high, tubes horizontal, showing uses of pressed steel supporting legs.

American Society of Heating and Ventilating Engineers Guide, 1925-26 The percentage of air recirculated may be varied to suit the seasonal changes so as to conserve heat in winter and refrigeration in summer.

*X < 3O O t o 33 3 C 3o CO P 3C o zn \J O ^ c* <3 > O in cO T3 O O o<j 'js\ < rs -o t Ot i i "b LU or: j-LJ CQ ACCIDENT PREVENTION MAN UAL for Industrial Operations : EDITION ; PLEASE CO :.QT r$vv.s 7> 'ijNOOd 'A'Cdi CLi7 7 S'-;; r t .- "V NATIONAL SAFETY COUNCIL JChicago, Illinois 606, 3na ma rr *0- U-// dusts.

SC-ASHVE-003 CODE of ETHICS for ENGINEERS ENGINEERING work has become an increasingly important factor in the progress of civilization and in the welfare of the community.

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