Energy Recovery Ventilation; Cassette Replacement - Carrier AERO 39MN Installation, Start-Up And Service Instructions Manual

Energy Recovery Ventilation —
nance of the energy recovery cassettes includes inspection
and cleaning. On occasion, a part may need to be completely
replaced.
IMPORTANT: This unit contains an energy recovery
wheel heat transfer device. Proper service and mainte-
nance must be conducted as outlined below, or loss of
heat transfer and overall system performance will occur.
1. Remove and clean or replace filters in adjoining sec-
tion to the ERV wheel every 6 months or sooner, as
required.
2. Remove and wash ERV wheel (or individual seg-
ments, if so equipped) every 6 months, or every 3
months maximum for smoky or polluted environ-
ments. See instructions for removal and cleaning
details.
CLEANING — Periodic cleaning of the energy recovery
wheel will depend on operating schedule, climate and con-
taminants in the indoor air exhausted and the outdoor air sup-
plied to the building.
The wheel is "self-cleaning" with respect to dry particles
due to its laminar flow characteristics. Smaller particles pass
through; larger particles land on the surface and are blown
clear as the flow direction is reversed. Any material that
builds up on the face of the wheel can be removed with a
brush or vacuum. All sizes can be vacuumed.
Cleaning the removable segments (size 08-30) or the en-
tire wheel (size 03-06) will remove oil-based aerosols that
have condensed on energy transfer surfaces.
To clean removable segments (size 08-30):
1. Access the wheel from the exhaust fan side. This may be
easiest from the adjoining section, depending on the
type of section installed. If it is necessary to access from
the side of the wheel section, remove side panel as
shown in Fig. 112.
2. Unlock two segment retainers, one on each side of the
selected segment opening.
3. Use the tip of a flat screw driver to pop the segment out
of the wheel. Repeat for each segment.
4. Brush foreign material from the face of the wheel. Wash
the segments (or small wheels) in a 5% solution of non-
acid based coil cleaner (such as Acti-Klean) or an alka-
line detergent and warm water.
5. Soak the segments in the solution until grease and tar
deposits are loosened. (NOTE: some staining of the des-
iccant may remain and is not harmful to performance.)
For better cleaning action, rapidly run a finger across the
segment's surface to separate polymer strips.
6. Rinse dirty solution from segments and remove excess
water before reinstalling the segments in the wheel.
7. Replace the segments using the Segment Installation
and Replacement procedure on page 128.
To clean wheels (size 03-06) use the procedure and refer to
Fig. 113:
1. Remove the ERV section side access panel.
2. Remove the upper and lower wheel center partition
plates (1). This requires removing screws (a) of the up-
per and lower plate.
3. Remove the upper and lower (2) wheel retainer angles,
being careful wheel does not tip and fall out.
4. Slide wheel cassette out of frame (toward main AHU),
and out the side of the unit (3).
5. Follow Steps 2 through 4 of the cleaning procedure for
removable segments.
6. Reinstall the wheel into the section by reversing Steps 1-
Routine mainte-

CASSETTE REPLACEMENT

1. Inspect the replacement cassette for freight damage
2. Handle ERV cassettes with care. Lift by the bearing
3. Remove the ERV section side access panel.
4. Refer to Fig. 113. Remove the upper and lower wheel
5. Remove the upper and lower (2) wheel retainer angles,
6. Slide wheel cassette out of frame (toward main AHU),
7. The new ERV section may be mounted in any orienta-
8. To ensure that the beams are not racked, check that the
a39-4386
127
5.
upon receipt. Inspect the cassette frame, wheel assembly
and segments for damage and verify that the wheel turns
freely by hand (clockwise when viewed from pulley
side). Report any damage immediately to the freight
company.
support beam. Holes are provided on both sides of the
bearing support beams to facilitate rigging (Fig. 114).
center partition plates. This requires removing screws
(a) of the upper and lower plate.
being careful wheel does not tip and fall out.
and out the side of the unit (3).
tion. However, make certain that the frame remains flat
and the bearing beams are not racked as shown in
Fig. 115.
distance between the wheel rim and bearing beam is the
same at each end of the bearing beam, to within
inch (dimension A and B in Fig. 114). Bearing beam
racking of as little as .040 inches (Dim C in Fig. 115)
will cause the wheel to tilt
the diameter seals (Fig. 116) will compensate for up to
1 / in. of racking.
4
Fig. 112 — Remove Side Baffles
/ of an
1
4
3 / in. at the rim. Adjusting
16