EN 12975-2:2006

Foreword
Introduction
1 Scope
2 Normative references
3 Terms and definitions
4 Symbols and units
5 Reliability testing of liquid heating collectors
  5.1 General
  5.2 Internal pressure tests for absorbers
       5.2.1 Inorganic absorbers
       5.2.2 Absorbers made of organic materials
              (plastics or elastomers)
  5.3 High-temperature resistance test
       5.3.1 Objective
       5.3.2 Apparatus and procedure
       5.3.3 Test conditions
       5.3.4 Results
  5.4 Exposure test
       5.4.1 Objective
       5.4.2 Apparatus and procedure
       5.4.3 Test conditions
       5.4.4 Results
  5.5 External thermal shock test
       5.5.1 Objective
       5.5.2 Apparatus and procedure
       5.5.3 Test conditions
       5.5.4 Results
  5.6 Internal thermal shock test
       5.6.1 Objective
       5.6.2 Apparatus and procedure
       5.6.3 Test conditions
       5.6.4 Results
  5.7 Rain penetration test
       5.7.1 Objective
       5.7.2 Apparatus and procedure
       5.7.3 Test conditions
       5.7.4 Results
  5.8 Freeze resistance test
       5.8.1 Objective
       5.8.2 Apparatus and procedure
       5.8.3 Test conditions
       5.8.4 Results
  5.9 Mechanical load test
       5.9.1 Positive pressure test of the collector
       5.9.2 Negative pressure test of the collector
  5.10 Impact resistance test (optional)
       5.10.1 Objective
       5.10.2 Apparatus and procedure
       5.10.3 Test conditions
       5.10.4 Results
  5.11 Final inspection
  5.12 Test report
6 Thermal performance testing of liquid heating collectors
  6.1 Glazed solar collectors under steady state conditions
       (including pressure drop)
       6.1.1 Collector mounting and location
       6.1.2 Instrumentation
       6.1.3 Test installation
       6.1.4 Outdoor steady-state performance test
       6.1.5 Steady-state efficiency test using a solar
              irradiance simulator
       6.1.6 Determination of the effective thermal capacity
              and the time constant of a collector
       6.1.7 Collector incidence angle modifier
       6.1.8 Determination of the pressure drop across a collector
  6.2 Unglazed solar collectors under steady state conditions
       (including pressure drop)
       6.2.1 Collector mounting and location
       6.2.2 Instrumentation
       6.2.3 Test installation
       6.2.4 Outdoor steady state efficiency test
       6.2.5 Steady-state efficiency test using a solar irradiance
              simulator
       6.2.6 Determination of the effective thermal capacity
              and the time constant of a collector
       6.2.7 Incidence angle modifier (optional)
       6.2.8 Determination of the pressure drop across a collector
  6.3 Glazed and unglazed solar collectors under
       quasi-dynamic conditions
       6.3.1 Collector mounting and location
       6.3.2 Instrumentation
       6.3.3 Test installation
       6.3.4 Outdoor efficiency test
       6.3.5 Determination of the effective thermal capacity
       6.3.6 Collector incidence angle modifier
Annex A (normative) Schematics for durability and
                    reliability tests
Annex B (normative) Durability and reliability test report
                    sheets
      B.1 Record of test sequence and summary of main
           results
      B.2 Internal pressure test for inorganic absorbers
           B.2.1 Technical details of collector
           B.2.2 Test conditions
           B.2.3 Test results
      B.3 Internal pressure test for absorbers made of organic
           materials
           B.3.1 Technical details of collector
           B.3.2 Test conditions
           B.3.3 Test results
      B.4 High-temperature resistance test
           B.4.1 Method used to heat collectors
           B.4.2 Test conditions
           B.4.3 Test results
      B.5 Exposure test
           B.5.1 Test conditions
           B.5.2 Test results
           B.5.3 Climatic conditions for all days during the test
           B.5.4 Time periods in which irradiance and surrounding
                 air temperature have values greater than those
                 specified in Table 4
           B.5.5 Inspection results
      B.6 External thermal shock test:
           B.6.1 Test conditions
           B.6.2 Test results
      B.7 Internal thermal shock test:
           B.7.1 Test conditions
           B.7.2 Test results
