USE OM
– JANUARY 2017
21
3.
Mixed Expansion Device Requirements
A.
Mixed systems may use an appropriately sized thermostatic expansion valve (TXV) except for
series restrictor systems described below.
B.
Flow Factor requirements on mixed coils with fixed restrictions:
If the Highest Sales Volume Tested Combination (HSVTC) matched system has a
fixed restrictor, then the mixed system flow factor shall be within the range of 100-
125%; unless the HSVTC matched system uses a series capillary tube restriction
arrangement (i.e. no check valves), then the flow factor for the mixed system shall
be within the range of 100-115%.
If the HSVTC system is a TXV system, but there are other matched systems which
use a fixed indoor restrictor, then the flow factor for the mixed system is based on
the fixed indoor restrictor with cooling capacity closest to the tested system. The
mixed flow factor shall be within the range of 100-125%.
C.
If the certified matched system combinations have only TXV indoor, then the mixed system
shall be TXV.
4.
The mixed Indoor Unit assembly shall meet the same burst strength requirements as the matched
Indoor Unit assembly.
5.
If a supplemental heater is operated simultaneously with the heat pump, the heater shall be located
in the indoor air circuit downstream from the indoor coil. The heater shall be capable of operating
reliably at elevated ambient conditions (30-40°F above return air temperatures).
6.
If the return air passes over the indoor coil before passing over the blower motor, the motor shall be
capable of operating reliably at elevated ambient conditions (30-40°F above return air temperatures).
Содержание OM 210
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Страница 37: ...USE OM JANUARY 2017 29 Figure C2 Use of Unqualified Outdoor Units for ICM Testing ...
Страница 50: ...USE OM JANUARY 2017 42 Figure G2 Part 2 of the ORNL Flowchart ...
Страница 55: ...USE OM JANUARY 2017 47 Figure K1 Nozzle Combination Tests 66 Figure K2 Passive Pressure Drop Device 75 ...