ᐅ Insufficient solar output; how to set up three flat-plate collectors
Created on: 28 Oct 2012 14:25
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Capone2000
Hello everyone,
We have been living in our beautiful house for several months now, which came with quite a few construction issues. We have managed to resolve most of them, but we are unsure whether our solar system is working correctly.
Here are the key details of our system:
We have a Vaillant solar system with three horizontal flat-plate collectors connected in series, one above the other. Total net surface area: 7.05m² (76 ft²)
Flow rate of the solar fluid: 2 l/min (0.53 gal/min) (the operating manual requires at least 3 l/min (0.79 gal/min), with a recommended flow of 4.6 l/min (1.22 gal/min))
Flow velocity in the circuit: 0.13 m/s (0.43 ft/s) (the manual requires a minimum of 0.4 m/s (1.31 ft/s); otherwise, the Vaillant venting system will not function properly)
Circulation pump type: Wilo RS25/7-3P; power consumption Stage 1: 62 W; Stage 2: 92 W; Stage 3: 132 W; set to Stage 2 as Stage 3 did not noticeably increase the volume flow.
According to Vaillant, this is a low-flow system and everything is fine.
But is that really the case?
We received a tip from a heating technician to check whether the system is set up for three flat-plate collectors, since factory settings often only cater to two collectors. We have searched through the manuals but could not find any setting options.
The controller is the Vaillant auroMATIC 620 model.
Despite repeated follow-ups with the plumbing company that installed the system and Vaillant, we have received no response or feedback for months.
We would greatly appreciate any insights or advice based on experience.
Good luck,
Thomas
We have been living in our beautiful house for several months now, which came with quite a few construction issues. We have managed to resolve most of them, but we are unsure whether our solar system is working correctly.
Here are the key details of our system:
We have a Vaillant solar system with three horizontal flat-plate collectors connected in series, one above the other. Total net surface area: 7.05m² (76 ft²)
Flow rate of the solar fluid: 2 l/min (0.53 gal/min) (the operating manual requires at least 3 l/min (0.79 gal/min), with a recommended flow of 4.6 l/min (1.22 gal/min))
Flow velocity in the circuit: 0.13 m/s (0.43 ft/s) (the manual requires a minimum of 0.4 m/s (1.31 ft/s); otherwise, the Vaillant venting system will not function properly)
Circulation pump type: Wilo RS25/7-3P; power consumption Stage 1: 62 W; Stage 2: 92 W; Stage 3: 132 W; set to Stage 2 as Stage 3 did not noticeably increase the volume flow.
According to Vaillant, this is a low-flow system and everything is fine.
But is that really the case?
We received a tip from a heating technician to check whether the system is set up for three flat-plate collectors, since factory settings often only cater to two collectors. We have searched through the manuals but could not find any setting options.
The controller is the Vaillant auroMATIC 620 model.
Despite repeated follow-ups with the plumbing company that installed the system and Vaillant, we have received no response or feedback for months.
We would greatly appreciate any insights or advice based on experience.
Good luck,
Thomas
H
Häuslebauer4013 Nov 2012 09:23Micha&Dany schrieb:
Hmm – Do you have solar thermal for heating support? Then the 500 liters (130 gallons) aren’t your drinking water; rather, the drinking water is heated by the 500 liters (130 gallons). In that case, Legionella in the storage tank doesn’t matter at all – so no testing is needed. (Regardless of who is right between you two *g*)
Best regards
Micha I don’t have solar thermal. Legionella is not an issue for me anyway, since the heat pump automatically runs a Legionella program at regular intervals. That probably heats the drinking water to 60°C (140°F).
I don’t really know how exactly the storage volume is divided. What mattered to me was just being able to fill my 350 liters (92 gallons) bathtub without running into cold water at the end.
Other than that, the heat comes from underfloor heating and electricity from the outlet—in other words, I haven’t really worried about the details.
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Bauminator14 Dec 2012 13:40We initially also had problems with our system. Then a service technician came to maintain the system...
Bauminator schrieb:
We initially had issues with our system as well. Then a service technician came to maintain it... So, how many kWh are actually generated compared to the forecast?Kind regards