I was looking at the thermometer in the cellar. Was 74% humidity. I put a different one in and got 68. I seem to remember the cellar one reading high when I charged the battery.
Outside is 83% at 15°. This calculates to 10.63g/m2 absoulute humidity, using an online calculator. Cellar is 19.5°. At 10.63 it should be 63° relative humidity on the thermometer. So it's 5% over. Not massive, but enough to keep an eye on. It has been raining a lot recently.
I'll keep an eye on it. If necessary, I'll buy another Meaco dehumidifier, and just run it for a few hours whenever necessary.
Lodger's room above was a bit damp, but I think that was mainly from him hardly ever opening his window. I can leave his trickle vent open now the room's empty. I have the window open now.
I use the same calculation for the attic, and put all the results on a spreadsheet for future reference. Currently attic is 2% lower than calculated value.
Damp
Re: Damp
Sorry, maybe this should be under 'how are you preparing'. The website with the calculator is https://www.omnicalculator.com/physics/ ... e-humidity
They also have a separate one for dew point, which I'll use for attic in colder weather. Trying to avoid condensation.
So we are obtaining the ABSOLUTE humidity for outside, and usiing that and the temperature inside to see what the relative humidity (shown on the digital thermometer which transmits to my phone) inside the attic and cellar.
They also have a separate one for dew point, which I'll use for attic in colder weather. Trying to avoid condensation.
So we are obtaining the ABSOLUTE humidity for outside, and usiing that and the temperature inside to see what the relative humidity (shown on the digital thermometer which transmits to my phone) inside the attic and cellar.
Re: Damp
Reading on the second thermometer crept up to 70% and it was only 50% outside. Allowing for temperature difference it should be 60 in the cellar, so I bit the bullet, and ordered a dehumidifier. It's a Meaco ABC 10, same as I have on the landing. If I run it for 10 hours, it should cost about 35p. Or I can just leave it a few days, then switch off when full. They are a bit noisy though, so if I got another lodger in the room above, I might have to switch it off at night. I might be able to use it with a timer plug like I have for my lamps.
-
Yorkshire Andy
- Posts: 9888
- Joined: Thu Oct 03, 2013 4:06 pm
Re: Damp
How this fits into intel articles ill never know
If your roughing it, Your doing it wrong 
Lack of planning on your part doesn't make it an emergency on mine
Lack of planning on your part doesn't make it an emergency on mine
Re: Damp
That's why I said sorry I probably should have posted in 'how are you preparing'. But it does have a link and a method for calculating what the humidity should be in a room, relative to humidity outside.
Re: Damp
Dehumidifier arrived. Cellar is 71-72% humidity. It's actually not bad considering it's 81% outside, and only about 1° cooler. But I thought I might as well run it for a few hours and see how much it drops. Living room is 57.5%, which isn't too bad considering the weather. Ideal is 50%, with a range of 40-60%.
Only snag is my electricity use has doubled, maybe more. It's been about 100kW/h, occasionally 200 when the fridge compressor runs. It's 240 at the moment, was 340 for a while earlier, I guess that was the fridge. So it uses about 150 w/h. They quote 165 so it's about right.
Part of the cellar window actually has no glass, but I put plastic sheet over it. I should have opened it up a bit in the summer, to air the cellar.
Only snag is my electricity use has doubled, maybe more. It's been about 100kW/h, occasionally 200 when the fridge compressor runs. It's 240 at the moment, was 340 for a while earlier, I guess that was the fridge. So it uses about 150 w/h. They quote 165 so it's about right.
Part of the cellar window actually has no glass, but I put plastic sheet over it. I should have opened it up a bit in the summer, to air the cellar.
Re: Damp
Reasons I think damp/humidity in a house is of relevance to preppers.
Damp and humidity in a house is a relevant issue for preppers and it's often overlooked in favour of more dramatic risks. Here's why it's important:
Why Damp and Humidity Matter for Preppers:
1. Threat to Long-Term Food Storage
High humidity compromises shelf-stable foods like grains, pasta, powdered milk, etc.
Moisture encourages mold growth, oxidation, and spoilage, even in sealed containers if not properly stored.
It can also affect vacuum-sealed or Mylar bagged goods if desiccants aren't used.
