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WSV6 VERTICAL SERIES - IOM
WSV6 Vertical Series – IOM 27
APPLICATION CONTINUED
ECONOMIZER
OVERVIEW
In large commercial buildings, it is common for simultaneous heating and cooling loads to be required during the winter and
shoulder seasons. In order to balance the need for different heating and cooling loads, an economizer can be used to provide
“free” cooling to spaces that require it. The water-source heat pumps nearer to the exterior of the building will heat the space
by extracting heat from the building’s fluid supply. The chilled fluid supply can then be used to provide cooling, by passing the
fluid through the economizer coil.
FEATURES AND BENEFITS
The Hydrotech WSV6 waterside economizer option is a modular hydronic cooling coil that uses the buildings water loop to
provide “free” cooling to the space. The economizer works by sensing the entering fluid temperature into the water-source
heat pump and when the temperature falls below a specified set point, the system will turn off the compressor and divert the
incoming chilled fluid into the economizer coil.
The ASHRAE 90.1 Energy Standard for Buildings, requires that water-source heat pumps over 54,000 BTUh of capacity be
equipped with a water-side economizer. For the jurisdictions in which the ASHRAE 90.1 2019 standard is fully ratified, the
Hydrotech WSV6 waterside economizer option satisfies all ASHRAE 90.1 requirements for the inclusion of an economizer on
water-source heat pump units.
ECONOMIZER PERFORMANCE DATA
ECONOMIZER PERFORMANCE TABLE
Unit
Airflow
Flowrate
Pressure Drop
Coil Pressure Drop
SCFM
GPM
FOH
IWC
WSV6048
1200
6
1.5
0.18
1400
9
3.3
0.22
1600
12
5.7
0.28
WSV6060
1500
7.5
1.8
0.15
1750
11.3
3.8
0.19
2000
15
6.5
0.23
WSV6072
1200
9
2.5
0.21
1400
13.5
5.3
0.27
1600
18
9.2
0.32
NOTE: Pressure drop measured at 45° EWT
Table 7 – Economizer Performance Data
To ensure optimum performance of the economizer coil, it is recommended that the EWT temperature be between 40°F – 50°F.
Temperatures above 50°F will limit effectiveness of the economizer coil. The electronic temperature sensor has a default set point
value of 45°F.
The economizer coil adds a substantial amount of additional static pressure to the unit’s blower system. To ensure adequate
airflow refer to
TABLE 7 – Economizer Performance Data.