Price Acutherm TLW-C Instructions for use

FORM 23.2 REV 1704
THERMA-FUSER
™
THERMALLY POWERED VAV DIFFUSER
INSTALLATION, BALANCING & MAINTENANCE
MODULAR VAV SYSTEMS
SIDEWALL MODELS:
TLW-C VAV cooling only
TLW-CW VAV cooling and warm up (constant
  volume heating)
 TLW-D Manually adjustable diffuser
 TLW-RAD Return-ducted
 TLW-RAP Return-ceiling plenum
TABLE OF CONTENTS
Installation Instructions . . . . . . . . . . . . . . . . . . 1
System Balancing . . . . . . . . . . . . . . . . . . . . . . . . 2
Adjusting Temperature Setpoint . . . . . . . . . . .  3
Maintenance . . . . . . . . . . . . . . . . . . . . . . . . . . . .  3
Controlling the System . . . . . . . . . . . . . . . . . . . 3
Fire Walls . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3
Dimenisions . . . . . . . . . . . . . . . . . . . . . . . . . . . . 4
Minimum Flow . . . . . . . . . . . . . . . . . . . . . . . . . 5
Model Designation . . . . . . . . . . . . . . . . . . . . . . 5
Trouble Shooting . . . . . . . . . . . . . . . . . . . . . . . . 5
Ten Year Warranty. . . . . . . . . . . . . . . . . . . . . . .  6
Continued on NEXT Page
One or Round Top 53/4in. / 146 mm
Two Slots Rear Rectangular 45/8in. / 118 mm
 Four Slots Round Top 73/4in. / 197 mm
  Rear Rectangular 65/8in. / 169 mm
 MODEL TYPE INLET MIN. OPENING HEIGHT
Table 1. Minimum opening height to slide diffuser in
DAMAGED FREIGHT CLAIM PROCEDURE
When the diffusers are received, inspect for damage which may
have occured during shipment. If damage is evident, it should be
noted on the carrier's freight bill. A written request for inspection
by the carrier's agent should be made at once.
STORAGE
Cartons should always be stacked on end. Do not stack cartons
flat on their sides. Excessive weight may cause damage to the
diffusers.
Do not store for prolonged times at temperatures exceeding
130°F/56°C.
IDENTIFICATION
Units are factory shipped two per carton. The model designation is
on the unit and on the carton. See Model Designation on page 5.
INSTALLATION PRECAUTIONS
When installing units, make sure construction debris does not
enter units or duct system.
Because models TLW-C and TLW-CW control room temperature
by sensing the room air induced up the wall of the room, care
should be taken not to disturb room air induction and entrain-
ment. Avoid the possibility of anything, including furniture, below
the diffuser which will block secondary air from entering the
induction chamber. Of special concern are tall bookcases. See
Fig. 2.
Fig 2. Do not block secondary room air
INSTALLATION INSTRUCTIONS
1. Inspect the carton for damage before opening. Notify carrier if
external damage exists. Submit all claims for shipping dam-
age to the carrier.
2. Move diffusers (in cartons) to installation area. Note unit
identification.
3. Remove cardboard box and cardboard insert. Discard pack-
aging material. Model TLW-C and TLW-CW have factory
installed balancing stops which hold the blade(s) open. See
Fig. 6. Do not remove those stops until after balancing.
4. Install ceiling, soffit and wall framework. Metal studs should
be located horizontally both above and below the opening for
the diffusers. See Figs. 3 and 4. If the diffuser is to be installed
by sliding it into the opening, allow a minimum vertical space
between the studs shown in the Table 1. Do not hang the
gypsum board before installing the diffuser.
5. Install the diffuser. Either lay the diffuser on the soffit frame-
work, See Fig. 4, or hang it from wires, See Fig. 5.
a. Do not block the induction nozzle on the control panel end
of the diffuser. Note: The installation must have provision
to vent the induction air either to the return air plenum or
to the room.
b. Do not use screws or drill holes in the areas marked “No
Holes or Screws” on the control panel end of the diffuser.
c. Do not install standard model TLW-C and TLW-CW linear
Therma-Fuser units end-to-end. A 2 in./51mm clear space
is required beyond the induction air outlet.
6. Connect and secure the supply duct to the inlet. Flexible duct
should be installed as straight as possible and should NOT be
formed in a centerline radius of less than 1½ times the duct
diameter. Improper installation may result in performance to
vary from published ratings.
