INSTALL THE DRAIN
An external or an internal drain must be attached to
the drain connector.
External Drain
Attach a 90° PVC elbow to the unit’s female 3/4″NPT
drain connector. Use the other end of the elbow to
run a 3/4″Sch.40 PVC pipe through the knockout
holes of both the wall plenum and the architectural
louver to the outside. Seal the gap between the
plenum hole and PVC tube. See the Installation
Instructions in the RAVAL1.
Internal Drain
Attach PVC to the unit’s female 3/4″NPT drain
connector. See the Installation Instructions in the
RAVAL1. Local codes may apply.
2DUCTWORK
Prepare the closet ductwork for later connection to
the case.
The total flow rate (CFM) and external static pressure
(ESP) available can be estimated from the chart below.
Use these charts to select your fan speed setting. The
collar on top of the case accepts standard 10″duct.
Pull all duct tight. Extra duct slack can greatly increase
static pressure.
CAUTION: Flex duct can collapse and cause airflow
restrictions. Do not use flex duct for 90° bends or
unsupported runs of 5 ft. or more.
3
Installation Instructions
19
Your airflow should be balanced based on many
factors, such as available ESP, room CFM, and
ductwork. Consult an HVAC engineer for proper
applications. External static pressure (ESP) can be
measured with a manometer or pitot tube. Once this
ESP is established, you can calculate the CFM using
the above chart.
CFM Recommendations
9,000 BTU 12,000 BTU 18,000 BTU
275 300 325 350 375 400 450 500 550
•••
• = Recommended Mid Range
Higher CFMs tend to increase Sensible capacity,
enhance room circulation and increase duct noise,
while lower CFMs tend to increase Latent capacity
and reduce noise.