Coil Piping and Connections
56
UNT-SVX07E-EN
Hydronic Coil Piping
Before installing field piping to the coil, consider the
following:
•
All coil connections are 5/8-inch O.D. (or 1/2-inch
nominal) female copper connections.
•
The supply and return piping should not interfere with
the auxiliary drain pan or condensate line. See
“Connecting the Condensate Drain” section for more
detailed information.
•
The installer must provide adequate piping system
filtration and water treatment.
•
Exterior condensate may be an issue (fan-coils only) if
field piping does not have a control valve. Refer to the
supply and return header locations in the “Dimensions
and Weights” section.
Note:
When using a field supplied piping package in a
fan-coil unit, allow sufficient room to install the
auxiliary drain pan. In addition, piping package
must not extend over edges of auxiliary drain pan.
Connecting Field Piping to Coil
1.
Remove the auxiliary drain pan, if it is in place, to
prevent exposure to dripping solder or excessive
temperatures.
2. Slide a 1/2-inch sweat connection coupling (installer
provided) onto the coil headers.
Note:
For vertical fan-coil units, push the main
condensate drain hose and overflow
condensate drain hose through the inside of the
chassis end panel to prevent them from getting
burned when making sweat connections. Be
sure to pull the hoses back through and route to
the auxiliary drain pan when the end panel has
cooled.
3. Solder the joint using bridgit lead-free solder (ASTM
B32-89) to provide a watertight connection. Avoid
overheating factory soldered joints when soldering
field connections to the coil to prevent leakage from
occurring.
4. Insulate all piping to coil connections as necessary
after connections are complete.
Note:
Maintain a minimum distance of one foot
between the reduction fitting for the
1
/
2
-inch
diameter line and the fan-coil unit piping
connections.
5. Install the optional auxiliary drain pan, which ships in
the accessory packet.
Water Piping Connections
Before installing water piping supply and return lines to
factory piping package, note the following items.
•
All piping connections are 5/8-inch O.D. (1/2-inch
nominal) female copper connections.
•
The fan-coil supply and return piping should not
interfere with the auxiliary drain pan or condensate
line. See
“Condensate Drain Connections,” page 56
for
more information.
•
The installer must provide adequate piping system
filtration and water treatment.
•
If the unit has a factory deluxe piping package, the
piping includes a strainer with a 20-mesh size screen,
which allows minimal protection from debris.
Therefore, clean the strainer regularly.
Note:
Maintain a minimum distance of one foot between
the reduction fitting for the
1
/
2
-inch diameter line
and the fan-coil piping connections.
Connecting to Factory Piping
1.
The factory installed piping package ships with
brackets to adequately support the piping during
shipment. Remove these brackets before connecting
water piping to the unit.
2. Close the piping end valves to the fully open position
to prevent damage to the valve seat during brazing.
3. Remove the auxiliary drain pan, if it is in place, to
prevent exposure to dripping solder or excessive
temperatures.
4. Solder water piping connections to supply and return
end connections. Avoid overheating factory soldered
joints to prevent the possibility of leakage.
5. Insulate fan-coil piping to auxiliary drain pan
connections and any piping that is not above the
auxiliary drain pan.
Condensate Drain Connections
1.
De-burr the pipe end before making the connection to
the drain pan.
2. Connect a 7/8-inch O.D. copper pipe or tube, with a 0.02
inch wall thickness, to the auxiliary drain pan. This
should be a mechanical connection that allows easy
removal of the auxiliary drain pan when servicing the
piping end pocket.
3. Slide the copper pipe over the drain pan nipple and
tighten the collar on the pipe with a hose clamp
(installer supplied).
4. Maintain a continuous drain line pitch of one inch per
ten feet of drain line run to provide adequate
condensate drainage. Extend the drain line straight
from the drain pan a minimum distance of six inches
before making any turns. The installer must provide
proper support for the drain line to prevent undue
stress on the auxiliary drain pan.
5. Install a secondary overflow drain line if necessary by
punching out the overflow drain nipple on the auxiliary
drain pan. Next, place a 3/8-inch inside diameter
