P/N 558756_C
HUSSMANN CORPORATION • BRIDGETON, MO 63044-2483 U.S.A.
23
EcoVision EZ Door Upgrade
Condenser: The condenser will not typically
need to be replaced. However, if winter con-
trol is provided and there is a Total Heat of
Rejection (THR) load drop of greater than
40 percent, the winter control valve should be
checked.
Receiver Pressure Regulator: The sizing on
these series of valves will probably be accept-
able and a small reset on the A8/A9 series may
be required.
Solenoid Valves: Depending on the manufac-
turer and function of the solenoid valves, the
sizing may need to be looked at. Some mod-
els require a pressure drop across the valve in
order to close. If the flow through the valve
is too small, the pressure drop may not exist
and therefore the valve may not operate as
designed.
Sub-Cooler: If the rack is sub-cooled and the
drop in total BTU/HR is greater than 35 perc-
net, the sub-cooler and its TXVs may need to
be resized.
HEATING, VENTILATION, AIR-CONDITIONING
SYSTEM (HVAC)
In some instances, the HVAC system is sized
based on an assumption that a portion of the
refrigeration capacity will be used to reduce the
temperature and humidity in the store. This
is called “case credits.” This reduction in AC
load is calculated based on the “spillover” of
the chilled air from these cases by adding doors
this “spillover” is eliminated.
If these credits were taken, and doors are
applied to a major part of the refrigeration
load, typically 35 percent or more, the HVAC
system needs to be evaluated to see if it can
handle the entire air-conditioning load.
In addition to the adjustments above, the
following tasks must also be considered:
1. Time required to isolate that portion of the
system where the component(s) will be replaced;
2. Removal of the refrigerant (per government
guidelines);
3. Removal of the part(s) to be replaced;
4. Installing the new component(s);
5. Evacuation of that part of the system that
was isolated;
6. Recharging of the refrigerant that was
removed and;
7. Setting of each valve/component installed.
