Thermal Storage; Variable Primary Flow; Connection Types And Sizes; Evaporator Connections - York YVAA Installation, Operation & Maintenance Instructions Manual

FORM 201.28-NM1.1
ISSUE DATE: 1/31/2018

THERMAL STORAGE

Thermal storage is the practice of storing cooling
energy during a period of little or no load and/or low
energy costs for use during periods of high load and/
or energy costs. Conventional cooling systems pro-
duce cooling when it is needed which is commonly
during times of peak demand. Thermal storage allows
generation of cooling capacity to occur during off-
peak periods and store that capacity to meet future
cooling requirements. Using thermal storage can result
in smaller equipment sizes, thereby reducing capital
cost, and also can result in significant energy cost sav-
ings.
The YVAA has special control logic to be able to pro-
duce chilled leaving brine temperatures below 4.4°C
(40°F) so as to supply a storage tank with chilled liquid
during times of low demand. YVAA chillers selected
for thermal storage operation can also be selected to ef-
ficiently provide chilled fluid at nominal cooling loads.

VARIABLE PRIMARY FLOW

Johnson Controls recommends a maximum 10% per min-
ute flow rate of change, based on design flow, for vari-
able primary flow applications. Provide 8 to 10 gallons
per chiller ton (8.6 to 10.8 liter per cooling KW) system
water volume. Insufficient system volume and rapid flow
changes can cause control problems or can even cause
chiller shutdowns. There are many other design issues
to evaluate with variable primary flow systems. Consult
your Johnson Controls Sales Office for more information
about successfully applying YVAA chillers.
JOHNSON CONTROLS

CONNECTION TYPES AND SIZES

For connection sizes relevant to individual models see
SECTION 5 - TECHNICAL DATA.

EVAPORATOR CONNECTIONS

Standard chilled liquid connections on evaporators
are of the Victaulic Groove type for ASME and PED
marked units and Flange type for GB marked units (see
Figure 12 on page 45 for flange dimensions on GB
marked vessels).

FIGURE 11 - VICTAULIC GROOVE

SECTION 4 - INSTALLATION
LD10494
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