Accurex XCR, Manual

Page: 44 / 64

Variable Volume – Variable volume or demand ventilation
offers significant energy savings by only exhausting
conditioned air when necessary throughout a day. This
type of application can greatly reduce the operating
costs associated with air conditioning and heating. Either
a Greenheck Vari-Green
®
motor or standard variable
frequency drive (VFD) compatible motor can function
within a variable volume system and help reduce
energy consumption.
Vari-Green Drive (VGD) – Greenheck's Vari-Green Drive is
a factory mounted, wired, and programmed variable
frequency drive. Specifically designed for use in air
handling applications, the Vari-Green drive expands
variable volume operation and simplistic speed adjustment to three-phase applications.
Variable Frequency Drive (VFD Rated) – For applications that require a higher horsepower. A VFD rated/compatible
motor will also allow the fan performance to be adjusted. Although a comparable VFD rated motor is not as efficient
as the Greenheck Vari-Green motor, it can still assist in system balancing and provide flexibility in adapting to
system changes. It can also help reduce energy consumption. The motors meet NEMA Premium efficiencies.
Note: VFD rated motors will need VFD controllers by others and will require start-up programming.
Greenheck Vari-Green System Controls – A controlled system reduces the energy consumed by decreasing the
speed of the fan and energy used by the motor. The system controls will lessen the amount of conditioned air that
is exhausted, further reducing the total operating costs. For more detailed information refer to the Greenheck
Vari-Green Motor brochure on accurex.com.
A 0-10 VDC control signal may be used in conjunction with:
• Greenheck Vari-Green system controls - for constant pressure
• Vari-Flow - controls based upon temperature
• CO2 Sensors - monitors carbon dioxide levels
• VOC Sensors - monitors a range of volatile organic compounds
• Motion Detectors - monitors occupancy
ROOF EXHAUST OPTIONS AND ACCESSORIES XRED
GREENHECK VARI-GREEN SYSTEM
CONTROLS FOR VARIABLE VOLUME - XRED
This system is designed for applications requiring
constant pressure control, variable volume or
demand-controlled ventilation as used in multi-
storied buildings such as hotels, multi-family
complexes, institutional facilities, and high rise
commercial buildings. The system utilizes XRED
fans with a Greenheck Vari-Green motor,
controller, pressure tap, and pressure transducer.
It is preprogrammed and easy to install. Applications
include, venting dryers, bathrooms, residential type
kitchen space or industrial process exhaust.
VARIABLE VOLUME VS. CONSTANT VOLUME
Example of
potential saving
based on a
northeast city in
the USA using
a Greenheck
Vari-Green
System.
$2,000
Heating Cost
($/year)
Cooling Cost
($/year)
Fan Operating
Cost
1,750
1,500
1,250
1,000
750
500
250
$
Variable Volume Constant Volume
HYPOTHETICAL VARIABLE VOLUME - LOAD SHAPE
% OF OPE
RA
TION
100
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
80
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
60
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
40
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
20
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
0%
$ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $ $
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
TIME OF DAY
CONSTANT VOLUME – LOAD SHAPE
% OF OPE
RA
TION
100
80
60
40
20
0%
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24
TIME OF DAY