NEN EN 308 : 1997

Introduction
1 Scope
2 Normative references
3 Symbols and subscripts
4 Definitions
    4.1 Heat recovery device
    4.2 Mass flows
    4.3 Ratios
    4.4 External leakage
    4.5 Internal leakage
    4.6 Internal exhaust air leakage
    4.7 Carry-over air flow
    4.8 Reference conditions
    4.9 Pressure
5 General requirements
    5.1 Heat recovery device
    5.2 External leakage
    5.3 Internal exhaust air leakage
    5.4 Carry-over
    5.5 Temperature and humidity ratios
    5.6 Pressure drop
6 Test procedures and accuracy requirements
    6.1 External leakage test
    6.2 Internal exhaust leakage test (categories 1 and IIa)
    6.3 Carry-over test (category III)
    6.4 Ratio tests (see figure 3)
    6.5 Pressure drop tests (see figure 3)
    6.6 Heat balance
7 Test report
    7.1 Heat recovery device
    7.2 External leakage
    7.3 Internal exhaust air leakage
    7.4 Carry-over
    7.5 Temperature and humidity ratios
    7.6 Pressure drop: for standard air
    7.7 Other indications

Defines methods for use in laboratory testing of air-to-air heat recovery devices or those recovering heat from flue gases of heating appliances in buildings (not including process-process applications) for obtaining of rating data. Provides test requirements and methods for performance of such tests and defines input criteria necessary for tests for verification of performance data supplied by the manufacturer.