6
EGW05-SWHPEG-20140724
TM
TM
Return Air
The unit will operate most efficiently in a natatorium where the supply and return openings are placed diagonally
opposite each other. All ducting should be done in accordance with acceptable practices. Return air ducts in the section
just prior to entering the unit return air opening and elbows in both the return and supply air ducts must comply with the
guidelines set forth in SMACNA HVAC Duct Construction Standards Metal and Flexible – Third Edition, Chapter 4.
Ductwork Design
All supply and return duct work to the unit should be installed such that no condensate occurs on the duct work. Duct
turns and transitions must be made carefully to keep friction losses to a minimum. Duct elbows should contain splitters
or turning vanes and avoid short radius fittings.
Duct work that is connected to the fan discharge should run in a straight line with proper transitions, and minimum
distances to elbows as recommended by SMACNA and should not be reduced in cross-sectional area. Never deadhead
the fan discharge into the flat side of a plenum.
Duct work attached to the PoolPak™ unit return air connection must be done in accordance with SMACNA
recommended standards and /or generally accepted industry practice.
Supply and return duct work should have all seams sealed before applying insulation to the exterior of the duct work.
The insulation’s seams must be sealed, wrapped, and mastic coated. Use of pre-insulated duct work (interior) is
acceptable if it meets local codes; however, all seams must be sealed prior to startup.
Air Distribution
Supply outlets and return grilles should be carefully placed to avoid short-circuiting in the space. Short-circuiting
creates stagnant areas where humidity and temperatures may build up to undesirable levels, reducing the effectiveness
of the PoolPak™ System. Return grilles can be placed high in the space to reduce return ductwork, however removal of
chloramines from the occupied area has become much more of a design consideration and so low returns are favored by
poolroom designers.
Supply air should be directed 45 degrees up and down (most of the air will be directed downward) toward exterior walls,
windows, skylights, and other areas where stagnant conditions could cause humidity buildup and condensation problems
or drafts (see Figure 1-4). The end result of the supply air ducts is to wash the surfaces of the pool room that are prone to
condensation with the warm, dry supply air.
Figure 1-4. Supply Air Proportions
20% OF SUPPLY
AIR DIRECTED
ALONG CEILING
80% OF SUPPLY
AIR DIRECTED
DOWN WALLS
WINDOW
SURFACE
12”
