ᐅ 1 Year with the Ventilation System: Clarity, Facts, and Energy Costs
Created on: 27 Aug 2013 23:56
B
Bastelwastel
Hello, this is my first post here in the forum,
this post is meant to provide practical facts for those who are still undecided!
We have been living in our new build for 2.5 years now, and since August of last year I have been diligently recording the gas meter readings and entering them into a spreadsheet. I compared the actual consumption values with the forecasted values from the energy certificate, resulting in a nice consumption statistic for the billing period 2012/2013.
About the house:
Single-family house, two stories, with 220 sqm (2370 sq ft) plus a full basement.
Basement: waterproof concrete, insulation?
Ground floor and first floor: cavity brickwork, insulation 0.35 from Knauf, 15 cm (6 inches) (the black one)
Windows: triple-glazed with external blinds, large window front facing southwest
Heating: underfloor heating, gas condensing boiler with solar hot water and heating support
Ventilation: Paul Novus 300 (with touchscreen display)
Back when planning, we had to insist quite strongly on the ventilation system since it was new territory even for our architect. And today I can say YES, the money was worth it.
In our energy certificate prepared by the structural engineer, the ventilation system was not included. We arrived at a value of 69 kWh/sqm per year (kWh/sqm a).
Now the E.On billing year has "finally" ended and I was able to do the evaluation.
Despite the rather long winter (in April and May we consumed much more than in the energy certificate forecast), we ended up with a consumption value of 56 kWh/sqm per year (kWh/sqm a). Since domestic hot water energy is included in this figure, the number of occupants is also important. We live in the house with two adults and two small children.
Because I installed two small electricity meters (about the size of a circuit breaker) during the electrical installation, I know exactly how much the ventilation system and how much the heating and solar system including all pumps etc. consumed.
Ventilation: 323 kWh
Heating: 383 kWh
Regarding ventilation in general: simply brilliant!
The Novus 300 at our place is set to the normal load of 60% and it runs every day. At night on level 1 (power 20%) and when necessary on level 3 (which I set to 100%).
The comfort gain is mainly noticeable in winter.
One example:
In the evening after showering or bathing, everything is wet. What do you do when you're done? Open the window and let in the -10°C (14°F) cold air or just tilt it and then forget to close it, and in the morning you freeze on the toilet seat and the radiator thermostat runs full power because of frost protection.
BUT! Not in our house, because we keep the windows closed and the ventilation system takes care of the rest (then on level 2). In the morning it's not musty and everything is dry.
Second example:
We have a utility room on the ground floor with an exhaust vent where we dry laundry, and this works very quickly thanks to the constant air exchange while the windows remain closed (great for anyone with pollen allergies).
What I have often heard is that some are afraid there might be drafts at the doors or whistling noises. We don’t have that problem, even at full power. For the glass doors, the frames were simply installed slightly higher to allow an air gap. The best way to demonstrate the airflow is with a lighter flame or standing barefoot directly at the bathroom door—that’s when you realize what’s happening.
One negative issue:
I made the supply and exhaust air ducts through the basement light wells to the outside ("special basement windows"). Normally no problem, but at the exhaust air shaft the air noise is clearly audible and that is also where the terrace is, which is a little annoying. But when we sit there in summer, we just turn the system off or set it to level 1.
I could list many more positive examples.
If anyone has questions, feel free to contact me! I’m happy if I can help.
P.S.: I am not a salesperson and have absolutely NOTHING to do with the mentioned companies!
this post is meant to provide practical facts for those who are still undecided!
We have been living in our new build for 2.5 years now, and since August of last year I have been diligently recording the gas meter readings and entering them into a spreadsheet. I compared the actual consumption values with the forecasted values from the energy certificate, resulting in a nice consumption statistic for the billing period 2012/2013.
About the house:
Single-family house, two stories, with 220 sqm (2370 sq ft) plus a full basement.
Basement: waterproof concrete, insulation?
Ground floor and first floor: cavity brickwork, insulation 0.35 from Knauf, 15 cm (6 inches) (the black one)
Windows: triple-glazed with external blinds, large window front facing southwest
Heating: underfloor heating, gas condensing boiler with solar hot water and heating support
Ventilation: Paul Novus 300 (with touchscreen display)
Back when planning, we had to insist quite strongly on the ventilation system since it was new territory even for our architect. And today I can say YES, the money was worth it.
In our energy certificate prepared by the structural engineer, the ventilation system was not included. We arrived at a value of 69 kWh/sqm per year (kWh/sqm a).
