Pressure drop across the small fan, and resulting flow velocities in the two 2" pipes (the anemometer internal diameter is closer to 2.25", I take an area of 25 cm2.

ps version

Here are the temperatures (in °F), pressures (in mm Hg), and flows (in m/s) around the system, with no heat loads applied. The measurements near the MVD are taken at the point where the black hose connects to the lexan air guides.
The pressure measurements were taken with a Wallace and Tiernan differential pressure gauge, 80 mm Hg Max scale.


ps version

1) Here is the same set of measurements, displayed in table form:

Power:
Variac:
HP:
Sorensen:
total 		0 VAC into 25.3 Ohms
0 VDC into 129.4 Ohms
0 VDC into 7.7 Ohms
0 W
  Plenum side Heat Exchanger Box Enclosure side
Heat exch. exit F=14.4
T=42
P=9.9 		  F=3.5
T=43
P=9.6
  dQ=61W loss in pipes dQ=44W
MVD entry T=45
P=6 		  T=52
P=1
in MVD   MVD T=54
P=0.5
  dQ=61W gain thru enclosure->
<-from MCMs 		dQ=10W
MVD exit T=48
P=-2.7 		  T=54
P=-2.7
dQ dQ=121W loss in pipe dQ=0W
filter entry T=54
P=-3.5
  filter can
fan entry P=-3.5
  fan
fan exit P=9.4






1) Here is the same set of measurements, with the following heat loads applied:

Power:
Variac:
HP:
Sorensen:
total 		57.9 VAC into 25.3 Ohms
49.1 VDC into 129.4 Ohms
14.6 VDC into 7.7 Ohms
179 W
  Plenum side Heat Exchanger Box Enclosure side
Heat exch. exit F=13.2
T=41.5
P=7.2 		  F=3.3
T=43
P=8.3
  dQ=57.4 W loss in pipes dQ=39.4 W
MVD entry T=44.6
P=5.1 		  T=51.1
P=0.7
in MVD   MVD T=56.5
P=0.3
  dQ=387 W gain thru enclosure->
<-from MCMs 		dQ=41.2 W
MVD exit T=65.5
P=-2.3 		  T=60.0
P=-2.3
dQ -40.7 W loss in pipe +15.3 W
filter entry T=63.3
P=-3.0
  filter can
fan entry P=-3.0
  fan
fan exit P=8.1






2) power 1/4 of the previous:
Power:
Variac:
HP:
Sorensen:
total 		29 VAC into 25.3 Ohms
25 VDC into 129.4 Ohms
7.3 VDC into 7.7 Ohms
45 W
  Plenum side Heat Exchanger Box Enclosure side
Heat exch. exit F=13.2
T=41.2
P= 		  F=3.4
T=43.2
P=
  dQ=48W loss in pipes dQ=37W
MVD entry T=43.8
P=5.1 		  T=51
P=0.5
in MVD   MVD T=53
P=0.3
  dQ=152W gain thru enclosure->
<-from MCMs 		dQ=18W
MVD exit T=52.0
P=-2.3 		  T=54.8
P=-2.3
dQ dQ=74W loss in pipe dQ=6W
filter entry T=56
P=
  filter can
fan entry P=
  fan
fan exit P=






3) Rachel's power settings:
Plenum: 272W (Variac)
Radial MCMs: 48W (HP)
powr/comm boards: 36.4W (Sorenson)

Power:
Variac:
HP:
Sorensen:
total 		82.5 VAC into 25.3 Ohms
49.4 VDC into 129.4 Ohms
16.6 VDC into 7.7 Ohms
324 W
  Plenum side Heat Exchanger Box Enclosure side
Heat exch. exit F=13.0
T=43.8 		  F=3.3
T=45.0
  dQ=48W loss in pipes dQ=37W
MVD entry T=46.3   T=53.8
in MVD   MVD T=59
  dQ=691 W gain thru enclosure->
<-from MCMs 		dQ=119 W
MVD exit T=84.2   T=79.6
dQ dQ=-195W loss in pipe dQ=-28W
filter entry T=73.5
  filter can

Last update 8 Mar 99 - HvH back