OK
WALL
NO
WALL
?
DIFFUSER
Fig 3. Installing ceiling, soffit and wall framework
CEILING
WALL
HORIZONTAL METAL
STUDS SUPPORTED
BY WALL AND SOFFIT
FRAME WORK
GYPSUM
BOARD
HUNG AFTER
DIFFUSER
IS INSTALLED

Page 2
Continued on NEXT Page
 Type Ak Type Ak Type Ak
TLW-2411 .07 TLW-2421 .12 TLW-2441 .31
TLW-3611 .11 TLW-3621 .20 TLW-3641 .42
TLW-4811 .14 TLW-4821 .28 TLW-4841 .60
TLW-6011 .22 TLW-6021 .32 TLW-6041 .70
Table 2.  Akfactors in ft.² for TLW Therma-Fuser diffusers
fully open.
Fig 6. Balancing Stops
Balancing Stops
Figure 5. Holes for hanging
FOR HANGING, USE
TWO DIAGONAL
.110 IN. / 270 MM
HOLES IN THE
TOP OF THE
DIFFUSER
INSTALLATION INSTRUCTIONS—Continued
WALL
CEILING
MINIMUM
OPENING HEIGHT
TO SLIDE
DIFFUSER IN.
SEE TABLE 1.
CAN BE FIRE WALL
WALL STUD
Figure 4. Laying on soffit framing
7. Hang the gypsum board. The gypsum board should extend
behind all four sides of the diffuser face by 3/8 in./9.5mm.
See Fig. 4.
8. Do NOT reset the temperature set point on the TLW-C and
TLW-CW models until the space is occupied. It is factory pre-
set for average conditions (74°F / 23°C).
9. Balance the system. See System Balancing.
10. After the air conditioning system is started and after the
space is occupied, where necessary adjust the temperature
setpoint to suit the occupant. See Adjusting Temperature Set-
point.
SYSTEM BALANCING
(TLW-C and TLW-CW)
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 maxi-
mum air flow by fully opening them, the system is really a con-
stant air volume system and is balanced as a constant volume
system. Manual balancing dampers should be used at the take off
for each diffuser. Manual balancing dampers may not be required
with ducts designed to Acutherm specifications. Contact Acu-
therm for duct specifications and alternate balancing procedure
when no manual balancing dampers are used.
1. Prepare the system for balancing. (Make necessary checks for
diversity, fan capacities, fan rotation, miminum outside air
requirements, duct leaks and static pressure controller design
settings. Set outside air control damper for minimum air and
return air control damper for maximum air.)
2. Make sure Therma-Fuser diffusers are open. TLW-C and TLW-
CW models are shipped with balancing stops in position to hold
the blade(s) wide open. The stops are a wedge which should be
wedged between the foam side of the blade and the curved alu-
minum piece below it (pushing the blade so that its back is in
contact with the horizontal aluminum piece above it). See Fig.
6. For multiple blade units, all blades must be wedged open for
proper balancing.
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. Measure air flow from each Therma-Fuser diffuser and adjust
damper at the duct takeoff to obtain design air volume. Air
volume measurement may be made with a direct reading bal-
ancing hood or air velocity meter. If a velocity meter is used,
the velocity is measured in the lower slot 2 in. / 51mm from
either end of the blade at the opening between the outside
blades and the curved aluminum piece. See Fig. 7. The Ak
factors for the different linear lengths are shown in Table 2.
Multiply the velocity in fpm times Akin ft2to get air flow in
cfm.
5. Return Therma-Fuser diffusers to operating condition. Remove
balancing stops by grabbing the looped end and pulling
straight out from the face.
6. Return the remainder of the system to operating condition.
Figure 7. Location of Velometer
Measure in the lower
slot 2 In. / 51mm from
either end of the blade.
Probe
Velometer
1250 to
2300 fpm

Page 3
Continued on NEXT Page
CONTROLLING THE SYSTEM
(TLW-C and TLW-CW)
References:
• System Design, p 4, TLW brochure, Form 23.1.
• Chapters 2.2, 3.1 and 3.2, pp 6, 7 and 8, Designing Modular
VAV Systems, Form 5.2.
• Air Handling and Fan Coil Units Subzoned with Therma-Fuser
VAV modules, Form 6.7.