2. Compromises Equipment and Supplies
Humidity causes rust on tools and electronics.
Batteries degrade faster in high humidity.
Fire-starting materials like matches or tinder can become useless.
3. Encourages Mold and Mildew
Mold in walls, insulation, or furniture can cause health issues - especially respiratory problems.
In a long-term survival situation, access to medical care for mold-related illness may be limited.
4. Structural Damage
Damp can rot timbers, weaken walls, and degrade insulation—compromising your shelter.
In extreme cases, this could make a bug-in location unsafe or uninhabitable.
5. Pests
Moist environments attract many different pests in the UK some or all of which can destroy food stores and damage infrastructure. Pests that damp can attract range from mice and rats, cockroaches, woodlice, earwigs, moths, drainflies, fungus gnats, ants, fungus beetles, mould mites, and silverfish.
Prepper Strategies to Combat Damp:
Use desiccants (like silica gel or bentonite clay) in storage containers.
Seal food in Mylar bags with oxygen absorbers and store in dry, cool areas.
Install dehumidifiers or ventilation in basements and storage areas.
Regularly inspect for leaks in roofs, pipes, and around windows.
Store gear in sealed plastic bins or waterproof containers.
Monitor humidity levels with a hygrometer - aim for <50% in most areas.
Humidity is a slow, silent threat - but in a long-term grid-down or off-grid scenario, it can destroy food, gear, shelter, and health. It’s absolutely relevant to preparedness.
Damp and humidity in a house is a relevant issue for preppers and it's often overlooked in favour of more dramatic risks. Here's why it's important:
Why Damp and Humidity Matter for Preppers:
1. Threat to Long-Term Food Storage
High humidity compromises shelf-stable foods like grains, pasta, powdered milk, etc.
Moisture encourages mold growth, oxidation, and spoilage, even in sealed containers if not properly stored.
It can also affect vacuum-sealed or Mylar bagged goods if desiccants aren't used.
2. Compromises Equipment and Supplies
Humidity causes rust on tools and electronics.
Batteries degrade faster in high humidity.
Fire-starting materials like matches or tinder can become useless.
3. Encourages Mold and Mildew
Mold in walls, insulation, or furniture can cause health issues - especially respiratory problems.
In a long-term survival situation, access to medical care for mold-related illness may be limited.
4. Structural Damage
Damp can rot timbers, weaken walls, and degrade insulation—compromising your shelter.
In extreme cases, this could make a bug-in location unsafe or uninhabitable.
5. Pests
Moist environments attract many different pests in the UK some or all of which can destroy food stores and damage infrastructure. Pests that damp can attract range from mice and rats, cockroaches, woodlice, earwigs, moths, drainflies, fungus gnats, ants, fungus beetles, mould mites, and silverfish.
Prepper Strategies to Combat Damp:
Use desiccants (like silica gel or bentonite clay) in storage containers.
Seal food in Mylar bags with oxygen absorbers and store in dry, cool areas.
Install dehumidifiers or ventilation in basements and storage areas.
Regularly inspect for leaks in roofs, pipes, and around windows.
Store gear in sealed plastic bins or waterproof containers.
Monitor humidity levels with a hygrometer - aim for <50% in most areas.
Humidity is a slow, silent threat - but in a long-term grid-down or off-grid scenario, it can destroy food, gear, shelter, and health. It’s absolutely relevant to preparedness.
Re: Damp
A dehumidifier won't help with the cause though, good ventilation and ideally where budgets allow use breathable paints & mortars in cellars.
We have a C16 place with cellars and fitted several low energy fans which circulate the airflow through the rooms and out and it has made a huge improvement, prior to that we had two dehumidifiers running constant (i hooked them up to condensate pumps to extract the moisture), the electric cost was considerable.
Are there two possible airflow directions in your cellar @frnc if so i'd personally look at having a small fan for intake and one for extract. Far far cheaper to run and maintain.
We have a C16 place with cellars and fitted several low energy fans which circulate the airflow through the rooms and out and it has made a huge improvement, prior to that we had two dehumidifiers running constant (i hooked them up to condensate pumps to extract the moisture), the electric cost was considerable.
Are there two possible airflow directions in your cellar @frnc if so i'd personally look at having a small fan for intake and one for extract. Far far cheaper to run and maintain.