International comfort products PHN524, Руководство по установке

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7
Step 5—Select and Install Duct Connections
The design and installation of the duct system must be in
accordance with the standards of the NFPA for installation
of non--residence type air conditioning and ventilating
systems, NFPA 90A or residence type, NFPA 90B and/or
local codes and ordinances.
Select and size ductwork, supply--air registers, and return
air grilles according to ASHRAE (American Society of
Heating, Refrigeration, and Air Conditioning Engineers)
recommendations.
The unit has duct flanges on the supply-- and return--air
openings on the side of the unit.
PROPERTY DAMAGE HAZARD
Failure to follow this warning could result in personal
injury/death or property damage.
For vertical supply and return units, tools or parts could
drop into ductwork. Install a 90 degree turn in the return
ductwork between the unit and the conditioned space. If
a 90 degree elbow cannot be installed, then a grille of
sufficient strength and density should be installed to
prevent objects from falling into the conditioned space.
Units with electric heaters require 90 degree elbow in
supply duct.
!
WARNING
When designing and installing ductwork, consider the
following:
1. All units should have field--supplied filters or accessory
filter rack installed in the return--air side of the unit.
Recommended sizes for filters are shown in Table 1.
2. Avoid abrupt duct size increases and reductions.
Abrupt change in duct size adversely affects air
performance.
IMPORTANT : Use flexible transitions between ductwork
and unit to prevent transmission of vibration. Use suitable
gaskets to ensure weather tight and airtight seal. When
electric heat is installed, use fireproof canvas (or similar
heat resistant material) connector between ductwork and
unit discharge connection. If flexible duct is used, insert a
sheet metal sleeve inside duct. Heat resistant duct
connector (or sheet metal sleeve) must extend 24--in.
(610mm) from electric heater element.
3. Size ductwork for cooling air quantity (cfm). The
minimum air quantity for proper electric heater
operation is listed in Table 2. Heater limit switches may
trip at air quantities below those recommended.
4. Seal, insulate, and weatherproof all external ductwork.
Seal, insulate and cover with a vapor barrier all
ductwork passing through conditioned spaces. Follow
latest Sheet Metal and Air Conditioning Contractors
National Association (SMACNA) and Air Conditioning
Contractors Association (ACCA) minimum installation
standards for residential heating and air conditioning
systems.
5. Secure all ducts to building structure. Flash,
weatherproof, and vibration--isolate duct openings in
wall or roof according to good construction practices.