RH setting on dehumidifier / Mould killer on soft furnishings

[superheat6k]

I have recently placed a dehumidifier on board the boat to try to reduce mould forming on bedding and soft furnishings & bedding.

I have set the RH to 50% with the initial RH at 85%, and after a few days running and in very wet outside conditions today the RH was ~ 63%. The bedding felt dry so likely sufficient, and the 125w the unit uses ends up as background heat in the interior of the boat.

So what do others set the RH % to ?

I am conscious if it is set too low the wood can start to dry out and split.

I have sprayed the bedding with anti mould, but would patio magic be more effective on material cover mattresses ?

I can wash the loose bedding.

Thanks.

 

[[2574]]

Set our Meaco desiccant dehumidifier on “low” which results in 60% rh.

From leaving the boat unoccupied when lifted ashore it takes about ten days before the dehumidifier moves to a “maintenance“ state when it maintains 60%rh, power consumption stabilises at this time. No mould on board.

 

[VicS]

I have sprayed the bedding with anti mould, but would patio magic be more effective on material cover mattresses ?

I can wash the loose bedding.

Thanks.

Be sure not to use a chlorine bleach / hypochlorite based mould killer on fabrics. Use a benzalkonium chloride based one if necessary.
Patio Magic diluted 1 part with 9 parts water would be suitable .
Useful also for killing algae on running rigging etc although I use it diluted 1+4 for that

 

[iamtjc]

I certainly wouldn't want to sleep in bedding that had been dosed in benzalkonium chloride. Hand sanitisers may have in the order of 0.1 - 0.3% BAC. The concentrations suggested above would be concerning for long term skin contact. There are reports of pets being poisoned by contact with surfaces cleaned with BAC (see Toxicology section of wikipedia article on benzalkonium chloride).

 

[Sandy]

Why not take the soft furnishings off the boat and store them somewhere where is it dry?

 

[Elessar]

I have recently placed a dehumidifier on board the boat to try to reduce mould forming on bedding and soft furnishings & bedding.

I have set the RH to 50% with the initial RH at 85%, and after a few days running and in very wet outside conditions today the RH was ~ 63%. The bedding felt dry so likely sufficient, and the 125w the unit uses ends up as background heat in the interior of the boat.

So what do others set the RH % to ?

I am conscious if it is set too low the wood can start to dry out and split.

I have sprayed the bedding with anti mould, but would patio magic be more effective on material cover mattresses ?

I can wash the loose bedding.

Thanks.

I leave a desiccant dehumidifier running 24/7 for 4 or 5 months of the year on the low setting. Costs about £60/month in electricity.
I leave beds made to make the most of those lovely crisp winter days. The boat never has that cold to the bones feeling and I never have mould issues.
No idea what the RH is. I just leave it on low and it works with no issues.

 

[Elessar]

Why not take the soft furnishings off the boat and store them somewhere where is it dry?

Makes the boat too time consuming to use spontaneously. That's a waste of a boat.

 

[Momac]

As other shave said a Maeco DD8L on the lowest 'one drop' setting with the lowest fan speed does the job.

We have all bed sheets off the boat.
No need to spray anything .

 

[Aja]

Makes the boat too time consuming to use spontaneously. That's a waste of a boat.

Take a couple of sleeping bags from home for spontaneous visits

 

[Elessar]

Take a couple of sleeping bags from home for spontaneous visits

Why? I leave the beds made up all with cozy quilts and electric blankets.
And sandy said he takes the furniture home too so just a sleeping bag won’t do.
Why do some boaters think a hair shirt is necessary to enjoy the water?

 

[Bouba]

I use Lysol aerosol on everything

 

[johnphilip]

I have no idea of the actual % RH on board but I have used the same dehumidifier for over 10 years and no mould to date. I do adjust the machine based on my patented humidity test. A box of matches left in the galley drawer is the apparatus for the technology. If a match strikes easily first time the boat is dry enough.

 

[Halo]

I leave my Meaco on the two drops thumbs up setting. A stand alone RH meter shows that this maintains RH just below 50%. No sign of mould etc. I do take my boots home so they don’t dry out. No problem with woodwork and biscuits and crisps last forever. It takes a couple of
May try 1 drop setting.
Meter below is ideal imho
https://www.amazon.co.uk/ThermoPro-...5&psc=1&mcid=7a5fe5755c9738efb6b1c7ffc3043811

 

[jdc]

This is the humidity / temperature scatter plot for my boat over the the last 30 days. The dehumidifier runs at around 52%RH most of the time, with occasional forays a bit higher, usually when I'm doing some work on board and so have the hatches open.

It's a setting which over several years I've found to give a good environment; the bedding and fabrics stay dry yet the wood work doesn't dry out excessively. No smell of damp in any cupboard either.

 

[Halo]

This is the humidity / temperature scatter plot for my boat over the the last 30 days. The dehumidifier runs at around 52%RH most of the time, with occasional forays a bit higher, usually when I'm doing some work on board and so have the hatches open.

It's a setting which over several years I've found to give a good environment; the bedding and fabrics stay dry yet the wood work doesn't dry out excessively. No smell of damp in any cupboard either.


View attachment 169070

Interesting colour chart. It shows 60% humidity is good up 15 degrees. If so I can turn my dehumidifier down! What is the source please?

 

[Halo]

Found another chart

 

[Dellquay13]

Found another chart

View attachment 169096

Interesting for homes, but the temperature inside a boat in winter isn’t usually kept so high

 

[jdc]

Well, it's hotter in Australia! My chart I made myself (+ point: it uses growth rates to determine colour rather than just a 'zone', - point: it's 'home made').

See for instance this url for the science. I used Matlab as the computing and plotting language. The Australian Asthma society plot is the older graphic, but the one that prompted me to try to make a more nuanced version for myself.

 

[MikeBz]

This is the humidity / temperature scatter plot for my boat over the the last 30 days. The dehumidifier runs at around 52%RH most of the time, with occasional forays a bit higher, usually when I'm doing some work on board and so have the hatches open.

Do you know roughly how many hours a day it runs in order to achieve that? Just curious.

 

[[2574]]

Do you know roughly how many hours a day it runs in order to achieve that? Just curious.

This might help - a Meaco DD3L desiccant dehumidifier has used about 1.4kwh in in the last 24hr, cycling visible in this graph showing power drawn from shore:



Here is the environmental sensor report for the same period: