ᐅ Central or Decentralized Ventilation System – Who Has Experience?
Created on: 26 Feb 2018 10:48
G
Gerd&Jolanthe
Hello everyone,
We are going to build a single-family house to KfW55 standard. It will have a basement, ground floor, and upper floor. The living area is approximately 170m² (1830 sq ft) and the usable area 108m² (1163 sq ft) including stairs and basement – that’s the basic information.
Now we are wondering which ventilation system to choose, since new builds are very airtight due to the windows and insulation.
We were recommended a decentralized system, as it would be fully sufficient and requires less frequent maintenance and cleaning. Additionally, cleaning is easier and less problematic compared to a central ventilation system.
Could you share your views or experiences on which ventilation system would be most suitable?
Thank you very much.
We are going to build a single-family house to KfW55 standard. It will have a basement, ground floor, and upper floor. The living area is approximately 170m² (1830 sq ft) and the usable area 108m² (1163 sq ft) including stairs and basement – that’s the basic information.
Now we are wondering which ventilation system to choose, since new builds are very airtight due to the windows and insulation.
We were recommended a decentralized system, as it would be fully sufficient and requires less frequent maintenance and cleaning. Additionally, cleaning is easier and less problematic compared to a central ventilation system.
Could you share your views or experiences on which ventilation system would be most suitable?
Thank you very much.
G
Gerd&Jolanthe27 Feb 2018 10:14There are also decentralized ventilators that require only one hole in the exterior wall and can then ventilate four additional rooms. This way, an entire floor can be ventilated. This provides the advantages of both decentralized and centralized ventilation systems.
There are some disadvantages to centralized ventilation systems as well.
Prefabricated houses are usually sold with or offer only controlled mechanical ventilation. Due to construction reasons, this is the case with solid building methods as well, and apparently, it is more profitable for companies.
There are some disadvantages to centralized ventilation systems as well.
Prefabricated houses are usually sold with or offer only controlled mechanical ventilation. Due to construction reasons, this is the case with solid building methods as well, and apparently, it is more profitable for companies.
R
readytorumble27 Feb 2018 10:42Gerd&Jolanthe schrieb:
There are plenty of reasons against a central ventilation system, which are usually not mentioned by the companies.Then go ahead and list them.
Yes, now think about this logically...
A single fan installed in a wall that ventilates only one room is sometimes already too loud, etc.
Now imagine one fan in one room that is supposed to exchange air in FOUR rooms. Simply put, about four times the amount of air needs to be circulated.
What do you think—will the fan be louder or quieter? Will it consume more or less electricity? And will the intervals between filter changes become shorter or longer?
What would those be? (Apart from the cost)
And don’t bring up dirty ducts—that’s just a myth.
No, they simply don’t want the houses to deteriorate within the warranty period, forcing the manufacturer to renovate because the homeowner did not ventilate sufficiently.
A single fan installed in a wall that ventilates only one room is sometimes already too loud, etc.
Now imagine one fan in one room that is supposed to exchange air in FOUR rooms. Simply put, about four times the amount of air needs to be circulated.
What do you think—will the fan be louder or quieter? Will it consume more or less electricity? And will the intervals between filter changes become shorter or longer?
Gerd&Jolanthe schrieb:
There are certain disadvantages to centralized ventilation systems.
What would those be? (Apart from the cost)
And don’t bring up dirty ducts—that’s just a myth.
Gerd&Jolanthe schrieb:
Prefabricated houses only sell or offer controlled ventilation systems. Due to construction methods, it cannot be done differently than in solid construction, and apparently, companies see greater profit there.
No, they simply don’t want the houses to deteriorate within the warranty period, forcing the manufacturer to renovate because the homeowner did not ventilate sufficiently.
D
Deliverer27 Feb 2018 15:40To the Original Poster: There are numerous threads on this topic. Try using the search function.
Besides central and decentralized mechanical ventilation systems with heat recovery, there are also more affordable exhaust ventilation systems. The fresh air supply comes through vents in the windows. This design also works and has its proponents.
In the end, you have to decide what to install and how much you want to invest. If possible, I would advise against relying solely on information from the internet!
Besides central and decentralized mechanical ventilation systems with heat recovery, there are also more affordable exhaust ventilation systems. The fresh air supply comes through vents in the windows. This design also works and has its proponents.
In the end, you have to decide what to install and how much you want to invest. If possible, I would advise against relying solely on information from the internet!
Hello,
I have a Paul Novus 450 with an enthalpy exchanger. I was also deciding between the Zehnder Comfoair 550 and Paul. These brands belong to the same company, as Zehnder acquired Paul.
The advantage of Paul units is that they are volumetrically controlled, meaning that even when filters get dirty, the system compensates to always provide a consistent airflow.
With an actuator that measures power consumption, you can easily detect potential issues. For example, if the intake grille freezes up during heavy snow, the system will increase the fan speed to maintain the airflow, causing higher power consumption. This way, you can detect the problem and, if necessary, shut down the unit until it is fixed.
