%0 U.S. Federal Government Document %0 Book %0 E-Resource %A Garrivier, P. %E United States. National Bureau of Standards %I National Bureau of Standards : For sale by the Supt. of Docs., U.S. Govt. Print. Off. %D 1972 %G English %B NBS technical note %B United States National Bureau of Standards Technical note %T Use of an air-to-air heat exchanger to recover heat from air exhausted by mechanical ventilation