ᐅ Insufficient solar output; how to set up three flat-plate collectors
Created on: 28 Oct 2012 14:25
C
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
M
Micha&Dany4 Nov 2012 07:44€uro schrieb:
The question alone is already funny, as it clearly shows a significant lack of knowledge and detachment from reality! Anyone who assumes a three-phase connection from these power specifications clearly reveals the reliability of the assumptions made by "armchair experts". So, I am out of touch with reality because I am not an expert on heating pumps and therefore don’t know at which power levels these devices come with a three-phase connection... Aha... Okay...
Such a black-and-white view certainly makes life a lot easier...
I never claimed to be a pump expert. I just know that the pumps we use already have three-phase connections at less than 100 watts. It’s not always just about the power. There are other reasons why the load should be distributed across all three phases...
When a self-proclaimed expert has nothing better to do than point out the supposed mistakes of the person asking the question instead of helping or staying quiet, that is simply pathetic.
Regards,
Micha
Micha&Dany schrieb:
.... I only know that our pumps, which we use, already have a three-phase connection starting from under 100 watts.... Your "special pumps" have absolutely nothing to do with real technical building services! Hence, the apparently completely irrelevant comments! Seriously embarrassing! Micha&Dany schrieb:
....If a self-proclaimed expert .... Whether someone is "self-proclaimed" is for the interested reader to decide. Regards
M
Micha&Dany5 Nov 2012 20:23€uro schrieb:
Your "special pumps" have nothing at all to do with real HVAC home technology!!! But they are all standard heating pumps from well-known manufacturers. Nothing special. Just because I am *allowed* to connect up to 4.6 kVA single-phase doesn’t mean it makes any sense.
But it doesn’t matter anyway. I suggest we leave this topic here – it’s off-topic and pointless.
Best regards
Micha
B
Bauexperte12 Nov 2012 12:08Hello €uro,
Our heating engineer is currently writing a report, and then I will see how to proceed, and who I might need to hold accountable!
Vaillant is definitely not my preferred contact among the three... I should probably explain to them the meaning of the word “customer service”... It’s appalling, as I am currently experiencing firsthand...
For one of our new builds, Vaillant will certainly no longer be considered. Even before this “experience,” I had discussed with every plumbing company that mentioned this supplier. Now the matter is finally closed!
Best regards
€uro schrieb:The supplier installed a hot water storage tank that is too large for the house (400 liters (105 gallons) for 2 people); the planner/plumbing company/Vaillant should have noticed this – as a result, the solar thermal system is, simply put, “overloaded.” In addition, my clients are now subject to recurring Legionella testing by the health department (mandatory since 10/2011), which naturally costs money. They also failed to install an access opening for this inspection, meaning the hot water tank would have to be dismantled every time... I just shake my head at that...
I would be interested in the result!
Our heating engineer is currently writing a report, and then I will see how to proceed, and who I might need to hold accountable!
Vaillant is definitely not my preferred contact among the three... I should probably explain to them the meaning of the word “customer service”... It’s appalling, as I am currently experiencing firsthand...
For one of our new builds, Vaillant will certainly no longer be considered. Even before this “experience,” I had discussed with every plumbing company that mentioned this supplier. Now the matter is finally closed!
Best regards
H
Häuslebauer4012 Nov 2012 13:56Bauexperte schrieb:
The supplier installed an oversized hot water storage tank for the house (400 liters (106 gallons) for 2 people); the planner/plumbing company/Vaillant should have noticed this – as a result, the solar system is, simply put, "overstrained." Additionally, my clients will have to undergo recurring legionella testing by the health department (mandatory since 10/2011), which naturally costs money. They also neglected to include an access opening for this inspection, meaning the storage tank would have to be removed every time...! 2 people? But single- and two-family homes are usually exempt from legionella testing, aren’t they?
Excerpt from the Drinking Water Ordinance 2001 after the amendment on 1.11.2011:
Single- and two-family homes are, by definition, not subject to mandatory legionella testing according to the Drinking Water Ordinance 2001.B
Bauexperte12 Nov 2012 15:13Hello,
"c[O]mprehensive new regulations also apply to the parameter 'legionella.' A technical action threshold (100 legionella per 100 milliliters (3.4 fluid ounces) of drinking water) is introduced, and if necessary, an on-site inspection of the affected drinking water installation and a risk assessment are required.
In principle, tests for legionella are required for drinking water heating systems within the drinking water installation (see § 9 section 8, § 13 section 5, § 14 section 3, Annex 3 Part II and Annex 4 Part II letter b of the Drinking Water Ordinance 2011). This applies to all operators and other holders of drinking water installations in which there is a large-scale drinking water heating system according to the definition of the generally accepted rules of technology, provided that drinking water is supplied from this system as part of a public or commercial activity.
The testing obligation applies to systems that include, for example, showers or other facilities where drinking water is aerosolized (so not for hand washbasins in a restaurant’s restroom). Large-scale drinking water systems are storage-type drinking water heaters or central flow-type drinking water heaters [/I]
with a capacity of more than 400 liters (105 gallons) and/or 3 liters (0.8 gallons) in every pipe between the outlet of the drinking water heater and the point of use (see DVGW worksheet W 551)."
Kind regards
Häuslebauer40 schrieb:Another typical case of VRI, because
2 people? But single-family and two-family houses are generally exempt from legionella testing, aren’t they?
Excerpt from the Drinking Water Ordinance 2001 after the amendment on 1.11.2011:
"c[O]mprehensive new regulations also apply to the parameter 'legionella.' A technical action threshold (100 legionella per 100 milliliters (3.4 fluid ounces) of drinking water) is introduced, and if necessary, an on-site inspection of the affected drinking water installation and a risk assessment are required.
In principle, tests for legionella are required for drinking water heating systems within the drinking water installation (see § 9 section 8, § 13 section 5, § 14 section 3, Annex 3 Part II and Annex 4 Part II letter b of the Drinking Water Ordinance 2011). This applies to all operators and other holders of drinking water installations in which there is a large-scale drinking water heating system according to the definition of the generally accepted rules of technology, provided that drinking water is supplied from this system as part of a public or commercial activity.
The testing obligation applies to systems that include, for example, showers or other facilities where drinking water is aerosolized (so not for hand washbasins in a restaurant’s restroom). Large-scale drinking water systems are storage-type drinking water heaters or central flow-type drinking water heaters [/I]
with a capacity of more than 400 liters (105 gallons) and/or 3 liters (0.8 gallons) in every pipe between the outlet of the drinking water heater and the point of use (see DVGW worksheet W 551)."
Kind regards
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