The following table lists the parameters of the European collectors in accordance with EN 12975.

Depending on the chosen norm in the catalog column “Testing standard Solar Keymark” of the original EN 12975 catalog entry, a conversion factor needs to be multiplied to the old EN 12975 parameters:

• If the Solar Keymark standard column is empty or is set to “EN 12975” \(f_{Area}=\frac{A_{aperture}}{A_{gross}} \)
• If the Solar Keymark standard column is set to “EN ISO 9806:2013” or “EN ISO 9806:2017”
• \(f_{Area}=1 \)

The following calculations are used to convert the old collector data for ISO 9806:

1. Efficiency \(\eta_{0,b}\)
   a. For flat-plate and vacuum tube collectors with \(K_{d,0}\) as diffuser IAM factor = 0,95 \(\eta_{0,b} = \frac{\eta_{0,t}\cdot f_{Area}}{0.85+0.15K_{d,0}}\)
   b. For unglazed collectors \(\eta_{0,b} = {\eta_{0,t} \cdot} f_{Area} \cdot {(1- 3b_{u})}\)
   c. For concentrating collectors with the Reynolds number \(Re_{0}\) = 5000 \(eta_{0,b} = 2\cdot f_{Area}\cdot( \eta_{0,l} – \eta_{0,t}) + 3(\eta_{0,t}-\eta_{0,l})(1- \frac{1}{1+\frac{Re_{0}}{2000}})\)
2. Heat loss coefficient \(a_{1}\)
   a. For flat-plate, vacuum tube and concentrating collectors: \(A_{1,wind} \cdot f_{Area} = a_{1}\)b. For unglazed collectors: \(b_{1}\cdot f_{Area} = a_{1 }\)
3. Temperature dependence of the heat loss coefficient \(a_{2}\)
   a. For flat-plate, vacuum tube and concentrating collectors: \(A_{2} \cdot f_{Area} = a_{2 }\)
   b. For unglazed collectors: 0 = \(a_{2}\)
4. Wind speed dependence of the heat loss coefficient \(a_{3}\)
   a. For flat-plate, vacuum tube and concentrating collectors: 0 = \(a_{3}\)
   b. For unglazed collectors: \(b_{2} \cdot f_{Area} = a_{3 }\)
5. Sky temperature dependence of the heat loss coefficient \(a_{4}\)
   a. For flat-plate, vacuum tube and concentrating collectors: 0 = \(a_{4}\)
   b. For unglazed collectors: \(\frac{\epsilon}{\alpha} \cdot f_{Area} = a_{4}\)
6. Effective thermal capacity \(a_{5}\)
   a. \(\frac{c_{dyn}}{A_{gross}} = a_{5}\)
7. Wind speed dependence of the zero loss efficiency \(a_{6}\)
   a. For flat-plate, vacuum tube and concentrating collectors: 0 = \(a_{6}\)
   b. For unglazed collectors: \(\eta_{0,t} \cdot b_{u}\cdot f_{Area}^{2} = a_{6}\)
8. Effects of wind speed on radiation loss
   a. 0 = \(a_{7}\)
9. Radiation losses
   a. 0 = \(a_{8}\)
10. Diffuse IAM factor \(K_{d}\)
    a. For flat-plate, vacuum tube and concentrating collectors: \(K_{d} = 0.95\)
    b. For unglazed collectors: \(K_{d} = f_{diff}\)if \(f_{diff}\) is not set: \(K_{d} = 0.2\)
11. Volume
    \(V = max(V_{EN}, \frac{D_{pipe}^2}{4} \cdot \pi \cdot l_{pipe} \cdot p_{pipe})\)

The following table lists the parameters of the ASHRAE collectors.

The following calculations are used to convert the old collector data for ISO 9806:

1. Efficiency \(\eta_{0} = \eta_{0,b}\)
2. Heat loss coefficient \(a_{1}\)\(|A_{1}| = a_{1}\)
3. Temperature dependence of the heat loss coefficient \(a_{2}\)
   \(|A_{2}| = a_{2}\)
4. Wind speed dependence of the heat loss coefficient \(a_{3}\)
   \(a_{3} = \frac {a_{1}\cdot f_{c}-a_{1}}{3}\) where the coefficient is \(f_{c}\):
   a. For flat-plate collectors:
   \(f_{c} = 1.1 \frac{J}{m^3 K}\)
   b. For vacuum tube collectors:\(f_{c} = 1.05 \frac{J}{m^3 K}\)

   c. For unglazed and concentrating collectors:

   \(f_{c} = 1.2 \frac{J}{m^3 K}\)

