I have a question and I know the real answer is "it depends" but I was hoping to get some approximations in order to take a design decision. Basically, I have this cellar in Madrid now that has 71% relative humidity now after about 2 weeks of constant rain and atm it is autumn climate. Im renovating it as we speak doing doing impermibilization part by part and I am wondering now what kind of percentages I could expect during a more typical climate (I dont remember last time it was more than 3 days light raining here).
Question: About how much would 14 days of constant rain, no sunshine change the average humidity in Madrid? Month-average of october is 62% from a chart I have gotten.
Basically the basement is very old and beautiful brick without any waterproof membrane (its 100 years+) so I want to keep as much visible brick as possible for aesthetic but also economic reasons.
Btw, the volume is about 112 m3 and I have a dehumidifier of 20L/day that I am thinking about changing to a 50L/day dehumidifier. Would be interesting to get an estimate how that would affect humidity levels as well.
Non Sequitur
Oct 26, 16 1:21 pm
it depends
but seriously, hire a local professional. There are apparently 1000s of unemployed architects in spain and I sure the economy could use for of your spare cash.
Everyday Intern
Oct 26, 16 1:28 pm
Your question seems meteorological rather than architectural. You might try asking over here.
For figuring out how much moisture you need to remove from the air to decrease the relative humidity you could refer to a psychometric chart (the right side will show you increments for the amount of moisture in the air).
citizen
Oct 26, 16 3:06 pm
It's not the humidity, it's the heat...
Volunteer
Oct 26, 16 6:09 pm
In some climates you may need a humidifier in the winter and a dehumidifier in the summer, although air conditioning may often suffice for the summer. It is for occupant comfort and to prevent excessive drying out of the wood and structures on one hand or allowing mold to grow and water damage on the other. You really need to check with an expert in the field, especially if you are trying to preserve an older building. Get several opinions.
cgheintz
Nov 16, 16 11:00 am
Hi guys. I have done solutions to stop the source and now during winter I am at allright levels of humidity. I finally did some rebrushing on my psychonometric skills as post above and at the moment humidity is equivalent to 49-55% at 21 deg celsius which should be acceptable. However, now I have a different issue and thought id ask for the opinion. (I tightened the water seals and also added a more powerful ventilation system).
Lets say that with the extraction unit I could get down below 60% but after workhours humidity increases to 64-67% without rain. Is this a problem? I am asking because I am almost ready to move in, buy furniture etc but I do not want to do this unless the levels could be consider allright for a working environment (all year round, including rainer times). The ventilated drywall parititions and waterreppelant mortar all dust the place down like crazy.
awaiting_deletion
Nov 16, 16 8:44 pm
what temperature will your basement walls be at and how much below grade is your basement? in other words are the upper bricks exposed to the exterior?
Iololike
Nov 27, 16 12:51 am
I have no idea of it
gruen
Nov 27, 16 5:39 pm
In my basement-I run a small dehumidifier that drains to a sump pump. This keeps the humidity low in the summer months. It's not needed in the winter. Also a 100 year home. Not sure how many L/hour but it is fine for storage space.
Wood Guy
Nov 28, 16 12:06 pm
cgheintz, what you are trying to avoid is mold growth. There are many varieties but most go dormant when 1. The temperature is below ±50°F; 2. When the relative humidity is below 50-60%; or 3. When there is no food source. Mold spores are everywhere so don't think about killing them, just keep them dormant.
There is almost always a food source, so ignore #3.
In Madrid, the temperature is going to be above 50°F in almost all situations, even underground, so ignore #1.
The one item you have control over is the humidity level. Exactly what level is safe is hard to say, as mold varieties vary regionally, but 50% relative humidity (RH) is considered safe; 60% is getting into pretty risky territory. Above 60% RH you are asking for trouble.
If your building envelope is not tight, and especially if you are bringing in outside air with a ventilation system, you are continuously introducing moisture into the system. How sound is your building envelope, and what type of ventilation system do you have?
Hi!
I have a question and I know the real answer is "it depends" but I was hoping to get some approximations in order to take a design decision. Basically, I have this cellar in Madrid now that has 71% relative humidity now after about 2 weeks of constant rain and atm it is autumn climate. Im renovating it as we speak doing doing impermibilization part by part and I am wondering now what kind of percentages I could expect during a more typical climate (I dont remember last time it was more than 3 days light raining here).
Question: About how much would 14 days of constant rain, no sunshine change the average humidity in Madrid? Month-average of october is 62% from a chart I have gotten.
Basically the basement is very old and beautiful brick without any waterproof membrane (its 100 years+) so I want to keep as much visible brick as possible for aesthetic but also economic reasons.
Btw, the volume is about 112 m3 and I have a dehumidifier of 20L/day that I am thinking about changing to a 50L/day dehumidifier. Would be interesting to get an estimate how that would affect humidity levels as well.
it depends
but seriously, hire a local professional. There are apparently 1000s of unemployed architects in spain and I sure the economy could use for of your spare cash.
Your question seems meteorological rather than architectural. You might try asking over here.
For figuring out how much moisture you need to remove from the air to decrease the relative humidity you could refer to a psychometric chart (the right side will show you increments for the amount of moisture in the air).
It's not the humidity, it's the heat...
In some climates you may need a humidifier in the winter and a dehumidifier in the summer, although air conditioning may often suffice for the summer. It is for occupant comfort and to prevent excessive drying out of the wood and structures on one hand or allowing mold to grow and water damage on the other. You really need to check with an expert in the field, especially if you are trying to preserve an older building. Get several opinions.
Hi guys. I have done solutions to stop the source and now during winter I am at allright levels of humidity. I finally did some rebrushing on my psychonometric skills as post above and at the moment humidity is equivalent to 49-55% at 21 deg celsius which should be acceptable. However, now I have a different issue and thought id ask for the opinion. (I tightened the water seals and also added a more powerful ventilation system).
Lets say that with the extraction unit I could get down below 60% but after workhours humidity increases to 64-67% without rain. Is this a problem? I am asking because I am almost ready to move in, buy furniture etc but I do not want to do this unless the levels could be consider allright for a working environment (all year round, including rainer times). The ventilated drywall parititions and waterreppelant mortar all dust the place down like crazy.
what temperature will your basement walls be at and how much below grade is your basement? in other words are the upper bricks exposed to the exterior?
I have no idea of it
In my basement-I run a small dehumidifier that drains to a sump pump. This keeps the humidity low in the summer months. It's not needed in the winter. Also a 100 year home. Not sure how many L/hour but it is fine for storage space.
cgheintz, what you are trying to avoid is mold growth. There are many varieties but most go dormant when 1. The temperature is below ±50°F; 2. When the relative humidity is below 50-60%; or 3. When there is no food source. Mold spores are everywhere so don't think about killing them, just keep them dormant.
There is almost always a food source, so ignore #3.
In Madrid, the temperature is going to be above 50°F in almost all situations, even underground, so ignore #1.
The one item you have control over is the humidity level. Exactly what level is safe is hard to say, as mold varieties vary regionally, but 50% relative humidity (RH) is considered safe; 60% is getting into pretty risky territory. Above 60% RH you are asking for trouble.
If your building envelope is not tight, and especially if you are bringing in outside air with a ventilation system, you are continuously introducing moisture into the system. How sound is your building envelope, and what type of ventilation system do you have?