      B.8 Rain penetration test
           B.8.1 Test conditions
           B.8.2 Test results
      B.9 Freeze resistance test
           B.9.1 Collector type
           B.9.2 Test conditions
           B.9.3 Test results
      B.10 Mechanical load test
           B.10.1 Positive pressure test of the collector cover
           B.10.2 Negative pressure test of fixings between the
                  cover and the collector box
           B.10.3 Negative pressure test of collector mountings
      B.11 Impact resistance test using steel balls
           B.11.1 Test conditions
           B.11.2 Test procedure
           B.11.3 Test results
      B.12 Impact resistance test using ice balls
           B.12.1 Test conditions
           B.12.2 Test procedure
           B.12.3 Test results
      B.13 Final inspection results
Annex C (normative) Stagnation temperature of liquid
                    heating collectors
      C.1 General
      C.2 Determination of stagnation temperature
Annex D (normative) Performance test report for glazed
                    solar collectors
      D.1 General
      D.2 Solar collector description
      D.3 Test results
Annex E (normative) Performance test report for unglazed
                    solar collectors
      E.1 General
      E.2 Solar collector description
      E.3 Test results
Annex F (normative) Modelling of the coefficients c[1] to c[6]
                    of the collector model of 6.3
Annex G (normative) Measurement of effective thermal
                    capacity
      G.1 Test installation
      G.2 Indoor test procedure
          G.2.1 General
          G.2.2 Measurements
          G.2.3 Calculation of the effective thermal capacity
          G.2.4 Determination of effective thermal capacity from
                experimental data
      G.3 Outdoor or solar irradiance simulator test procedure
Annex H (informative) Comparison of the collector model
                      of 6.1 to the collector model of 6.3
Annex I (informative) Properties of water
      I.1 Density of water (at 1 bar) in kg/m[3]
      I.2 Specific heat capacity of water (at 1 bar) in kJ/(kg K)
Annex J (informative) Performance test report summary for
                      quasi dynamic test method
Annex K (informative) General guidelines for the assessment
                      of uncertainty in solar collector efficiency
                      testing
      K.1 Introduction
      K.2 Measurement uncertainties in solar collector
          efficiency testing
Annex L (informative) Determination of the pressure drop
                      across a collector
      L.1 General
      L.2 Test installation
      L.3 Preconditioning of the collector
      L.4 Test procedure
      L.5 Measurements
      L.6 Pressure drop caused by fittings
      L.7 Test conditions
      L.8 Calculation and presentation of results
Bibliography

This European Standard specifies test methods for validating the durability, reliability and safety requirements for liquid heating collectors as specified in EN 12975-1. This standard also includes three test methods for the thermal performance characterisation for liquid heating collectors.It is not applicable to those collectors in which the thermal storage unit is an integral part of the collector to such an extent that the collection process cannot be separated from the storage process for the purpose of making measurements of these two processes.It is basically applicable to tracking concentrating collectors, thermal performance testing as given in 6.3 (quasi dynamic testing) is also applicable to most concentrating collector designs, from stationary non-imaging concentrators as CPCs to high concentrating tracking designs. Parts of the solar radiation measurement should be adjusted in case of a tracking collector and in case a pyrheliometer is used to measure beam radiation.Collectors that are custom built (built in; e.g. roof integrated collectors that do not compose of factory made modules and are assembled directly on the place of installation) cannot be tested in their actual form for durability, reliability and thermal performance according to this standard. Instead, a module with the same structure as the ready collector may be tested. The module gross area should be at least 2 m2. The test is valid only for larger collectors than the tested module.