Catalogue
WSHP-PRC020D-EN 9
Application Considerations
Equipment Risers
The riser provides an easy way to facilitate the water flow
through a multi-story building and the high-rise heat pump.The
high-rise heat pump is best applied to a building with identical
zones on each floor, and zones that are typically small. An
example building might include a hotel, dorm, condominium or
assisted living facility. With these types of buildings, the riser
column (external to the unit cabinet) can be stacked one on top
of the other.The piping installation for the entire HVAC system
becomes very simple to install because it is pre-measured, and
pre-fabricated at the factory.
Factory risers are available asType K (design special), L
(standard design), and M (standard design).The differences
between these types of materials is the wall thickness of the
copper. Table 1, p. 9 shows the wall thickness for the most
common diameters of risers. It is recommended for most jobs to
use type L or M copper.Type K risers are generally not necessary
for most high-rise heat pump applications.
The riser design contains threaded stubouts to facilitate
connection of the supply and return risers to the hose kits.The
hose kits are then connected to the water-in/out of the unit’s
chassis.
Note: Supply/return/drain risers that are ordered and supplied
through the factory may be ordered as insulated.
Drain risers are generally made of type M copper. If copper, drain
risers are used, the risers should be insulated since the typical
temperatures of condensate may cause the riser to sweat.
Table 1. Riser characteristics
Type K (special design)
Riser Size (in.) I.D. (in.) O.D. (in.) Copper Wall Thickness (in.)
1 0.995 1.125 0.065
1¼ 1.245 1.375 0.065
1½ 1.481 1.625 0.072
2 1.959 2.125 0.083
2½ 2.435 2.625 0.095
3 2.907 3.125 0.109
Type L (standard)
1 1.025 1.125 0.05
1¼ 1.265 1.375 0.055
1½ 1.505 1.625 0.06
2 1.985 2.125 0.07
2½ 2.465 2.625 0.08
3 2.945 3.125 0.09
Type M (standard)
Riser Size (in.) I.D. (in.) O.D. (in.) Copper Wall Thickness (in.)
1 1.055 1.125 0.035
1¼ 1.291 1.375 0.042