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
H
Häuslebauer4012 Nov 2012 15:41In this case, I do not share your opinion, Bauexperte.
The information from the Federal Health Office states very clearly, as quoted here in full without omitting any lines or paragraphs:
In my, albeit layperson’s, legal understanding, single- and two-family houses are therefore definitely exempt from the testing requirement, regardless of the storage size.
If not done already, you might want to have this fact reviewed again by an administrative law expert in the interest of your clients, who already have enough trouble in this particular case.
The information from the Federal Health Office states very clearly, as quoted here in full without omitting any lines or paragraphs:
Large systems are all systems with storage-type domestic water heaters or central flow-through domestic water heaters, e.g., in residential buildings, hotels, hospitals, and systems with domestic water heaters having a capacity of more than 400 liters (about 105 gallons) or more than 3 liters (about 0.8 gallons) in a pipe between the outlet of the domestic water heater and the point of use (see DVGW worksheet W 551).
Single- and two-family houses are by definition not subject to mandatory Legionella testing according to the Drinking Water Ordinance 2001.
In my, albeit layperson’s, legal understanding, single- and two-family houses are therefore definitely exempt from the testing requirement, regardless of the storage size.
If not done already, you might want to have this fact reviewed again by an administrative law expert in the interest of your clients, who already have enough trouble in this particular case.
B
Bauexperte12 Nov 2012 16:03Hello,
Kind regards
Häuslebauer40 schrieb:You don’t have to – it doesn’t change the facts, because
In this case, I do not agree with you, Bauexperte.
Häuslebauer40 schrieb:that will not be necessary, as the storage tank will be replaced with a smaller unit in the foreseeable future. If it were different, I would already be causing office towers to stir.
If not done yet, you should have this situation reviewed again by an administrative law expert on behalf of your clients, who already have enough trouble in this matter.
Kind regards
H
Häuslebauer4012 Nov 2012 16:19Bauexperte schrieb:
Hello,
You don’t have to do that either – it doesn’t change the situation because
this won’t be necessary, as the storage tank will be replaced with a smaller unit in the foreseeable future. If it were otherwise, I would already be stirring up entire office buildings.
Kind regardsOk, then that’s settled anyway.
I was just a bit surprised because I’ve only heard about it myself, and actually I should be familiar with it since I also have a 500-liter (132-gallon) water storage tank (which I do need).
M
Micha&Dany12 Nov 2012 17:39Häuslebauer40 schrieb:
[...]since I also have a 500-liter (130-gallon) water storage tank myself (I do need it, though) Is it only a potable water storage tank or a combined tank for potable water and heating?
H
Häuslebauer4012 Nov 2012 18:25Micha&Dany schrieb:
Only domestic hot water storage tanks or combined storage tanks for domestic hot water and heating??Since the total capacity is 500 liters (130 gallons), I assume it is a combined storage tank.
M
Micha&Dany13 Nov 2012 08:50Häuslebauer40 schrieb:
Since the total volume is 500 liters (132 gallons), I assume it is a combined storage tank.Hmm – Do you have solar thermal (ST) for heating support? In that case, the 500 liters (132 gallons) are not your potable water, but used to heat the potable water. This means that legionella in the storage tank is completely irrelevant – so no testing is necessary. (Regardless of which one of you is actually right *g*)
Regards
Micha