WaterFurnace Envision Hydronic (NSW) - Manual (Page 8)

8
NSW INSTALLATION MANUAL
Field Connected Water Piping cont.
Earth Coupled Systems with Flow Center
Once piping is completed between the unit, flow center
and the earth loop, final purging and charging of the loop
is needed. A flush cart (at least a 1.5 HP or 1.12 kW pump)
is needed to achieve adequate flow velocity in the loop to
purge air and dirt particles from the loop itself. Antifreeze
solution is used in most areas to prevent freezing. Maintain
the pH in the 7.6-8.2 range for final charging.
Flush the system adequately to remove as much air as
possible. Then, pressurize the loop to a static pressure of
50-75 psi [345-517 kPa]. This is normally adequate for good
system operation. Ensure that the flow center provides
adequate flow through the unit by checking pressure drop
across the heat exchanger and by comparing it to the
figures shown in the Pressure Drop tables. Usually, 3 GPM/
ton [0.054 L/s/kW] L/s/kW or minimum 2.25 GPM/ton
[0.04 L/s/kW] of cooling capacity is needed in closed loop
earth-coupled applications
Typical Closed Loop Earth Coupled Installation
Line Voltage
Disconnect
Load Liquid
Connections
Vibration Absorbing
Mesh or Air Pad
P/T Plugs
Unit Connector Kits
with Insulation
Earth Coupled Loop
Piping with Insulation
Potable Water Systems
The NSW018 and NSW025 models can be equipped to
provide domestic hot water generation. An optional
factory-installed hot water generator coil may be provided
with the NSW040, NSW050, NSW060, and NSW075 to
assist with this process.
LOAD PUMP
HYDRONIC
LOAD
Source OUT
P/T Ports P/T Ports
Ball Valve
Dielectric
Unions
Dielectric
Unions
WaterFurnace
NSW Series
NOTES:
* A 30 psi pressure relief valve (Part No: SRV30) should be used in
hydronic applications.
** Vent valve or P/T port at highest point in return line prior to ball valve.
1-1/2 in.
FPT
Expansion
Tank
Air
Vent
Pressure
Gauge
30 psi
RELIEF VALVE
Air
Separator
FROM
HWG
TO
HWG
Back Flow Preventer /
Pressure Relief Valve
Source IN
GEO
STORAGE
TANK
PUMP
HOT
(Piped in
series to
an electric
water heater)
COLD
DOMESTIC
Dip Tube
Ball Valve
Vent Valve/
P/T Port**
Suggested Domestic Water Heater Hookup