Как выбрать гостиницу для кошек
14 декабря, 2021
The effect of the significantly higher performance levels of COAX 390 (heat insulation and heat transfer ability) has been tested in a simulation in Polysun. The experiment has been carried out for a solar thermal system with COAX 390 as well as two or three flat collectors PLANO 21 (figure 4) in comparison to a conventional tank with the same collectors (climate Wurzburg).
Table 1 shows the different parameters. The values for heat losses of the connected pipes are taken from /1/.
Parameter |
Conventional tank |
COAX 390 |
Thickness insulation |
100 mm |
125 mm |
Thermal conductivity insulation |
0.049 W/(m K) (PU-foam, soft) |
0.033 W/(m K) (LE-EPS + air) |
Losses connections boiler supply, boiler return, cold water |
10 W/(50°C — 20°C) = 0.33 W/K |
0,9 W / (50°C — 20 °C) = 0.03 W/K |
Losses connection hot water |
15 W / 30K = 0.5 W/K |
0.9 W / 30K = 0.03 |
Without even considering the additional yield through stratification, the COAX-system offers with the two tested factors alone a higher solar yield of 8 % or 14 %, respectively.
The substantial performance improvements of COAX 390 (achieved by stratification, heat transfer values, insulation) in comparison to the market standard leads to the conclusion that — when using the same collector area — a significantly higher energy yield can be achieved.
On the other hand, the cost for this tank is comparable to high-quality yet technically conventional tanks, which should lead to an extremely good price/performance ratio for the complete system.
/1/ Meitner, R., Siegemund, A., Leibfried, U.: Mit Mehrtagesspeichern gegen Warmev — erluste, Moderne Gebaudetechnik 10/2001
Tr_COAX_14_SYMPOS_as. doc