10
NSKW INSTALLATION MANUAL
Field Connected Water Piping cont.
well, storm sewer, drain field, adjacent stream or pond,
etc.). Most local codes restrict the use of sanitary sewer for
disposal. Consult your local building and zoning departments
to ensure compliance in your area.
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 pump capable of 14 m
3
/hr @ 25 meters of head
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
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, 0.054 L/s per kW or
minimum 0.040 L/s per kW of cooling capacity is needed in
closed loop earth-coupled applications.
Ground Loop Design and Installation
This instruction manual does not cover the design and
installation of the ground loop system. WaterFurnace
recommends that all ground loops are designed using
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
NSKW06-17 kW heat pumps can be equipped with a
double-wall vented coaxial heat exchanger capable of hot
water generation (HWG). An optional factory-installed hot
water generator coil may be provided with NSKW08-17. The
temperature of the hot water produced by the heat pump
cannot be adjusted and will vary with the inlet temperature.
WaterFurnace recommends the use of a properly sized
buffer tank equipped with supplemental electric immersion
heaters in conjunction with all NSKW models used in an
HWG application. Immersion heaters must be capable
of heating the water to 60°C at a regular time interval
to prevent the build-up of bacteria such as Legionella.
Installations must meet minimum requirements outlined in
UK Domestic Heating Compliance Guide.
CAUTION: Hot water in excess of 60°C can cause
scalding.
GeoLink
TM
Design Studio (GDS) or another commercial
software package. Installers shall follow the guidelines
detailed in Microgeneration Certification Scheme (MCS)
Installation Standard MIS 3005 for designing ground loop
collectors. Additional guidance on ground collectors is
provided by International Ground-Source Heat Pump
Association (IGSHPA).
Hot Water Generator Connections
The heat reclaiming hot water generator coil is vented double-
wall copper construction and is suitable for potable water. To
maximize the benefits of the hot water generator a minimum
50-gallon water heater is recommended. For higher demand
applications, use an 80-gallon water heater as shown below or
two 50-gallon water heaters connected in a series. A geo storage
tank should not be used in this application unless it is plumbed
in a series with an electric water heater. The geo storage tank is
equipped with a single 4500 Watt element and will not be able
to provide adequate water heating if used as a standalone water
heater. Electric water heaters are recommended. Make sure all
local electrical and plumbing codes are met for installing a hot
water generator. The Envision NSKW is not supplied with an
internal circulator.
