Greenheck Programming Sure-Aire K-Factor User Manual

Document 478758

Programming Sure-Aire™

Greenheck’s Sure-Aire™ Differential Pressure Controller provides either a 2-10 Vdc or 4-20 mA electrical output signal. The output signal is linearly proportional to the pressure range of differential pressure controller. The ranges for Greenheck’s Sure-Aire

Greenheck Part Number

100-240 VAC 24 VAC / VDC

384799 384986 0-8.30 8.30

384800 384987 0-22.14 22.14

384801 384988 0-41.52 41.52

384802 384989 0-83.04 83.04

384803 384990 0-138.40 138.40

Controller ∆P Range

(inches W.C.)

max

(inches W.C.)

controllers are listed in the table.

Calculating Flow from Differential Pressure

The volumetric ﬂow through the fan (cfm) can be calculated from the equation:

CFM = K

∆P



where K is the K-factor for the speciﬁc fan model and size, ∆P is the measured differential pressure across the inlet cone (inches W.C.), and  is the air density (lb/ft

). K-factors for Greenheck models are found on the back of

this document.

Calculating Flow from Voltage Signal

If using a 2-10 Vdc output signal from a differential pressure controller, this equation can be used to calculate the ﬂow:

CFM = K

(V - 2) P

where V is the output voltage of a 2-10 Vdc transmitter and P

max



is the maximum pressure range of the controller

max

being used (inches W.C.).

Calculating Flow from Current Signal

If using a 4-20 mA output signal from a differential pressure controller, this equation can be used to calculate the ﬂow:

CFM = K

(mA - 4) P

where mA is the output current of a 4-20 mA transmitter and P

max



is the maximum pressure range of the

max

controller being used (inches W.C.).

Density Corrections

Air density, , is affected by elevation and temperature. The Greenheck Sure-Aire Differential Pressure Controllers allow the user to input the elevation for the application. This elevation input automatically updates the density used for the ﬂow calculation.

The Remote Temperature Sensor will adjust the air density value in the controller based on the sensor measurement when Temperature Compensation is set to ‘Yes’. This density compensation will affect the ﬂow rate displayed on the controller. If Temperature Compensation is set to ‘No’, the air density value will be a function of standard air (70°F/21°C).

The density being used by the Sure-Aire controller can be viewed on the main menu by scrolling up or down through the settings.

Programming Sure-Aire™

K-Factors

CSW

Size

AFSW / BISW

VK- H / VK-CD

7 259 not applicable not applicable not applicable not applicable

8 252 not applicable not applicable not applicable not applicable

9 248 not applicable 408 not applicable not applicable

10 202 not applicable not applicable not applicable not applicable

12 296 592 408 355 not applicable

13 351 701 not applicable not applicable not applicable

15 431 861 603 355 526

16 531 1062 724 421 634

18 542 1083 897 517 787

20 650 1301 1088 617 955

22 805 1610 1321 759 1161

24 982 1964 1631 913 1436

27 1184 2369 1962 1105 1729

30 1464 2928 2400 1355 2116

33 1770 3540 2923 1625 2581

36 2168 4336 3576 1967 3154

40 2630 5259 4331 2361 3825

44 3220 6440 5318 2854 4698

49 3904 7808 6525 3411 5766

54 4785 9571 7891 4121 6975

60 5854 11707 9648 4972 not applicable

66 7083 14166 not applicable 5960 not applicable

73 8665 17330 not applicable 7276 not applicable

AFDW / BIDW QEI QEM / QEP / HPA VK-MD

Our Commitment

As a result of our commitment to continuous improvement, Greenheck reserves the right to change speciﬁcations without notice.

Speciﬁc Greenheck product warranties are located on greenheck.com within the product area tabs and in the Library under Warranties.

Greenheck’s Sure-Aire™ Flow Monitoring Systems catalogs provides additional information describing the equipment, fan performance, available accessories, and speciﬁcation data.

Phone: 715.359.6171 • Fax: 715.355.2399 • Parts: 800.355.5354 • E-mail: gfcinfo@greenheck.com • Website: www.greenheck.com

AMCA Publication 410-96, Safety Practices for Users and Installers of Industrial and Commercial Fans, provides additional safety information. This publication can be obtained from AMCA International, Inc. at www.amca.org.