Trane OABE OADE OAKE OANE (Water Source Heat Pump) Catalog
OAU-PRC003A-EN
23
Application Considerations
Acoustical Considerations
Proper unit placement is critical to reducing transmitted sound levels from the OAU to the building.
Therefore, consider acoustic concerns during the design phase and place the unit accordingly. The
most economical means of avoiding an acoustical problem is to place the unit(s) away from
acoustically critical areas. If possible, do not locate units directly above areas such as: offices,
conference rooms, executive office areas, and classrooms. Instead, ideal locations to consider are:
over corridors, utility rooms, toilets, or other areas where higher sound levels directly below the
unit(s) are acceptable.
Therefore, consider acoustic concerns during the design phase and place the unit accordingly. The
most economical means of avoiding an acoustical problem is to place the unit(s) away from
acoustically critical areas. If possible, do not locate units directly above areas such as: offices,
conference rooms, executive office areas, and classrooms. Instead, ideal locations to consider are:
over corridors, utility rooms, toilets, or other areas where higher sound levels directly below the
unit(s) are acceptable.
Follow these basic guidelines for unit placement to minimize sound transmission through the
building structure.
building structure.
1.
Never cantilever the compressor side of the unit. A structural cross member or full perimeter
roof curb, supported by roof structural members, must support this side of the unit.
roof curb, supported by roof structural members, must support this side of the unit.
2. Locate the unit’s center of gravity close to or over column or main support beam.
3. If the roof structure is very light, replace roof joists by a structural shape in the critical areas
described above.
4. If several units are to be placed on one span, stagger them to reduce deflection over that span.
It is impossible to totally quantify the building structure effect on sound transmission because it
is dependent on how the roof and building members respond to the OAU’s sound and vibration.
However, following the guidelines listed above will help reduce sound transmissions.
is dependent on how the roof and building members respond to the OAU’s sound and vibration.
However, following the guidelines listed above will help reduce sound transmissions.
Clearance Requirements
Follow the recommended unit clearances to assure adequate serviceability, maximum capacity,
and peak operating efficiency. Reducing unit clearances may result in condenser coil starvation or
warm condenser air recirculation. If the recommended clearances are not possible on a particular
job, consider the following:
and peak operating efficiency. Reducing unit clearances may result in condenser coil starvation or
warm condenser air recirculation. If the recommended clearances are not possible on a particular
job, consider the following:
•
Do the clearances available allow for major service work, such as changing compressors or
coils?
coils?
•
Do the clearances available allow for proper outside air intake, exhaust air removal, and
condenser airflow?
condenser airflow?
•
If screening around the unit is used, is there a possibility of air recirculation from the exhaust
to the outside air intake or from condenser exhaust to condenser intake.
to the outside air intake or from condenser exhaust to condenser intake.
Review any actual clearances that appear inadequate with your local Trane sales engineer.
When two or more units are placed side by side, increase the distance between the units to twice
the recommended single unit clearance. Stagger the units for these two reasons:
the recommended single unit clearance. Stagger the units for these two reasons:
1.
To reduce span deflection if more than one unit is placed on a single span. Reducing deflection
discourages sound transmission.
discourages sound transmission.
2. To assure proper exhaust air diffusion before contact with the adjacent unit’s outside air intake.
Duct Design
It is important to note that the rated capacities of the OAU can be met only if the unit is properly
installed. A well-designed duct system is essential to meet these capacities.
installed. A well-designed duct system is essential to meet these capacities.
Satisfactory air distribution throughout the system requires an unrestricted and uniform airflow
from the OAU discharge duct.
from the OAU discharge duct.
However, when job conditions dictate installation of elbows near the OAU outlet, using guide vanes
may reduce capacity loss and static pressure loss.
may reduce capacity loss and static pressure loss.