A visual inspection of Figure 2 (showing Test 1 : non-test zones at minimum flow with fan-powered box fans on) shows that the concentration in zones C and D rises faster than the relief air (the relief air, a dashed grey line, is a proxy for building average concentration).
Series fan-powered boxes: Their impact on indoor air quality and comfort.
It focuses on single duct VAV reheat systems, but most of the principles apply to other VAV system variations, such as dual duct and fan-powered box
This derivation is based on a tracer gas mass balance at the inlet to the fan-powered box. The concentration at the inlet is denoted [C.sub.fpb], the return air concentration is [C.sub.ret], and the zone concentration is [C.sub.z].
The air handlers serve 134 pressure-independent air terminal units (ATUs), of which 87 are parallel fan-powered boxes (FPB).
I want your guys to tear apart every fan-powered box
on one floor, and tell me what you find.
Using a sensible cooling coil on the induction port of a series fan-powered box
allows an interesting mix of control options.
Perimeter zones of the building are served by fan-powered boxes
with reheat coils.
Some designs with fan-powered boxes
in the floor keep the plenum at negative pressure relative to the space to draw return air back into the supply air and moderate its temperature.