TM 5-852-4/AFM 88-19, Chap. 4
the building will minimize frost penetration but usually
measured floor temperatures 6 in. from the inside wall of
cannot be relied on for design purposes. In some
the structure shown in figure 4-33 is presented in figure
41
4-34 .
Because the external temperature varied
winters snow cover at time of maximum freezing
constantly during the period of observation, true steady
conditions may be very small. Again snow will be absent
state conditions were not achieved. Figure 4-35 shows
if sidewalks are placed adjacent to the outside of the
floor temperatures vs distance from the interior wall
foundation wall and are kept shoveled or plowed and
determined by actual measurement at the same Loring
possibly if a large roof overhang is used. Sometimes
AFB building, compared with results predicted by flow
wind patterns near the building may blow the area
net analysis and electrical analog analysis and with
adjacent to the foundation wall essentially free of snow
adjusted comparative data from National Bureau of
cover.
Standards studies. The actual measured values show
(h) Insulation should be specified in
more rapid drop in floor temperature as the exterior wall
depths corresponding to commercially available
is approached than is predicted by the flow net and
dimensions. Avoidance of the necessity for field cutting
electric analog analyses. This difference is believed to
is especially advantageous if factory-enclosed insulation
be the
board is available, since a minimum of on-the-job
membrane resealing is then required. A record of actual
U. S. Army Corps of Engineers
Figure 4-34. Floor temperature 6 in. from wall vs daily average air temperature measured at Loring AFB, Maine41.
(Concrete slab 12 inches above grade; insulation is cellular glass 1 inches thick, 36 inches vertical length.)
4-49
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