• DX Equipment Zoned with Therma-Fuser VAV Modules, Form
6.5.
SUPPLY AIR TEMPERATURE
The source of cooling is controlled from supply air temperature.
As with all VAV systems, the goals are to achieve a constant sup-
ply air temperature (may be reset to another constant supply air
temperature) and to limit the supply air temperature. Limits for
cooling supply air temperature should be between 50°F/10°C and
68°F/20°C. These objectives are best achieved by modulating
chilled water valves, and other variable equipment from supply air
temperature. On/off equipment such as DX compressors are
cycled from supply air temperature. Use a discharge air sensor
for the supply air temperature signal.
For TLW-CW models, mode change between heating,
recirculation and cooling is controlled from room temperature.
Signals from one or more room temperature sensors may be used
for mode change. When using more than one sensor, a “majority
rules” approach is recommended. Constant volume heating
temperature for TL-CW models should be as low as possible but
no lower than 80°F / 26.5° C.
STATIC PRESSURE
As with all VAV systems, the fan must run continuously during
occupied times. Goals of static pressure control are to provide
enough static pressure to obtain the required air volume
especially at the diffuser farthest from the fan, to avoid diffuser
noise by limiting static pressure at both full flow and turndown
and to provide pressure independence or consistent operation as
the system flow changes.
These objectives can be achieved with the usual methods of
automatic static pressure control: bypass dampers, discharge
dampers, zone dampers, and fan control (variable speed drives,
inlet dampers, etc.). Locate the static pressure sensor as far down
the duct as possible—at least 2/3 down the duct from the first
takeoff.
FIRE WALLS
For soffit installations, the fire wall can be extended up behind the
diffuser. See Fig. 3.
For installations with the diffuser face flush with the wall, the fire
wall should be extended beneath the diffuser and then up behind
it. See Fig. 9.
A fire damper should be installed in the supply air duct where it
penetrates the fire wall.
MAINTENANCE
The moving parts of the TLW Therma-Fuser diffuser have no
maintenance or lubrication requirements. We are often asked to
recommend periodic maintenance procedures and a spare parts
stock. Recommended maintenance is to clean the outer surfaces
of the Therma-Fuser diffuser—nothing else. We do not recom-
mend stocking any spare parts. Our customers also confirm that
stocking is unnecessary.
ADJUSTING TEMPERATURE
SETPOINT (TLW-C and TLW-CW)
The room temperature set point is adjusted by turning the phil-
lips screw with a phillips screwdriver to move the thermostat in
or out. Four slot units have two thermostats, each controlling two
slots, which are separately adjusted. The temperature scale,
located behind the thermostat slide, can be viewed at the end of
the diffuser slot. Each graduation on the temperature scale is
1°F/.55°C providing an easy way of determining the amount of
adjustment. Turning the phillips screw clockwise will move the
slide out over the temperature scale for a cooler set point. Turn-
ing the phillips screw counterclockwise moves the thermostat
slide in to a warmer setpoint. About 1½ turns will change the set-
point by 1°F/.55°C.
The diffuser is factory set to maintain approximately 74°F/23°C.
It is not necessary to adjust the temperature set point at time of
installation. Instead, make any adjustments after the system has
been started and the space is occupied. Then adjust only those
Therma-Fuser difusers where occupants are uncomfortable at
the factory set point.
Readjust to the factory set point by turning the phillips screw
clockwise (cooler set point) until the thermostat slide hits the
stop. Then turn counter clockwise (warmer) for nine turns.
Figure 8. Adjusting Temperature
Read the temperature set point at the bottom of the thermostat slide.
C
O
O
L
E
R
W
A
R
M
E
R
Warmer
Cooler
W
C
78°F/25°C
74°F/23°C
70°F/21°C
Thermostat
Slide
Temperature
Scale
Recommended
Action
Adjust for higher room temperature set point.
Therma-Fuser diffuser is correct. Check if cooling
is still required, and if not, turn cooling unit off.
Therma-Fuser diffuser is correct. Check for lack of
air or for too warm air temperature.
Adjust for lower room temperature set point.
Reduce static pressure. Recommended static
pressure is .05 to .25 in. wg / 12 to 62 Pa at the
inlet of the diffuser.
Blade
Position
Open
Closed
Open
Closed
Any
Room
Temp.
