Solar installations require special attention to maintain pressure in the circuit. A solar circuit with strong temperature variations between day and night, causes strong variations in dilation.
The only organ capable of maintaining this pressure is the expansion vessel.
The collector is at the highest point of the installation, it is vital that it is at the pressure is correct.
The calculation of the solar vessel is specific:
Several parameters must be taken into account:
Without taking these factors into account, the glass is usually smaller. The solar liquid, based on glycol, escapes through the valve, when the temperature rises. This loss of liquid causes a lack of water in the collector, it can not be more efficient and its performance will be drastically reduced.
In a solar installation, the expansion vessel must respond to some vital criteria for the installation:
Minimal pressure loss. In fact, a pressure loss of more than 5% causes a deflation of the vessel, followed by a pressure drop in the installation and a significant loss in the performance of the collector. Compatibility of "glycol" fluidsInstallation ofindividual solar waterheaters
Installation of 20 liters of 30% glycol
Max 110°C
2 collectors with capacity: 3 liters
Height of 7 m Tara 3 bars
Volume to be absorbed:
Vnet = 1.2 + 3 + 3
Fill pressure
P0 = 0.7 + 0.3 = 1
Glass yield = (2.5-1)/3.5 = 43%
In this configuration, with different fill pressures should be consulted
On an 18-liter glass
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Authors: Javier Gainza
