BS 4856-2:1975

Co-operating organizations
Foreword
Methods
1 Scope
2 References
3 Definitions
4 Nomenclature
5 Objects of the tests
6 Limitations of accuracy of the test method
7 Testing conditions
8 Steady state conditions
9 Instrumentation
10 Test equipment
11 Air temperature measurements
12 Primary fluid measurements
13 Test facility
14 Thermal rating: results and analysis
15 Air volume flow rate measurements
16 Enclosure sweating tests and condensate disposal
    tests
17 Electrical rating test
18 Psychrometric test method
19 Air volume flow measurement for psychrometric test
    method
20 Rating tests (psychrometric test method)
21 Examples (psychrometric test method)
Tables
1 Steady state conditions
2 Enclosure swear test conditions
3 Sensible cooling test series
4 Sensible and latent colling test series
5 Calculation of sensible cooling duty at room
    temperature of 25 deg C
6 Results for example of sensible and latent cooling
Figures
1 Thermometer pockets
2 Multi-junction differential thermocouple
3 Inverted U-tube manometer
4 Shields for thermometer and thermocouple
5 Air sampling tubes
6 Air flow chamber
7 Chilled fluid test equipment
8 Piezometer ring
9 Extended air flow chamber
10 Room temperature measuring stations
11 Inlet temperature measurement
12 Water temperature correction factor KW
13 Determination of air flow rate
14 Example of recirculation correction factor
15 Heat transference
16 Rating example
17 Primary fluid plus metal thermal resistance

Coolers as used for cooling and dehumidifying under frost-free conditions, the medium used being water or other heat transfer fluid (excluding volatile refrigerants).

Part 2 of this British Standard deals with methods of carrying out thermal and volumetric tests of unit coolers without additional ducting. The unit coolers operate with or without condensation on the coils. The unit coolers are of the type used for cooling and dehumidifying purposes under frost-free conditions of operation. The cooling medium used is water or other heat transfer fluid (excluding volatile refrigerants). The range of approximate air volume flow rates is between 25 × 10^–3 m³/s and 5 m₃/s.

The tests are to be carried out on units in an essentially clean condition.

This standard applies to units having operating temperatures of primary fluid within the range 0 °C to 27 °C.

The primary fluids used are; water, brine, glycol, heat transfer fluid.

The minimum temperature differential (see 14.2) of the primary fluid under test is 3 °C.

There is no restriction on the mounting of these units for testing provided that they are tested whilst mounted in a way representative of their intended use.

The standard specifies performance characteristics that are to be obtained from a unit. Although the requirements of the methods for individual tests may be followed to determine the performance of a unit at one specified set of conditions, where the performance at conditions other than those of the actual test are to be stated the full schedule of tests specified in the standard have to be made.