Dehumidifier

[AKULA]

Would there be any benefit to me running one for a week

[nicknorman]

Cryptic! Benefit for what - ie what is the problem you are trying to address. And are you on shore power?

 

Over the winter, on an unheated boat, they are good, keep damp and mould at bay, stop wood swelling. But by this time of year I would have thought good ventilation would be nearly as effective and of course free. If you do go for a dehumidifier, and assuming you are not on the boat, close all windows and maybe block the vents. You are trying to take the humidity out of the air in your boat, not all the air outside your boat!

 

If you are on battery power, don't even think about it!

[Grace and Favour]

Would there be any benefit to me running one for a week

They cost less to run per hour than a narrowboat - - will you be using it for work (commuting) or just for short trips at weekends??

 

Edited April 24, 2014 by Grace & Favour

[davidc]

I run a dehumidifier on monty in winter it was every night now I'm down to once a week for 4 hours and I still get about 2 to 3 pints of water.

[ditchcrawler]

I run a dehumidifier on monty in winter it was every night now I'm down to once a week for 4 hours and I still get about 2 to 3 pints of water.

If you have the prescribed amount of fixed ventilation you will, you will be trying to dry the world.

[Psycloud]

If you have the prescribed amount of fixed ventilation you will, you will be trying to dry the world.

To some extent, but even without blocking up the vents our dehumidifier will drop humidity from 90% down to 55% during the cold months with 3 or 4 adults sleeping in the back half of the boat (with the door shut) and this makes a big difference to the condensation. We also pull a couple Litres of a nighttime. I wouldn't want to run it away from shore power though.

Edited April 24, 2014 by Psycloud

[nicknorman]

I guess it depends on the wind etc but the first winter we had the dehumidifier (on whilst we were away from the boat) we closed the windows but left the vents. It got the humidity down to 50%. The second winter I started taping up the vents when we left the boat. The dehumidifier still got the humidity down to 50% but it used noticably less electricity in doing so.

[bottle]

Would there be any benefit to me running one for a week

 

I am guessing that you have come back to the boat and it is damp.

 

In that case, if you have shorline then yes or light the fire, put on the heating and ventilate, ventilate and finally ventilate.

[geoffwales]

Refrigerant dehumidification will work at its most efficiently above 12c, below this use a dessicant dehumidifier. If you are putting heat on then try and use an electric type heater as fossil base fuels ie wood coal release up to .8 ltr of moisture per kg burnt back into the atmosphere when burning. So you may transfer energy/heat into the boat to evaporate moisture but unless its well ventilated younwill also increase the RH and moisture content.

 

So in short, yes plenty of heat and ventilation or dehumidifier and close all the windows. Also if you do buy a dehumidifier try and get one with a gravity drain and place the dh on the kitchen draining board so the condensate drain drips away down the plug hole, this saves emptying it or it switching off once full.

Edited April 25, 2014 by geoffwales

[nicknorman]

If you are putting heat on then try and use an electric type heater as fossil base fuels ie wood coal release up to .8 ltr of moisture per kg burnt back into the atmosphere when burning. So you may transfer energy/heat into the boat to evaporate moisture but unless its well ventilated younwill also increase the RH and moisture content.

 

 

Erm... NO!

 

Not unless your coal stove has no flue and puts all its combustion products into the cabin, in which case a bit of humidity would be the least of your worries! It is of course true that burning fossil fuels creates water vapour, but this is discharged via the flue outside. A coal or wood stove is one of the best ways of ensuring a cosy dry boat, in part due to the MOISTURE-FREE HEAT and also because the draw of the stove helps the ventilation.

[geoffwales]

Erm... NO!

 

Not unless your coal stove has no flue and puts all its combustion products into the cabin, in which case a bit of humidity would be the least of your worries! It is of course true that burning fossil fuels creates water vapour, but this is discharged via the flue outside. A coal or wood stove is one of the best ways of ensuring a cosy dry boat, in part due to the MOISTURE-FREE HEAT and also because the draw of the stove helps the ventilation.

