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THERMA-FUSER
BALANCING
BALANCING (TF-C, TF-CW AND TF-HC)
VAV systems are balanced for design air volume at maximum
air flow and systems using Therma-Fuser VAV diffusers are
no exception.When all the Therma-Fuser diffusers are set for
maximum air flow by fully opening them, the system is really
a constant air volume system and is balanced as a constant
volume system. Balancing dampers are best located at the
takeoff before the runout to the Therma-Fuser diffuser.
1.
Prepare system for balancing. (Make necessary checks
for diversity, fan capacities, fan rotation, miminum outside
air requirements, duct leaks and static pressure controller
design setting. Set outside air control damper for minimum
air and return air control damper for maximum air.)
2.
Open Therma-Fuser diffusers.
a.
Open appearance panel.
b. Unhook tension spring from bracket adjacent to
cooling thermostat. See Fig. 2.
c.
If perimeter blades do not immediately drop to open
position, turn the control plate slightly until they open.
d. Close appearance panel.
NOTE:
If the Therma-Fuser diffuser is equipped with a R-Ring
(Ceiling plenum relief ring) do not disconnect the spring. Use
temporary balancing stops made of wood supplied with
the diffuser to hold the blades open the proper distance for
balancing. Thickness of the stop will depend on the size of the
R-Ring used.
3.
Start fans, adjust system for 100% air flow and make
system checks. (Measure static pressure across filters and
coils and at sensor for static pressure controller. Measure
supply, return and branch duct air flow.)
4.
Place a direct reading diffuser balancing hood over the
face of each Therma-Fuser diffuser and adjust damper at
duct takeoff to obtain maximum design air volume.
5.
Return Therma-Fuser diffusers to operating condition.
a.
Open appearance panel.
b. Attach tension spring to bracket (removed in step 2b).
c.
Close appearance panel.
6.
Return the remainder of the system to operating condition.
return air control damper for maximum air.)
2. Open Therma-Fuser diffusers.
a. Open appearance panel.
b. Unhook tension spring from bracket adjacent to cooling
thermostat. See Fig. 2.
c. If perimeter blades do not immediately drop to open posi-
tion, turn the control plate slightly until they open.
d. Close appearance panel.
Note: If the Therma-Fuser diffuser is equipped with a R-Ring
(Ceiling plenum relief ring) do not disconnect the spring.
Use temporary balancing stops made of wood supplied with
the diffuser to hold the blades open the proper distance for
FIG. 2 REMOVE SPRING TO DROP BLADES OPEN FOR BALANCING
balancing. Thickness of the stop will depend on the size of
the R-Ring used.
3. Start fans, adjust system for 100% air flow and make system
checks. (Measure static pressure across filters and coils and at
sensor for static pressure controller. Measure supply, return
and branch duct air flow.)
4. Place a direct reading diffuser balancing hood over the face of
each Therma-Fuser diffuser and adjust damper at duct takeoff
to obtain maximum design air volume.
5. Return Therma-Fuser diffusers to operating condition.
a. Open appearance panel.
b. Attach tension spring to bracket (removed in step 2b).
c. Close appearance panel.
Fig. 3 Measuring blade opening
Foam
Blade
acutherm.com | THERMA-FUSER - Manual
Fig. 2 Remove spring to drop
blades open for balancing
Remove spring to drop blades open
Housing
Small Steel Rule
RECOM
VARIO
R
Te
Cooling
T
Mode
C
TF-C
T
TF-CW
W
TF-HC
Heating
T
Mode
C
TF-HC
T
W
Too
A
Noisy
TF-C
TF-CW
TF-HC
TF-D
3
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