Too
Cold

Too
Warm

Any
Mode
Cooling


TLW-C
TLW-CW
Too
Noisy
RECOMMENDED ADJUSTMENTS FOR
VARIOUS CONDITIONS
Figure 9. Fire Wall Around Diffuser
FIRE WALL

Page 4
Continued on NEXT Page
Fig 1. Dimensions–install as close to ceiling as possible
MODELS TLW-C, TLW-CW,
TLW-D and TLW-RAD WITH
TOP ROUND INLET (PREFERRED)
13½"
343 mm 13"
330 mm
½"
13 mm
ACTUAL LENGTH 3/8"
9.5 mm TYP.
BOTH ENDS
Inlet
Diam.
A
TOP VIEW
15/8" / 41 mm
BC
1/2"
13 mm TYP.
BOTH ENDS
115/16" / 49 mm
TYP.
SOFFIT
OR WALL
CEILING
TEMPERATURE
ADJUSTMENT
SCREW
FRONT VIEWSIDE VIEW
Keep 2"/50mm clearance
for induction discharge
MODELS TLW-C, TLW-CW,
TLW-D and TLW-RAD WITH
OPTIONAL REAR RECTANGULAR INLET
13½"
343 mm
14"
356 mm 13"
330 mm
½"
13 mm
ACTUAL LENGTH 3/8"
9.5 mm TYP.
BOTH ENDS
TOP VIEW
C
1/2"
13 mm TYP.
TOP AND
BOTTOM
115/16" / 49 mm
SOFFIT
OR WALL
CEILING
TEMPERATURE
ADJUSTMENT
SCREW
FRONT VIEWSIDE VIEW
Keep 2"/50mm clearance
for induction discharge E
D
F
GB
FOUR SLOT
Nominal Actual Round Optional A B C D E F G
 Length Length Diameter Rectangular Inlet    
24 233/4in. 77/8in. 6 x 10 in. 161/16 in. 6in. 6in. 213/4in. 113/4in. 10 in. 65/8in.
(2441) 603mm 200mm 152 x 254mm 408mm 152mm 152mm 552mm 298mm 254mm 168mm
36 353/4in. 77/8in. 6 x 10 in. 221/16 in. 6in. 6in. 267/8in. 167/8in. 10 in. 65/8in.
(2641) 908mm 200mm 152 x 254mm 560mm 152mm 152mm 683mm 429mm 254mm 168mm
48 473/4in. 97/8in. 6 x 18 in. 291/16 in. 6in. 6in. 387/8in. 207/8in. 18 in. 65/8in.
(4841) 1213mm 250mm 152 x 457nn 738mm 152mm 152mm 987mm 530mm 457mm 168mm
60 593/4in. 117/8in.† 6 x 18 in. 377/16 in. 6in. 6in. 387/8in. 207/8in. 18 in. 65/8in.
(6041) 1518mm 300mm† 152 x 457mm 926mm 152mm 152mm 987mm 530mm 457mm 168mm
† Oval shaped inlet
Note: Dimensions
 inches ± 1/16
 millimeters ± 1.6 mm
ONE AND TWO SLOT
Nominal Actual Round Optional A B C  D E F G
 Length Length Diameter Rectangular Inlet   1 Slot2 Slot   
24 233/4in. 57/8in. 4 x 8 in. 151/16 in. 4 in. 29/16 in. 33/4in. 193/4in. 113/4in. 8 in. 45/8in.
(2411, 603mm 150mm 102 x 204mm 383mm 102mm 65mm 95mm 502mm 298mm 203mm 118mm
2421)
36 353/4in. 57/8in. 4 x 8 in. 211/16 in. 4 in. 29/16 in. 33/4in. 267/8in. 187/8in. 8 in. 45/8in.
(3611, 908mm 150mm 102 x 203 mm 535mm 102mm 65mm 95mm 683mm 479mm 203mm 118mm
(3621)
48 473/4in. 77/8in. 4 x 16 in. 281/16 in. 4 in. 29/16 in. 33/4in. 367/8in. 207/8in. 16 in. 45/8in.
(4811, 1213mm 200mm 102 x 406mm 713mm 102mm 65mm 95mm 937mm 530mm 406mm 118mm
4821)
60 593/4in. 77/8in. 4 x 16 in. 341/16 in. 4 in. 29/16 in. 33/4in. 367/8in. 207/8in. 16 in. 45/8in.
