Good day,
I am new here and hope you can help me (even though I am not currently building myself):
We recently moved into a newly painted apartment on the third floor; the building was constructed just before the turn of the millennium.
I noticed that the windows, especially in the mornings in the bedroom, office, and kitchen, are fogged up on the inside edges and have visible water droplets. The windows are partly older wooden windows and partly skylights with metal frames.
I then bought two thermometers/hygrometers from TFA and placed them in the bedroom and kitchen. The humidity levels were between 60-70%.
I have read up online and gathered a lot of tips. We ventilate at least twice a day, usually more often, by fully opening windows for 5-10 minutes maximum, with heating off during this time. The temperature in all rooms is between 19 and 20°C (66-68°F). Laundry is not dried inside the apartment; after showering and cooking, we also ventilate thoroughly and turn on the extractor fan, as well as when the washing machine is running.
Although we notice that during ventilation, the humidity drops to around 40-45%, it rises again within minutes to at least 53% and then slowly moves toward 56-60%. In the morning, the bedroom is about 63-68%, and the kitchen 61-67% (humidity even goes higher during cooking despite ventilation).
We have moisture-absorbing granules in the kitchen and bedroom, but unfortunately, they haven’t made any improvement.
I did not experience this problem at all in my previous apartment and am currently unsure what to do. I plan to start documenting this in writing and then address it with the landlord, but I wanted to ask here first if anyone has any further tips on what I might try.
Thank you very much.
Best regards,
bpe87
I am new here and hope you can help me (even though I am not currently building myself):
We recently moved into a newly painted apartment on the third floor; the building was constructed just before the turn of the millennium.
I noticed that the windows, especially in the mornings in the bedroom, office, and kitchen, are fogged up on the inside edges and have visible water droplets. The windows are partly older wooden windows and partly skylights with metal frames.
I then bought two thermometers/hygrometers from TFA and placed them in the bedroom and kitchen. The humidity levels were between 60-70%.
I have read up online and gathered a lot of tips. We ventilate at least twice a day, usually more often, by fully opening windows for 5-10 minutes maximum, with heating off during this time. The temperature in all rooms is between 19 and 20°C (66-68°F). Laundry is not dried inside the apartment; after showering and cooking, we also ventilate thoroughly and turn on the extractor fan, as well as when the washing machine is running.
Although we notice that during ventilation, the humidity drops to around 40-45%, it rises again within minutes to at least 53% and then slowly moves toward 56-60%. In the morning, the bedroom is about 63-68%, and the kitchen 61-67% (humidity even goes higher during cooking despite ventilation).
We have moisture-absorbing granules in the kitchen and bedroom, but unfortunately, they haven’t made any improvement.
I did not experience this problem at all in my previous apartment and am currently unsure what to do. I plan to start documenting this in writing and then address it with the landlord, but I wanted to ask here first if anyone has any further tips on what I might try.
Thank you very much.
Best regards,
bpe87
B
Bieber081513 Feb 2018 09:22bpe87 schrieb:
fluctuating between 20-21°C (68-70°F). The humidity is around 50-55%, [...] Yet, even with these values, the windows have been damp on the inner edges in the mornings and evenings, one even quite extensively... Is this normal due to the cold outside temperatures? Can I reduce this somehow? With those values, simply ventilating seems to me to be too simplistic advice. What really matters are the dew point and surface temperature. At 20°C (68°F) and 55% relative humidity, the dew point is 10.7°C (51°F). This means that condensation from water vapor in the air occurs on surfaces at or below 10.7°C (51°F). (Everyone knows the experience of glasses fogging up when coming indoors from outside...)
Apparently, the inner surfaces of your windows are rather cold, below 11°C (52°F). I would suggest wiping the windows dry in the mornings. From my point of view, this is not particularly critical.
It becomes critical if the humidity causes condensation not only on the windows but also in room corners on the wallpaper or behind a skirting board. In such places, the moisture cannot be wiped away and can provide a breeding ground for mold. Heating would help to some extent, and even better would be eliminating thermal bridges so that no surface falls below 11°C (52°F).
Heating only helps to a limited degree because increasing the room temperature has little effect on surface temperature. The latter mainly depends on the outside temperature and the thermal conductivity of the building element. You can only influence the thermal conductivity. Clearly, this is a structural issue.
So, why can ventilation still help? :P If you ventilate to the often found 40% relative humidity indoors during winter (at 20°C room temperature), the dew point drops to 6°C (43°F) from just under 11°C (52°F) previously. This means the surface must be considerably colder before vapor condenses.
Hessy-James17 Feb 2018 15:06Hi.
Maybe one could install a decentralized ventilation system with heat recovery?
Just an idea, since you often hear about the air being a bit dry.
Maybe one could install a decentralized ventilation system with heat recovery?
Just an idea, since you often hear about the air being a bit dry.
Thank you for the replies. Of course, I always dry the windows. However, I have to say that I find it quite annoying, and with wooden frames, it will probably still cause issues over time. But as a tenant, there isn't much more I can do besides regularly airing out the rooms, heating properly, and drying the windows. I have already mentioned this to the landlord, who said we should see how things develop when the weather gets warmer.
Best regards, bpe
Best regards, bpe
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