Now the E.On billing year has "finally" ended and I was able to do the evaluation.
Despite the rather long winter (in April and May we consumed much more than in the energy certificate forecast), we ended up with a consumption value of 56 kWh/sqm per year (kWh/sqm a). Since domestic hot water energy is included in this figure, the number of occupants is also important. We live in the house with two adults and two small children.
Because I installed two small electricity meters (about the size of a circuit breaker) during the electrical installation, I know exactly how much the ventilation system and how much the heating and solar system including all pumps etc. consumed.
Ventilation: 323 kWh
Heating: 383 kWh
Regarding ventilation in general: simply brilliant!
The Novus 300 at our place is set to the normal load of 60% and it runs every day. At night on level 1 (power 20%) and when necessary on level 3 (which I set to 100%).
The comfort gain is mainly noticeable in winter.
One example:
In the evening after showering or bathing, everything is wet. What do you do when you're done? Open the window and let in the -10°C (14°F) cold air or just tilt it and then forget to close it, and in the morning you freeze on the toilet seat and the radiator thermostat runs full power because of frost protection.
BUT! Not in our house, because we keep the windows closed and the ventilation system takes care of the rest (then on level 2). In the morning it's not musty and everything is dry.
Second example:
We have a utility room on the ground floor with an exhaust vent where we dry laundry, and this works very quickly thanks to the constant air exchange while the windows remain closed (great for anyone with pollen allergies).
What I have often heard is that some are afraid there might be drafts at the doors or whistling noises. We don’t have that problem, even at full power. For the glass doors, the frames were simply installed slightly higher to allow an air gap. The best way to demonstrate the airflow is with a lighter flame or standing barefoot directly at the bathroom door—that’s when you realize what’s happening.
One negative issue:
I made the supply and exhaust air ducts through the basement light wells to the outside ("special basement windows"). Normally no problem, but at the exhaust air shaft the air noise is clearly audible and that is also where the terrace is, which is a little annoying. But when we sit there in summer, we just turn the system off or set it to level 1.
I could list many more positive examples.
If anyone has questions, feel free to contact me! I’m happy if I can help.
P.S.: I am not a salesperson and have absolutely NOTHING to do with the mentioned companies!
Steusel schrieb:
but in Halstenbek. It's near Hamburg.I know that place ... Schulenburg, Riess, and so on. We go there at least once a year.
Häuslebau3r18 Feb 2015 08:30Now I have to ask a probably silly question, because my partner would really like to have a mezzanine, and so far I have always been against it due to the potentially higher energy demand for heating. Is that really the case, or do you simply lose a few square meters of usable space upstairs?
Häuslebau3r schrieb:
Now I need to ask a probably silly question, since my partner really wants a gallery, and until now I have generally been against it because of the possibly higher heating load, meaning warming up the space. Is that really the case, or do you simply lose a few square meters of floor space that you no longer have upstairs? Does this matter in our insulated new builds? Considering that many people opt for higher ceilings on the ground floor... See the above comparison of the cubic meters. I don’t think so.
Häuslebau3r18 Feb 2015 13:18ypg schrieb:
Does this matter for our insulated new builds? Considering that many allow for higher ceilings on the ground floor... See the comparison of cubic meters above? I don't think so.
Yes, I actually think now, or rather by now, that it doesn’t really make much of a difference anymore. I used to think differently about that in the past, hmm...
Here are the actual facts about ventilation systems: In our new single-family house, we have a CWL400 ventilation unit from Wolf. With a manufacturer-recommended basic ventilation rate of 295 m³/h (173 cubic feet per hour), the device consumes a hefty 170 W. This value matches the CWL datasheet from Wolf (note that Wolf specifies power consumption per fan motor, so the value should be doubled. The maximum consumption is actually 336 W). Calculated over a year, this amounts to a significant 1489 kWh and corresponds to about €357 at a rate of 24 cents per kWh. I find this consumption quite high, as it accounts for roughly 25% of our electricity usage, or nearly half of our heating costs in euros! Of course, you can reduce the airflow to lower the power consumption to about 25 watts, but then you are far from the manufacturer’s recommendations. I find it strange that electricity consumption is almost always downplayed as negligible.
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toxicmolotof23 Mar 2015 13:04Whether one is a supporter or opponent of such systems is not up for discussion here, but it should be pointed out that Werwolf only considered one side of the cost/benefit analysis.
How much energy was retained in the house through heat recovery and therefore did not need to be "produced" in the first place?
How much energy was retained in the house through heat recovery and therefore did not need to be "produced" in the first place?
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