OMEGA | WATER SOURCE HEAT PUMPS                                                                 OMEGA-VSHP.F-IOM-1907 
 
 
7  www.omega-heatpump.com   
 
 
 
4.Swaged sections are approximately 3 inches deep. 
Risers should be inserted at a depth of approximately 2 
inches into the 3 inch deep swage. Confirm risers pene-
trate at a minimum of 1 inch into the swage. Do not allow 
the riser tailpiece to bottom out fully into the 3 inch deep 
swage.  This will allow for floor to floor variations, other-
wise riser overlap may not be sufficient on upper floors. 
See Figure 6. 
5. Align and center riser positions in the pipe chase and 
level cabinet as necessary. 
6. Secure the cabinet to the floor. Cabinet base comes 
with factory mounted neoprene pads. 
7. Center the riser stub-outs in the cabinet openings to 
allow for riser expansion and prevent contact with cabi-
net sheet metal. Prevent riser stub-outs from contacting 
sheet metal pass through otherwise damage to stub-
outs may occur, resulting in serious water damage. See 
Figures 7 & 8. 
8. Secure risers to building structure as per engineering 
design specifications. Do not allow the risers to be sup-
ported by the cabinets. Field supplied riser compensa-
tors are required if the temperature range of the system 
exceeds the expansion and contraction limit. 
9. Using industry accepted soldering and brazing stand-
ards and materials to solder or braze the riser joints. 
10. Connect supply ducts and discharge grilles. See 
Figure 11. 
11. Optional Fresh Outside Air Duct details are shown in 
Figures 12 & 13 when connecting to remote ERV. 
RISER LOOP  
Servicing 
To enable system flushing, servicing and balancing of 
supply and return risers the following field supplied com-
ponents are required: shut-off valves, drain tees and 
drain valves, and flow measuring devices.  Refer to the 
job site engineering design specifications and building 
drawings for more detailed information. 
 Flushing & Cleaning 
Once the riser system is complete the riser system must 
be flushed, cleaned and chemically treated.  Do not con-
nect chassis to the water circulating system when flush-
ing is being conducted to prevent debris and fouling of 
the water side components of the chassis (i.e. auto bal-
ancing valve, auto shut-off valve, coaxial coil). 
Do not flush and clean riser system with chas-
sis units connected. Do not allow the flushing 
and cleansing solutions to flow in the chassis 
water coil.  Damage to water components may 
occur. 
Supply and return pipes must be interconnected, at a 
minimum in the top and bottom units of each riser, with 
factory supplied hoses to properly flush system and en-
sure adequate elimination of foreign material and clean-
ing of riser system. 
1. Use only clean water to fill water circulation system. 
Fill the water circulating system at the municipal water 
makeup connection with all air vents opened.  
2. After air vents have been sequentially closed and riser 
system is primed begin water circulation of the system to 
purge remaining trapped air bubbles. 
3. Shut off the circulating pump and open all the drains 
and vents to completely drain the system. 
4. The riser system should be cleaned after the initial 
flush and flushed a second time to adequately rinse the 
riser system of cleaning solution. 
Chassis installation is permitted once the riser system is 
thoroughly flushed, cleaned, and commissioned by the 
riser treatment company and contractor. 
RISER SYSTEM LOOP TEMPERATURE 
Correct  riser  system  loop  temperature  settings  are  im-
portant for optimal unit operation.  Temperatures outside 
of the recommended range will affect overall unit operat-
ing  performance  (capacity  and  efficiency),  long  term 
reliability and sound performance. 
Cooling Season  
In  cooling  mode  recommended  riser  loop  temperatures 
should be maintained between 85
o
F to 90
o
F. Higher riser 
loop temperatures reduce unit cooling capacity and effi-
ciency and increase sound levels. Lower riser loop tem-
peratures will increase unit  operating efficiency. 
Operation of riser loop temperatures above 110
o
F EWT 
is  not  permitted,  and  sustained  operation  above  100
o
F 
will  reduce  cooling  capacity  and  may  increase  unit 
sound  levels  and  maintenance  costs.  If  loop  tempera-
tures  are  close  to  permissible  levels,  riser  loop  can  ex-
perience water temperature spikes above recommended 
during peak demand loads. Refer to Table 2: Unit Oper-
ation Limits. 
Heating Season 
In heating mode  riser loop  temperatures must be main-
tained within 55
o
F to 90
o
F for standard range operation. 
For Geothermal Range operation  the  system loop must 
contain an appropriate glycol mixture where system loop 
temperatures are  low  enough  that  could  result  in  freez-
ing  of  the  water  circuit.  For  low  temperature  operation 
units must come with factory Geothermal Range option. 
Do  not  operate  riser  system  below  20
o
F  EWT  due  to 
reduced heating capacity and efficiency. See Table 2.