Greenheck Fan Vektor-ERS Energy Recovery Plenum Laboratory Exhaust 474118 - Manual (Page 8)

8 Vektor ERS-MD Energy Recovery Plenum Laboratory Exhaust
Drain Trap
Coils are provided with a stainless steel drain pan
with 1 1/4-inch male NPT drain connection. A drain
trap must be connected to the drain connection to
allow excess water to flow out of the drain pan. More
importantly though, due to the negative internal static
pressure of the coil compartment, installing the drain
trap prevents outdoor air from being pulled into the
drain pan and consequently forcing water out of the
pan and into the unit.
To ensure the drain trap works properly, the trap
height must account for the difference in static
pressure between ambient conditions outside the
unit and the internal negative pressure of the coil
compartment.
Refer to local codes to determine drainage
requirements. If draining onto roof, place a drip pan
below drain to protect roof. If draining onto roof is
not acceptable, a drain line must be attached to the
trap. The drain line must be pitched away from the
unit at least 1/8-in. per foot. On longer runs, an air
break should be used to ensure proper drainage.
Local codes may require drainage into a waste water
system.
Drainage problems not only occur from improper drain
trap design, but also from lack of maintenance of
the cooling coil compartment. Algae can form in the
drain pan and trap
and cause reduced
water flow, which can
result in backup into
the system. Regular
maintenance will
prevent this from
occurring. If the
drains have a clean-
out opening, be sure
to close the opening
after cleaning.
Coils
Installation of Water Coil Piping
Guidelines for the installation of the coil have been
provided to ensure proper performance of the coils
and their longevity. These are general guidelines
that may have to be tailored to meet the specific
requirements of any one job. As always, a qualified
party or individual should perform the installation and
maintenance of the coil. Protective equipment such
as safety glasses, steel toe boots and gloves are
recommended during the installation and maintenance
of the coil.
All field piping must be self-supporting. System piping
should be flexible enough to allow for the thermal
expansion and contraction of the coil.
Water Coil Installation Recommendations
1. Piping should be in accordance with accepted
industry standards. Always use a back up wrench
on the coil connections when attaching the piping
to the coil if pipe thread connections are utilized.
2. Connect the water supply to the bottom
connection on the air leaving side and the water
return to the top connection on the air entering
side.
3. The air vent at the uppermost point should be
temporarily opened during system start-up to
release all of the air from the coil. To maintain
heat transfer capacity, periodically vent any air in
the coil.
4. Water coils are not normally recommended for
use with entering air temperatures below 40°F.
Glycol solutions or brines are the only freeze-safe
media for operation of water coils for low entering
air conditions.
5. Two position control valves, modulating valves,
three way valves or a combination of these
controls can accomplish control of water coils.
Follow the recommendations of the control
manufacturer regarding types, sizing and
locations. Face and bypass dampers may also
be used, but do not close off tightly. Air leakage
in cooling applications has no appreciable
affect. In heating applications, however, the air
temperature may rise several degrees and should
be considered in system design. Low leakage
dampers may be required.
NOTE
A conservative method of trap design is to add
1-1/4 inches minimum to total static pressure.
RECOMMENDED DRAIN TRAP DESIGN
(TRAP BY OTHERS)
NEGATIVE PRESSURE TRAP
FAN BYPASS
AIR PLENUM
ENERGY RECOVERY
PLENUM
SUBFLOOR SUBFLOOR
1.25 NPT
.75 NPT
H = TSP + 1¼ inch minimum
TSP = Total Static Pressure
H/2
1¼ inch minimum
TSP
*BASED ON STANDARD
VEKTOR ERS CURB HEIGHTS
* *
ROOF
CURB
ROOF
CURB
Note: A conservative method
of trap design is to add
1¼ inch minimum to total static
pressure
H/2 H
FAN OFF
14.750 14.000
NOTE: INSULATION OR OTHER MEANS
OF FREEZE PROTECTION MAY BE
REQUIRED IN CERTAIN CLIMATES