Nortec NH Series, Installation Manual

Page: 37 / 110

10-10
Page 21
2006-09-15
(2) Duct vertical clearance requirements for standard steam distributors are as follows:
(a) ASD - 8 in. vertical duct height for 1st ASD
- 5.5 in. additional duct height for each additional ASD
= ROUNDDOWN (‘DuctHeight’ - 8 in.)/5.5) + 1
(b) BSD - 10 in. vertical duct height for 1st BSD
- 6.375 in. additional duct height for each additional BSD
= ROUNDDOWN (‘DuctHeight’ - 10 in.)/6.375) + 1
(c) CDS - 14 in. vertical duct height for 1st CSD
- 9 in. additional duct height for each additional CSD
= ROUNDDOWN (‘DuctHeight’ - 14 in.)/9) + 1
NOTE
These requirements apply to arrangements of multiple distributors ONLY. Diagonal
arrangements utilize an alternative method.
E. LOCATION OF STEAM DISTRIBUTORS WITHIN AN AIR HANDLER
(1) Humidify after the heating coil (H/C) so that absorption will occur before the cooling
coil (C/C). If steam condenses on the cooling coil, any excess water will be drained
away. There is little chance of condensation on the blower, blower motor, or fan
isolation components, especially if you use a modulating high limit humidistat. All steam
distributors should be a minimum of 8 in. from the H/C and evenly spaced. If
downstream wetting is a problem, add more steam distributors. (See Figure 17).
F. DISTRIBUTOR ABSORPTION
DISTANCE
(1) The water vapor discharged from
the steam distributor must be
adequately mixed with air to
prevent condensation on
downstream components. Consult
the design engineer or
Engineering Manual H-100.
G. TYPICAL APPLICATIONS
(1) Representations of typical
applications are found in Figure 18
and Figure 19.
H. DISTRIBUTOR DIMENSIONS
(1) Distributor dimensions for the
various distributor models can be
found in Engineering Manual
H-100, Chapter 10-30.
Figure 17. Best Location for Multiple Steam
Distributors