In general, you can also quite easily control some functions directly without additional external controllers, either potential-free or via 0-10V signals. This includes things like boost ventilation or adjusting the fan speed. I had email contact with Paul about this and received good support.
Regarding noise:
I have the system installed in the basement utility room. There is a silencer and a distribution box behind it. The duct length to this point is around 4 m (13 feet). The duct length from the silencer to the bedroom is about 16 m (52 feet).
During normal operation at 20-30% speed, you can hardly hear anything. It’s also not noticeable in the guest room in the basement, even though the duct there is shorter.
In the mornings, around wake-up time, I run a 20-minute boost ventilation at roughly 90-95%, which is basically full power. Even then, in a very quiet room, you only hear a soft rustle.
After almost 1.5 years, I consider the improved indoor air quality as one of the best factors for living comfort, even putting aside the energetic benefits. Although you don’t notice it immediately. We previously lived in a fairly modern attic apartment that was well sealed but without ventilation. You could always notice the air getting stale or worse during the day.
As a comparison, I know someone who has these air boxes in every room. After a few years, they painted them on the outside from silver to a brick color to make them less visible. Apparently, small birds also nest in the grilles or metal covers outside. I think these units cost about 300/350 €.
These are clearly noticeable when running, even during TV watching. I couldn’t fall asleep with them running. But these units are about 6 years old, so maybe things have improved since then. Although due to their design, a smaller fan is naturally louder. I also suspect that the heat exchangers’ efficiency isn’t as good. I don’t know if enthalpy exchangers exist for these indirect units.
The main issue with this type of installation is that it lacks a central control system. So the units are often off or only run at minimum speed. If choosing decentralized ventilation, definitely include a central controller. This way, you can run the units occasionally or comfortably turn them off if they become annoying.
In terms of cost, I estimate that central systems roughly cost twice as much, at least when using Paul and Zehnder components.
I have a Paul Novus 450 with an enthalpy exchanger. I was also deciding between the Zehnder Comfoair 550 and Paul. These brands belong to the same company, as Zehnder acquired Paul.
The advantage of Paul units is that they are volumetrically controlled, meaning that even when filters get dirty, the system compensates to always provide a consistent airflow.
With an actuator that measures power consumption, you can easily detect potential issues. For example, if the intake grille freezes up during heavy snow, the system will increase the fan speed to maintain the airflow, causing higher power consumption. This way, you can detect the problem and, if necessary, shut down the unit until it is fixed.
In general, you can also quite easily control some functions directly without additional external controllers, either potential-free or via 0-10V signals. This includes things like boost ventilation or adjusting the fan speed. I had email contact with Paul about this and received good support.
Regarding noise:
I have the system installed in the basement utility room. There is a silencer and a distribution box behind it. The duct length to this point is around 4 m (13 feet). The duct length from the silencer to the bedroom is about 16 m (52 feet).
During normal operation at 20-30% speed, you can hardly hear anything. It’s also not noticeable in the guest room in the basement, even though the duct there is shorter.
In the mornings, around wake-up time, I run a 20-minute boost ventilation at roughly 90-95%, which is basically full power. Even then, in a very quiet room, you only hear a soft rustle.
After almost 1.5 years, I consider the improved indoor air quality as one of the best factors for living comfort, even putting aside the energetic benefits. Although you don’t notice it immediately. We previously lived in a fairly modern attic apartment that was well sealed but without ventilation. You could always notice the air getting stale or worse during the day.
As a comparison, I know someone who has these air boxes in every room. After a few years, they painted them on the outside from silver to a brick color to make them less visible. Apparently, small birds also nest in the grilles or metal covers outside. I think these units cost about 300/350 €.
These are clearly noticeable when running, even during TV watching. I couldn’t fall asleep with them running. But these units are about 6 years old, so maybe things have improved since then. Although due to their design, a smaller fan is naturally louder. I also suspect that the heat exchangers’ efficiency isn’t as good. I don’t know if enthalpy exchangers exist for these indirect units.
The main issue with this type of installation is that it lacks a central control system. So the units are often off or only run at minimum speed. If choosing decentralized ventilation, definitely include a central controller. This way, you can run the units occasionally or comfortably turn them off if they become annoying.
In terms of cost, I estimate that central systems roughly cost twice as much, at least when using Paul and Zehnder components.
We also installed a central ventilation system from Zehnder, and I can only recommend it. When I lived in a rental apartment, I once had decentralized fans from Meltec, and it was a disaster. They are noisy, get dirty quickly, have poor heat recovery efficiency, and cause additional noise from the drill holes.
A central system has only advantages... except for the price. Nowadays, you’re probably looking at 15,000 to 20,000 euros for a typical single-family house.
A central system has only advantages... except for the price. Nowadays, you’re probably looking at 15,000 to 20,000 euros for a typical single-family house.
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