Disagree in part, whilst a reasonable percentage will be flued away, once the fire has cooled down the atmosphere will as well, which means that the air surrounding that has been increased in temperature will cool down and the moisture trapped as a gas will revert to condensate on windows and colder surfaces. As i said i dont disagree that heating will help, keeping fire stoked 24hrs a day even when unattended i think would be difficult. Therefore i would recommend a dehumidifier.

[nicknorman]

Disagree in part, whilst a reasonable percentage will be flued away, once the fire has cooled down the atmosphere will as well, which means that the air surrounding that has been increased in temperature will cool down and the moisture trapped as a gas will revert to condensate on windows and colder surfaces. As i said i dont disagree that heating will help, keeping fire stoked 24hrs a day even when unattended i think would be difficult. Therefore i would recommend a dehumidifier.

All the flue gases will be flued away, otherwise the stove would kill you. Of course when the stove goes out, its effect is lost. It's not magic! And yes, the stove acts by reducing the relative humidity not the absolute humidity, but it is RH that is relevant for all practical purposes.

 

So if you need to keep the RH down below ambient in a cold boat, then the dehumidifier is the way to do it. If you want to keep it below ambient in an occupied boat, a stove is the way to do it because presumably you want warmth as well as dryness.

 

That burning coal or wood produces water vapour, as per your original post, is completely irrelevant because it is all sent outside. That is the main thrust of my disagreement.

Edited April 25, 2014 by nicknorman

[geoffwales]

All the flue gases will be flued away, otherwise the stove would kill you. Of course when the stove goes out, its effect is lost. It's not magic! And yes, the stove acts by reducing the relative humidity not the absolute humidity, but it is RH that is relevant for all practical purposes.

So if you need to keep the RH down below ambient in a cold boat, then the humidifier is the way to do it. If you want to keep it below ambient in an occupied boat, a stove is the way to do it because presumably you want warmth as well as dryness.

That burning coal or wood produces water vapour, as per your original post, is completely irrelevant because it is all sent outside. That is the main thrust of my disagreement.

I have my opinion you yours !

[nicknorman]

I have my opinion you yours !

Opinions are one thing, as you say we are each entitled to our own. But you were not stating an opinion, you were stating facts. False facts.

Edited April 25, 2014 by nicknorman

[geoffwales]

As

Opinions are one thing, as you say we are each entitled to our own. But you were not stating an opinion, you were stating facts. False facts.

Its DEhumidifier not humidifier

[johnmck]

We are summer cruisers, with the boat being laid up over winter. In late Autumn, we drain down the water system and remove filters, shower mixers and leave the boat unheated but well ventilated.

 

In spring, we reverse the process and as the weather warms, close the vents/windows and use dehumidifier.( Before we move onboard ) We did this over last weekend and the boat is now well aired out. We will continue to make use of the dehumidifier untill we leave the marina. Normally we would be out by now, but my new knee has delayed the off.

 

My thinking is, unless you heat the boat 24/7 over winter, when is goes off you will get condensation. Hence we have no heat on but good ventilation. The worst we get is a few wardrobe doors and drawers sticking, but with a dry bilge. A few days use of the dehumidifier prior to moving onboard in spring, soon sorts this out.

 

Works for us...

[nicknorman]

As

 

Its DEhumidifier not humidifier

Thank you, that was a typo, I've now corrected it.

[geoffwales]

Thank you, that was a typo, I've now corrected it.

Your welcome, i do appreciate your point

[Grace and Favour]

It's possible that Akula is busy baling out his condensation with a bucket - - he's not been back to read up on anyone's advice :0

[nicknorman]

It's possible that Akula is busy baling out his condensation with a bucket - - he's not been back to read up on anyone's advice :0

 

I must acquire some more secret duplicate IDs. Think of the fun starting a one-liner topic and then sitting back watching the bickering unfold!

[AKULA]

Bin in Walton hospital all day had a stroke while back so can to check head I was thinkin it would pull moisture from in seen under the floor I have 18 porthes all double glazed so was more for me about the out of site moisture I've an ebac powerdri I've 1200 amps avail and 600 watts of solar I was thinking stand it in the sink and leave it on but other than that no probs really enjoyed all you're posts though sorry about spelling and punctuation am on a phone and struggling lol. Best whishes all happy happy happy doo laly