Controlling humidity in cellar

[Cellarman]

A tale as old as time…

I’ve found some similar posts, but with conflicting information.

I have a cellar in a Victorian property. There’s a few original features that are blocked up - coal hole, chimney. There’s slight water ingress through the coal hole that needs addressing.

Anyway, I’m confused by the different options to keep humidity under control in the long term.

- Is a dehumidifier pointless? I saw someone compare it to trying to move forward when running on a treadmill. I have a basic one down there right now but it needs running (and emptying) daily. But it does reduce RH from around 85 to 55. So this would be a full time operation.
- I understand the most important thing is airflow. But from where, to where? Do I want to draw in external air? Do I want to just vent out stale air and draw air in from the rest of the house?
- How about typical split air con units? Could this help solve the problem?

Appreciate your thoughts!

 

[CuriousInk]

Hey Cellarman!

We've just moved into our Victorian property and encountered the same issues as you when trying to understand ventilation.
Background; Our survey says the ventilation is inadequate in our cellar as our chutes have been blocked up and the air bricks are too small. It's very damp down there. You can see that the joists have been replaced; there is wet rot; it's not pretty. (There also might be a problem for us with drainage getting into the cellar, but we're taking it one step at a time)

My understanding is that the air in the cellar needs to be changed four times in an hour to replace humid, stale air with fresh, dry air.

- I'm waiting on a consultation with Vapour Flow (Products I linked below) about their ventilation system but it seems like something we're definitely going to do (consultation costs £100); https://www.vapourflow.com/

Based on my understanding (just pooling all the information I've read):

1. An additional dehumidifier running with a ventilation system in the cellar won't be needed; the dehumidifier is basically sucking on an unlimited supply of water from the walls and isn't helping to ventilate/change the air, so it won't be as effective or efficient as ventilation to keep things dry. The ventilation system will move fresh, dry air in from outside of the property (taken in from unit 1 in the cellar) and pick up moisture on its way out (pushed back outside from unit 2)- these units can work in tandem to adapt to the changing conditions in the house and outside the house (it has a humidistat) to make sure air in the cellar/house is in the ideal condition. When the temperature drops outside, it will also heat the air blown in to stop condensation from occurring.

I think this method is called 'Positive Input Ventilation'?

Unit 1 https://www.vapourflow.com/product/wad-warm-air-dehumidifier-fan-attic-whole-house/
Unit 2 https://www.vapourflow.com/product/dryvent-inline-bathroom-extractor-fan/

2. Where to place the units: I hope to figure this out with my consultation with VapourFlow, but I'm assuming it will be from the coal chute and elsewhere in the house (eg. the other inside the basement or the kitchen?)

3. Not sure about this one!

Here is also a video explaining how the system works:

Hope this can help and I'll let you know how I get on

 

[Cellarman]

Thanks @CuriousInk! Please keep us updated with your progress.

I have watched the Peter Ward videos before (twice earlier this evening!!). There’s just one thing I find slightly confusing - he talks about the two machines creating a ‘flow’. Given this, I’d expect one machine to let fresh air in, and the other side to expel stale air - so there’s a continuous current. It actually seems not to work this way - instead they both do the same thing at each end of the building. I don’t doubt this is successful as the humidistat is smart enough to know if to draw in air or expel it, but it has added to my confusion.

 

[ThornhillMike]

Thanks @CuriousInk! Please keep us updated with your progress.

I have watched the Peter Ward videos before (twice earlier this evening!!). There’s just one thing I find slightly confusing - he talks about the two machines creating a ‘flow’. Given this, I’d expect one machine to let fresh air in, and the other side to expel stale air - so there’s a continuous current. It actually seems not to work this way - instead they both do the same thing at each end of the building. I don’t doubt this is successful as the humidistat is smart enough to know if to draw in air or expel it, but it has added to my confusion.

Is the theory not that each unit is drawing warm/dry air from within the house whilst expelling damp(er) air outside. The warm air drawn through naturally circulates around the damp room as a result?

 

[trunky]

I remember Peter Ward, used to go mining with him in the 80's, what a small world.