(6011, 1518mm 200mm 102 x 406 mm 865mm 102mm 65mm 95mm 937mm 530mm 406mm 118mm
6021)
Inlet
Diam.

Page 5
Minimum Flow as a % of Maximum Flow
Length
Designation 20% 30%
24 5 in. / 128 mm 10 in. / 254 mm
 36 8 in. / 204 mm 11 in. / 280 mm
 48 11 in. / 280 mm 16 in. / 407 mm
 60 14 in. / 356 mm 28 in. / 712 mm
Amount of Gasket to be Removed from each Blade
TROUBLE SHOOTING
(TLW-C and TLW-CW)
Trouble shooting Therma-Fuser diffusers requires looking at the
system as a whole. Before examining the Therma-Fuser diffuser
for failure it is worth the time to be sure the system is functioning
properly and that something has not been overlooked. Before
calling Acutherm, please complete the data log for all Therma-
Fuser diffusers to be evaluated.
SYSTEM CHECK LIST
The system should be:
1. Delivering 50°- 68°F/10° - 20°C supply air when in the  
 cooling mode.
2. Delivering 80°-120°F/26.5° – 49°C supply air when in the  
 heating mode. (TLW-CW only)
3. Maintaining static pressure at the inlet to each Therma- 
 Fuser diffuser between .05 and .25"wg/12 and 62 Pa.
THERMA-FUSER DIFFUSER CHECK LIST
Once the above checks have been completed, examine and
record the following (conditions may vary over time; several
measurements at different times may be required):
1. Room temperature 4 ft / 1.2 m above the floor directly  
 under the Therma-Fuser diffuser.
2. Supply air temperature at the inlet of the Therma-Fuser  
 diffuser.
3.  Static pressure at the inlet of the Therma-Fuser diffuser.
4. Cooling setpoint(s). See Fig 8. Read the cooling setpoint(s) 
 by counting the lines from the bottom of the scale to the  
 bottom of the slider.
5. Blade opening(s). Look into the diffuser slot and observe the 
 blade position. Is it fully closed, fully open or part way  
 between? Is the gasket installed on the full length of each  
 blade?
6. If possible, measure air flow with a flow hood or measure air 
 velocity as shown in Fig 7.
7. Is there anything below the diffuser which blocks secondary 
 air from the induction chamber?
8. Are the ends of the diffusers at least 2 in. / 50 mm apart?
9. Is construction or other debris clogging the perforated  
 plate in the inlet?.
TROUBLE SHOOTING DATA LOG
Set
Point(s)
Blade
Opening
Duct
S.P.
S.A.
Temp
Room
Temp
TimeDateLocation Type Diffuser Air
Flow
Length No. Slots
Continued on NEXT Page
TLW-CW-4821-I
MODEL DESIGNATION
Therma-Fuser—Linear
TL = Ceiling Lay in*
TLC = Ceiling Continuous*
TLW = Sidewall
Type-C = VAV cooling only
CW = VAV cooling plus warm-up (fully
opens for constant volume heating with
supply air temperature above 80°F/26.5°C)
D = Manually adjustable diffuser
RAD = Ducted return air
RAP = Ceiling plenum return air
Nominal Length—24, 36, 48 or 60 inches. 72
inches available for type RAP only.
Number of slots—1, 2 or 4
Blow direction—1 way
Factory installed options
I = Internal insulation
R = Rectangular inlet
A1 = Heater for remote adjust 1 and 2 slots
A2 = Heater for remote adjust 4 slot only.
* See separate dimensions and separate instructions for models TL-XX and
TLC-XX.
MINIMUM FLOW (TLW-C and TLW-CW)
Standard TLW units have a 10% leakage. To obtain higher mini-
mum flows, a shorter length of blade gasket (foam) for each
blade can be factory installed or it can be field removed per the
table below. The blade gasket must be removed at the end oppo-
site from the induction slot.
Fig 1. Dimensions–continued
MODEL TL-RAP
ACTUAL LENGTH
TOP
VIEW
C
1/2"
13 mm TYP.
TOP AND BOTTOM
115/16"
49 mm
TYP
33/4"
95 mm
13/4"
45 mm
FRONT
VIEW
SIDE
VIEW B
3/8"
9.5 mm TYP
BOTH ENDS