ᐅ Ventilation System in a Single-Family Home Not Working – Planning Mistake?
Created on: 1 Feb 2021 19:35
J
jeti79
Hello everyone,
We have now been living for 2 years (since November 2018) in our detached house with a pitched roof, built according to the 2016 energy saving regulations, equipped with a central ventilation system (Wolf CWL300). Unfortunately, we have not been satisfied with the "performance" of the ventilation system from the start. We repeatedly called our installer in the beginning, but after about the eighth visit, he gave up and simply said, "The building is full of moisture at the beginning, so it’s normal for the air quality to be poor for two years." We consider this a poor excuse.
Our dissatisfaction mainly comes from the fact that we have had the chance to compare with neighboring houses (all in the same development with similar new build standards), where the air quality is usually significantly better than in our house. This means: despite the ventilation system running continuously (on occupancy mode at about 190 m³/h [190 cubic meters per hour]), the air in our house is almost always stuffy, whether we are home or not. Although the installer advised against it, we have actually been leaving the windows open every night lately because the air in the bedroom feels used up after 3-4 hours. It’s the same situation in the children's rooms.
Even when we come to the ground floor in the morning (where nobody has been all night), the air quality is anything but good. So, as we did before, we immediately open the windows in the morning.
Of course, I assume that we might be making some mistakes ourselves, but I would like to find out if there might also be (major?) planning errors in our system? Is it even possible to determine that remotely? What information would you need from us?
I have attached a layout showing how the supply and exhaust valves are installed on the upper and ground floors. The system is installed in the attic. I change the filters regularly every month (because it’s a new development), and the chimneys on the roof are the required >2.5 m (over 8 feet) apart from each other.
We have now been living for 2 years (since November 2018) in our detached house with a pitched roof, built according to the 2016 energy saving regulations, equipped with a central ventilation system (Wolf CWL300). Unfortunately, we have not been satisfied with the "performance" of the ventilation system from the start. We repeatedly called our installer in the beginning, but after about the eighth visit, he gave up and simply said, "The building is full of moisture at the beginning, so it’s normal for the air quality to be poor for two years." We consider this a poor excuse.
Our dissatisfaction mainly comes from the fact that we have had the chance to compare with neighboring houses (all in the same development with similar new build standards), where the air quality is usually significantly better than in our house. This means: despite the ventilation system running continuously (on occupancy mode at about 190 m³/h [190 cubic meters per hour]), the air in our house is almost always stuffy, whether we are home or not. Although the installer advised against it, we have actually been leaving the windows open every night lately because the air in the bedroom feels used up after 3-4 hours. It’s the same situation in the children's rooms.
Even when we come to the ground floor in the morning (where nobody has been all night), the air quality is anything but good. So, as we did before, we immediately open the windows in the morning.
Of course, I assume that we might be making some mistakes ourselves, but I would like to find out if there might also be (major?) planning errors in our system? Is it even possible to determine that remotely? What information would you need from us?
I have attached a layout showing how the supply and exhaust valves are installed on the upper and ground floors. The system is installed in the attic. I change the filters regularly every month (because it’s a new development), and the chimneys on the roof are the required >2.5 m (over 8 feet) apart from each other.
So ... Today, the field service technician from Wolf came by and took a look at the whole situation:
- In general, there is nothing to criticize about the valve positions from his perspective. They are certainly not placed according to the installation instructions, but the airflow is given and the air quality (as I was able to measure) is good. The keyword was “Dutch positioning.”
- The airflow volumes are somewhat unbalanced – for this, he is preparing a new ventilation concept (regarding the volumes) and will implement it if necessary, in case I can’t do it myself (which I assume).
- Dust deposits near the diffuser valves are considered normal, as there is a turbulence causing dust to settle there: it’s simply easy to clean.
- The ductwork is free of dirt and dust after about 30-40cm (12-16 inches) inside the pipe; this should also be easy to clean and is probably due to the system not running continuously.
- The trap of the mechanical ventilation system was clogged because it was installed with a slope towards the unit: not critical, but not ideal.
- The filters were fine overall but not the best quality; I am now switching to G4/G7 filters – this increases the workload on the device, but in a new build area, this is definitely worthwhile.
