• Automatically responds to Varying Duct Pressures

• CVR Models for Standard, Low and High Pressure

Applications

The Nailor Constant Volume Regulator (CVR) is an extremely cost-effective way to precisely control

the airflow in HVAC systems – especially high-rise buildings (such as exhaust shafts) – without

the need for controls or sensors. The CVR is a pressure independent self-regulating damper which

adjusts to maintain a constant set airflow.

CONSTANT VOLUMEREGULATORS

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• Minimizes Building Stack Effect

• Conserves Energy

The Nailor Constant Volume Regulator (CVR) is an extremely cost-effective way to precisely control

CVR-SP, CVR-LP, CVR-HPThe CVR contains a blade and spring piston which self-adjust to maintain the preset constant airflow volume. They adjust automatically for variable duct pressures caused by building pressure, thermal stack effect, dust buildup and other variable adverse conditions. The CVR can be used in either supply or exhaust applications by simply placing the factory mounted collar-side against the airflow direction in all models offered.

Operational Static Pressure Ranges:CVR-SP Standard Pressure – 0.2" to 0.8" w.g. (50 to 200 Pa)CVR-LP Low Pressure – 0.08" to 0.4" w.g. (20 to 100 Pa)CVR-HP High Pressure – 0.6" to 2.4" w.g. (148 to 597 Pa)

CVR-FDThe CVR-FD is the Constant Volume Regulator assembled with a UL 555 Listed 1-1/2 hour static or dynamic curtain fire damper. This model is available for supply or exhaust applications. This labor saving model is complete, requires no rear retaining angles, and reduces installation time.

CVR-GMThe CVR-GM is the Constant Volume Regulator in a flanged box for grille mount purposes (factory supplied or by others). This model is available for supply or exhaust applications. Used in applications where fire dampers are not required, this model comes preassembled for quick and easy installation.

CVR-TThe CVR-T is the Constant Volume Regulator with a square or round transition collar on either side, allowing for any duct shape application. The CVR features a blade and spring piston which self-adjust to maintain the preset constant airflow volume.

CVR-FD

SIZE (NOMINAL)

C DEPTH

DDIA.

4" (102) 2.8" (70) 3.7" (94)5" (127) 3.4" (86) 4.625" (117)6" (152) 3.6" (91) 5.9" (150)8" (203) 3.6" (91) 7.7" (196)

10" (254) 5.0" (127) 9.625" (244)

SIZING:PERFORMANCE CURVESSTANDARD PRESSURE

* set point numbers on regulator are in m3/H

Sample of airflow setting: Set Point Mark 140 = 140 m3/H = 83 CFM

265 − 470 CFM900850800750700650600550500450

M�/h*530500470441412382353325295265

CFM SET POINT (CFM)800 (470)

750 (441)

700 (412)

650 (382)600 (358)550 (325)500 (295)450 (265)

"w.g. 0.2 0.4 0.6 0.8 1.0 PRESSURE DIFFERENCE

175 − 295 CFM600

550

500

450

400

350

300

250

M�/h*350

325

295

265

235

206

175

147

CFM SET POINT (CFM)500 (295)

450 (265)

400 (235)

350 (206)

300 (175)

"w.g. 0.2 0.4 0.6 0.8 1.0 PRESSURE DIFFERENCE

105 − 175 CFM350330310290270250230210190170

M�/h*206194182171160148136124112100

CFM SET POINT (CFM)300 (175)

270 (160)

240 (141)

210 (124)180 (105)

"w.g. 0.2 0.4 0.6 0.8 1.0 PRESSURE DIFFERENCE

60 − 105 CFM230

210

190

170

150

130

110

90

M�/h*135

124

112

100

88

77

65

53

CFM SET POINT (CFM)

180 (106)

150 (88)

120 (70)100 (60)

"w.g. 0.2 0.4 0.6 0.8 1.0 PRESSURE DIFFERENCE

30 − 60 CFM

120

100

80

60

40

M�/h*

70

60

47

35

24

CFM SET POINT (CFM)

100 (60)

90 (53)

75 (44)

60 (35)

50 (30)

"w.g. 0.2 0.4 0.6 0.8 1.0 PRESSURE DIFFERENCE

SIZE (NOMINAL) FLOW RATE RANGE (CFM)

4" (102) 30-60 − − − −

5" (127) 30-60 60-105 − − −

6" (152) 30-60 60-105 105-175 − −

8" (203) − 60-105 105-175 175-295 −

10" (254) − − 105-175 175-295 265-470

AIRFLOW:

When choosing a CVR model, select the appropriate size for your building needs. Then select the desired flow rate range among those available for your size.

For adjusting your CVR, reference our performance curve table and choose your maximum desired flow rate versus pressure. Choose a Set Point on the CVR that best matches that flow rate (see graphic for example). Using a Torx T-10 bit, loosen the adjustment screw. Re-tighten the screw when the self-adjusting aerowing lines up with desired Set Point.

THERMAL STACK EFFECT Without the use of a CVR there can be what is called "Stack Effect". Stack Effect is an imbalance of exhaust airflow from floor to floor due to varying pressure changes, creating an inefficient and imbalanced exhaust system throughout the building. This can create stale or uncomfortable settings and be costly. The CVR eliminates Stack Effect by automatically adjusting to these varying pressures, creating equalized airflow and exhaust among all floors.

WCVR 10.20

Each size is supplied with factory installed shims where necessary to achieve different airflow ranges. See the graphic for an example and the chart for a detailed total assembly.

Size (Nominal)

FLOW RATE (CFM)

TOTAL ASSEMBLY

4" (102) 30-60 4" (102) Regulator5" (127) 30-60 4" (102) Regulator + 1 Shim5" (127) 60-105 5" (127) Regulator6" (152) 30-60 4" (102) Regulator + 2 Shim6" (152) 60-105 5" (127) Regulator + 1 Shim6" (152) 105-175 6" (152) Regulator8" (203) 60-105 5" (127) Regulator + 2 Shims8" (203) 105-175 6" (152) Regulator + 1 Shim8" (203) 175-295 8" Regulator

10" (254) 105-175 6" (152) Regulator + 2 Shims10" (254) 175-295 8" Regulator + 1 Shim10" (254) 265-470 10 Regulator

-100-120-140-160-180

110-130-150-170-

-180-200-220-240-260-280-300

190-210-230-250-270-290-

-300-350-400-450-500

320-370-420-470-

8" 175-195 CFM(8" regulator)

8" 105-175 CFM(6" regulator + 1 Shim)

8" 60-105 CFM(5" regulator + 2 Shims)

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45 CFM

45 CFM

45 CFM

45 CFM

45 CFM

160 CFM

126 CFM

84 CFM

42 CFM

0 CFM

WITHOUT CVR WITH CVR