Dehumidifiers

[Keiron]

After a cheap dehumidifier for a 23' sailing boat. Anyone have any suggestions. I also have a problem regarding what to do with the waste water. I don't have a plumbed in sink... Any suggestions. I presume the drain pipe needs to be lower than the waste on the unit?

 

[FAITIRA]

K, Run the drain into a 5gal container on the sole, dehumid on the table, should b ok for weeks in a boat that size.

 

[Aja]

Nope. Won't work unless you seal the contents of the 5 gal drum from the rest of the atmosphere.

All you would do is re-circulate the humidity. A great waste of the earth's resources.

Donald

 

[Strathglass]

Just bought one from B&Q it was reduced to about £50.

When it is heavy rain it fills the in built container in less than a day.

When draining it externally the outlet pipe (any 1/2" pipe)must slope downwards from the drainhole.

I now have mine draining through the sink drain.

It would be possible to sit it on a box and let it drain in to a bucket with a lid and input hole but, once the bucket was full it would not stop outputing water.

I recon you would have to plan on at least weekly visits in wet conditions if you did this with it set quite high.

Iain

 

[DaveS]

If you have a paddle wheel log you could take out the transducer and stick the condensate pipe down the hole.

 

[sarabande]

on the basis that the dehumdingifier would be outputting more than the sea is inputting ? /forums/images/graemlins/grin.gif

 

[FAITIRA]

If you are filling a 5 gal drum in a month you have one incredible damp problem.

 

[Aja]

For all of the above suggestions, all your humidifier is doing is removing damp from the atmosphere. It will not be removing damp from the boat.

To remove damp from the boat the boat has to be sealed from the atmosphere and the water collected ejected to outside the sealed boat. So it can't get back in.

The amount of water drained this way will - over time diminish. It doesn't matter if it rains for forty days and forty nights, the amount of water inside will diminish.

Donald

 

[sarabande]

'Taint necessarily so !

Depends on the internal volume of boat, how much natural ventilation there is (replenishes the water vapour content), size of the condenser, hours run, the required air temp and rel hum set on the controls, frinstance.

Mine can easily produce 3 litres in a day when it's working hard (35ft boat, 2.5kW heater/humidifier) and the conditions are right.

 

[gandy]

Draining into a container will work. Re-evaporation from the container won't be significant compared to the work of the dehumidifier. The same applies for dehumidifiers with built-in collection tanks.

 

[Kylora]

I bought the B&Q one a couple of years ago. Works fine. You don't need to have the humidistat set very high.
I use it with the built in container and float switch at the beginning and end of the season. I plumb it in during the winter.
I have it sitting on a container to gain height, and the hose runs through into a cockpit locker where it is teed into a hose which drains the cockpit seat. I don't like to leave the sink drain seacock open.
I find that the small rubber plug which you remove from the hose connection needs to be pushed up into the hole where the water falls into the built in container. Even then the container does fill up very slowly, and the float switch will switch the unit off if not checked every 4 - 6 weeks. Tilting the unit slighty towards the hose might help.

Ash

 

[FAITIRA]

Well explained!

 

[shmoo]

Draining into a container will work for following reasons. You are trying to remove moisture from the air, and from bulkheads, fabric and so on. Moisture in air is already gaseous and so only needs to be condenced. Moisture on bulkheads etc has very large surface area, tens of sq meters and wll evaporate easily into (the now drier) air. The latent heat of evaporation being supplied through the hull by the sea. The situation inside the container is different. Small surface area and only source of latent heat of evaporation through (again small) outside surface of container and surounding air (not much heat in air).

Otherwise do what we do and stand dehumidifer in the sink (with plug out)

 

[Rivers & creeks]

Appologies that this is a repeat of an earlier post, but it worked so darn well for me I'll offer it again - I have one of the B&Q jobbies but I found it difficult to get the auto drain function to work, and tilting it without it falling over was awkward. So I drilled a small hole 3/4 of the way up the tank, put a brass spiggot in and ran 1m of hose to the sink (our outlet is above the water line). Can now run continuously without being tilted or leaking.

 

[Habebty]

Another option obviously with the boat laid up out of the water is to remove the log paddlewheel and stick the hose from the dehumidifier down the resultant hole ! (wrap some duck tape around the hose up to the diameter of the log aperture) Then seal up the boat with no or minimal ventilation or you will be trying to dehumidify England.

 

[Kylora]

I have considered doing the same thing, but was worried in case I cracked the container.
Advantages
Able to create a couple of inches WG pressure head on the hose.
The float cut off switch can still operate if something happens to the hose - ie freezes.
Could be coupled to a larger capacity container ( top above the level of the float switch) if not plumbed in.

Think I might try it after the winter.

BTW - Does anyone know if you can buy replacement containers - if the worst was to happen.

Ash

 

[Tomkat17]

It always amazes me how often people don't answer the question asked. I bought a dehumidifier GDNM10A4BK4AA from B&Q which you can either use the front tank for collecting the water or connect the hose provided to the rear of the machine for continuous draining.
The other benefit is that it does not have an on/off switch which means that if the power supply is interupted you don't have to manually reset. Given the issues you can get on a marina supply this is very useful. It also has a variable setting which allows you to control the level of power it uses each day which controls the cost.