- Unfortunately, the power consumption is normal for this type of device: it is designed to protect against frost damage. The only option is to preheat the air, for example, through an air well or earth heat exchanger.
Mistakes we definitely made:
- We turned off the system during summer, at high temperatures, and only switched it on for 2-3 hours in the morning and evening for “shock ventilation” – a fatal mistake. The system should run continuously, even if only for moisture protection.
- Similarly, turning off the system in freezing temperatures to save electricity was wrong – it should rather continue running on “moisture protection” mode.
- The missing smart home connection is now being done via an RJ12 interface, switched through an actuator. Configuration will then be done using the ISM7E interface and the Wolf app.
Regarding too dry air in winter / too humid/stuffy/warm air in summer, we agreed that it is best to address these issues independently from the ventilation system: I am now fairly convinced that we will not manage without an air conditioning system to keep the indoor climate and temperatures within a comfortable range. I am hoping for a proper integration of photovoltaic inverter → KNX → air conditioning / mechanical ventilation to control indoor air quality according to internal and external conditions.
Thank you very much already for your input!
- In general, there is nothing to criticize about the valve positions from his perspective. They are certainly not placed according to the installation instructions, but the airflow is given and the air quality (as I was able to measure) is good. The keyword was “Dutch positioning.”
- The airflow volumes are somewhat unbalanced – for this, he is preparing a new ventilation concept (regarding the volumes) and will implement it if necessary, in case I can’t do it myself (which I assume).
- Dust deposits near the diffuser valves are considered normal, as there is a turbulence causing dust to settle there: it’s simply easy to clean.
- The ductwork is free of dirt and dust after about 30-40cm (12-16 inches) inside the pipe; this should also be easy to clean and is probably due to the system not running continuously.
- The trap of the mechanical ventilation system was clogged because it was installed with a slope towards the unit: not critical, but not ideal.
- The filters were fine overall but not the best quality; I am now switching to G4/G7 filters – this increases the workload on the device, but in a new build area, this is definitely worthwhile.
- Unfortunately, the power consumption is normal for this type of device: it is designed to protect against frost damage. The only option is to preheat the air, for example, through an air well or earth heat exchanger.
Mistakes we definitely made:
- We turned off the system during summer, at high temperatures, and only switched it on for 2-3 hours in the morning and evening for “shock ventilation” – a fatal mistake. The system should run continuously, even if only for moisture protection.
- Similarly, turning off the system in freezing temperatures to save electricity was wrong – it should rather continue running on “moisture protection” mode.
- The missing smart home connection is now being done via an RJ12 interface, switched through an actuator. Configuration will then be done using the ISM7E interface and the Wolf app.
Regarding too dry air in winter / too humid/stuffy/warm air in summer, we agreed that it is best to address these issues independently from the ventilation system: I am now fairly convinced that we will not manage without an air conditioning system to keep the indoor climate and temperatures within a comfortable range. I am hoping for a proper integration of photovoltaic inverter → KNX → air conditioning / mechanical ventilation to control indoor air quality according to internal and external conditions.
Thank you very much already for your input!
jeti79 schrieb:
- It was just as wrong to turn off the system during subzero temperatures to save electricity -> Better to let it run on “moisture protection” modeThanks for the feedback. What exactly is meant by moisture protection, and how is it related to the preheating coil?
No, that was not what I meant, sorry.
His urgent recommendation is to keep the system running 24/7, regardless of whether it is hot or cold outside.
Among other things, this also helps prevent dirt buildup and pest infestation. He personally suggests servicing/cleaning the entire system every 3-5 years.
His urgent recommendation is to keep the system running 24/7, regardless of whether it is hot or cold outside.
Among other things, this also helps prevent dirt buildup and pest infestation. He personally suggests servicing/cleaning the entire system every 3-5 years.
Bookstar schrieb:
They should learn from this. You can’t just turn off a Zehnder unit, and for good reason. Who should learn? Us? We have that now. The Wolf unit doesn’t have an off switch either.
jeti79 schrieb:
Who should learn more? Us? That’s what we have now. The Wolf unit also doesn’t have a power switch.I meant the company Wolf—they shouldn’t provide the option to turn it off.Similar topics