55
HORIZONTAL OR VERTICAL UNIT — VERTICAL COIL
REMOVAL (39LB,LC,LF,LH UNITS)
Item numbers are in Fig. 57 unless otherwise indicated.
1. Refer to Fig. 10 for service area requirements.
2. Disconnect piping (Item 6).
3. Horizontal Unit, 39LB and 39LC — On top panel (Item 4)
remove screws located directly above side panels (Items 2
and 7). Top panels may be removed from unit to provide
more workspace, but it is not required.
Vertical Unit, 39LF and 39LH — Through fan access door
(Item 2, Fig. 57), remove screws (Item 3, Fig. 57) holding
angle (Item 4, Fig. 56) to top of coil panels (Item 7, Fig. 57).
Remove rear panel (Item 17, Fig. 55) and remove baffle angle
screws (Item 5) holding top baffle to coil.
4. Remove side panel(s) (Item 7).
Vertical units may require support of fan section after
removal of side panels.
5. If accessory is present, remove accessory side panel (Item 1)
on left side of unit. Detach filter track support bracket if
upstream accessory is a filter.
6. Remove screws (Item 8) from inside baffle (Item 3). Leave
baffle attached to left side panel (Item 2).
7. Slide coil and header end baffle from unit.
8. Replace coil by reversing preceding Steps 1-7.
Changing Coil Hand
1. Electric heat coil hand cannot be changed.
2. The coil cover panel is not part of the coil. Remove cover
panel from end of unit. New holes must be cut in coil cover
panel. Original holes must be plugged and insulated. New
side panels may be necessary when changing coil hand.
NU-FIN COILS
The NuFin coil is airflow direction sensitive, especially when used
in dehumidifying applications. Hydronic versions are counterflow
circuited for full gravity draining when installed level.
Correct installation will result in the typical bottom inlet on leav-
ing air face and top outlet on entering air face of coil, a self-vent-
ing design. This will ensure cold air contact with cold water, and
warm air with hot water.
Coil repositioning for opposite hand application will compromise
one or more of these characteristics. However, there will be those
situations where this may prove acceptable.
As a general rule, a change from counterflow circuiting to parallel
flow for sensible heating and cooling applications will result in a
5% drop in net capacity per row of coil. In one and two row heat-
ing coils, the actual drop may not be measurable, thus of insignif-
icant consequence.
It is important that the airflow direction of the NuFin coil be ad-
hered to when latent cooling is possible. Significant moisture car-
ryover from the face of the dehumidifying coil will result if this
rule is violated, even at very low face velocities. The same result is
often experienced if after-market fin coatings are applied.
If a NuFin hydronic coil is installed with correct airflow, but oppo-
site piping hand, and counterflow is maintained, steps must be tak-
en to ensure that the coil is continuously vented, and that the water
velocity is maintained to prevent the coil from air-binding.
Hot or cold areas of the coil face (or otherwise broad temperature
differences and stratification) are usually indications that one or
more circuits are air-locked internally. This can result in coil
freeze-up (a condition NOT covered by warranty).
Refrigerant coils may be rotated for opposite hand applications,
maintaining the proper airflow direction.
Do not reposition the distributor(s), they will perform equally well
in upflow or downflow positions. When soldering expansion
valves to up-feed distributors, use the minimum satisfactory
amount of solder to prevent damaging the valve or plugging
passages.
Fig. 57 — Horizontal or Vertical Unit — Vertical Coil Removal (39LB,LC,LF,LH Units)
LEGEND
1
— Accessory Side Panel
2
— Left Side Panel
3
— Inside Baffles
4
— Top Panels
5
— Baffle Angle Screw
6
— Piping
7
— Right Side Panel
8
— Baffle Screw