5. Sky temperature dependence of the heat loss coefficient \(a_{4}\)\(0 = a_{4}\)
6. Effective thermal capacity \(a_{5}\)
   a. \(\frac{c_{dyn}}{A_{gross}} = a_{5}\)
   b. If the dynamic heat capacity was not specified: \(\frac{10’000}{A_ {gross}}\)
7. Wind speed dependence of the zero loss efficiency \(a_{6}\)\(0 = a_{6}\)
8. wind speed effect on radiation loss0 = \(a_{7}\)
9. Radiation loss0 = \(a_{8}\)
10. Diffuse IAM factor \(K_{d}\)
    a. For flat-plate and vacuum tube collectors with: \(K_{d} = 0.95\)
    b. For concentrating collectors: \(K_{d} = f_{diff}\)if \(f_{diff}\) is not set: \(K_{d} = 0.2\)
11. Volume\(V = max(V_{EN}, \frac{D_{pipe}^2}{4} \cdot \pi \cdot l_{pipe} \cdot p_{pipe})\)
12. Maximum temperature\(T_{max} =0\)
13. North-South axis \(N_{axis} = 0\)

The following table lists the parameters of the Chinese collectors.

The factor \(f_{Area}=\frac{A_{aperture}}{A_{gross}} \) is multiplied to all the old EN 12975 parameters and the following assumption were carried out to obtain the final ISO 9806 collector parameters:

1. Efficiency \(\eta_{0} \cdot f_{Area} = \eta_{0,b}\)
2. Heat loss coefficient \(a_{1} \)\(|A_{1}| \cdot f_{Area} = a_{1}\)
3. Temperature dependence of the heat loss coefficient \(a_{2}\)\(|A_{2}| \cdot f_{Area} = a_{2}\)
4. Wind speed dependence of the heat loss coefficient \(a_{3}\)\(a_{3} = \frac {a_{1}\cdot f_{c}-a_{1}}{3} \cdot f_{Area}\) where the coefficient is \(f_{c}\):
   a. For flat-plate collectors:\(f_{c} = 1.1 \frac{J}{m^3 K}\)

   b. For vacuum tube collectors:

   \(f_{c} = 1.05 \frac{J}{m^3 K}\)

   c. For unglazed and concentrating collectors:

   \(f_{c} = 1.2 \frac{J}{m^3 K}\)

5. Sky temperature dependence of the heat loss coefficient \(a_{4}\)\(0 = a_{4}\)
6. Effective thermal capacity \(a_{5}\)
   
   \(\frac{c_{dyn}}{A_{gross}} = a_{5}\)
7. Wind speed dependence of the zero loss efficiency \(a_{6}\)\(0 = a_{6}\)
8. Wind speed effect on radiation loss
   0 = \(a_{7}\)
9. Radiation loss
   0 = \(a_{8}\)
10. Diffuse IAM factor \(K_{d}\)
    a. For flat-plate and vacuum tube collectors with: \(K_{d} = 0.95\)b. For concentrating collectors: \(K_{d} = f_{diff}\)if \(f_{diff}\) is not set: \(K_{d} = 0.2\)
11. Volume
    \(V = max(V_{EN}, \frac{D_{pipe}^2}{4} \cdot \pi \cdot l_{pipe} \cdot p_{pipe})\)
12. Maximum temperature
    \(T_{max} =0\)
13. North-south axis
    \(N_{axis} = 0\)

This section describes the conversion of IAM types and data entries from the old catalogues to the k-values used in ISO 9806. The conversion rules are the same for all types of collectors and PVT collectors (Collector, CollectorAshrae, CollectorChina, PVTCollector, PVTCollectorAshrae).

The conversion model depends on the IAM model previously selected in the catalogue entry.

• IAM model «Ambrosetti» and «ASHRAE» \(k_{\gamma, i} = 1 – (tan(\frac{|\theta_{i}|}{2}))^{a_{\gamma}}\) \(a_{\gamma} = \frac{ln(1- iam_{value, \gamma})}{ln (tan(\frac {iam_{elevation, \gamma}}{2}))}\)
• IAM model «Table»
  In this case, the same angle factors are assigned to the k values.\(k_{l,i} = iam_{value, 0, i}\)
  \(k_{t,i} = iam_{value, 90, i}\)

  In the new catalog the k values are set in 10° intervals, starting at 10° until 90°. During the catalog conversion any intermediate values (e.g, 15°) will be ignored.

  If IAM values for some incidence angle between 10° and 90° with 10 ° interval were missing, these are calculated through a linear interpolation:

  \(k_{missing}=k_{previous}+(k_{next}-k_{previous})\cdot \frac{\theta_{missing}-\theta_{previous}}{\theta_{next}-\theta_{previous}} \)

  The starting values for the interpolation are 1 for the angle 0° and 0 for the angle of 90°. If the value at 10° is higher then 1, then the k value at 0 ° is set to the same value.