tim
Well-Known Member
Hi,
Has anyone tried out a 12v dehumidifier? Any idea how many amps they need.
Thanks,
Tim
Has anyone tried out a 12v dehumidifier? Any idea how many amps they need.
Thanks,
Tim
12v Dehumidifiers
- Thread starter tim
- Start date
abraxus
Well-Known Member
Why would want one? You would need a 240v supply to keep the batteries charged to run it, so why not just a get a 240v one.
The only advantage I can see is size, but this also is usually their downfall as the really small ones dont extract much moisture.
If you dont like the usually bulky 240v ones then the £75 one B&Q is very good. Smaller than most (about 18" high), but bigger and more powerful than than useless little compact one.
I've had one for two years and am very impressed with it.
The only advantage I can see is size, but this also is usually their downfall as the really small ones dont extract much moisture.
If you dont like the usually bulky 240v ones then the £75 one B&Q is very good. Smaller than most (about 18" high), but bigger and more powerful than than useless little compact one.
I've had one for two years and am very impressed with it.
simonfraser
Well-Known Member
great question, how many solar / wind systems does one need ?
Rivers & creeks
Well-Known Member
They use approx 5amps and extract between 250ml and 500ml in 24 hours. That's about one twentieth the performance of a 240V one. Better to get the 240v model and run it either from shore power or via an inverter (the B&Q ones draw 200W) when the engine is running.
tim
Well-Known Member
My boat is lifted out for the winter, but I don't have any mains nearby. However, I do have 330 amphours and a Rutland 913. I presume that they switch of once full, in which case the batteries will have plenty of time to recover. Anything is better than nothing.
abraxus
Well-Known Member
Oh, I see Tim
Well as I said they aren't that great. They will shut off when full or with some you can attach pipe for continuos drainage into the sink.
If you're going to let it shut off when full, then it would probably only be of use if you were able to empty it out every day, or every other day.
My guess is that unless you could run a dehumudifier off the mains, with a continual drain into a sink, then you may just be better off without it and make sure you have good ventilation instead.
Well as I said they aren't that great. They will shut off when full or with some you can attach pipe for continuos drainage into the sink.
If you're going to let it shut off when full, then it would probably only be of use if you were able to empty it out every day, or every other day.
My guess is that unless you could run a dehumudifier off the mains, with a continual drain into a sink, then you may just be better off without it and make sure you have good ventilation instead.
simonfraser
Well-Known Member
why not pump it out with a small bilge pump on a float switch ?
p.s. pasta simon
5 amp hours x 24 or 5 amp per 24 hrs ??????
p.s. pasta simon
5 amp hours x 24 or 5 amp per 24 hrs ??????
abraxus
Well-Known Member
No need, could just drain direct to sink for continuous operation. I was assuming however that he wanted to let it fill it's container and stop automatically as a means of switching it off to preserve battery power.
DaveS
Well-Known Member
pasta_simon's statement re. current was unambiguous as stated. Current is measured in amperes (A). Current X time gives ampere-hours (Ah). Drawing 5A for 24h will consume 120 Ah. (Probably less in practice - no account taken of humidistat action, "full tank" switch, etc.)
There is a lot of misunderstanding about this, not helped by use of incorrect terminology such as "amps per hour". You even see this sort of nonsense perpetrated in supposedly technical articles in yachty magazines.
There is a lot of misunderstanding about this, not helped by use of incorrect terminology such as "amps per hour". You even see this sort of nonsense perpetrated in supposedly technical articles in yachty magazines.
malcp
Well-Known Member
Another option is to use the anhydrous crystal and pot based dehumidifiers. These can be left for a couple of weeks without needing to be emptied (depending on size), and although are not as effective as an electric one do work sufficiently to keep the moisture under control. I normally use 4 spread out evenly in a 35ft boat, and they work well enough.
Just a thought.
Just a thought.
AvanLoon
Active Member
As a coincidence, I looked at at 12V dehumidifier this afternoon in a drugstore in the Netherlands. Price was good enough: €40, so about GBP 30. It draws 3A at 12V, so the energy consumption is very low.
It runs on a Peltier element, but I saw in the documentation it runs best in a realtive humidity from 50% and 15 deg Celsius. Not exactly the circumstances for a winter lay up. I still have my doubts.
Kind regards
It runs on a Peltier element, but I saw in the documentation it runs best in a realtive humidity from 50% and 15 deg Celsius. Not exactly the circumstances for a winter lay up. I still have my doubts.
Kind regards
pvb
Well-Known Member
Thought about ventilation?
Most people find that adequate ventilation works perfectly on a boat. The recent boom in sales of domestic dehumidifiers is undoubtedly the result of more effective home insulation (ie no draughts through window frames).
Most people find that adequate ventilation works perfectly on a boat. The recent boom in sales of domestic dehumidifiers is undoubtedly the result of more effective home insulation (ie no draughts through window frames).
ShipsWoofy
Well-Known Member
[ QUOTE ]
Why would want one? You would need a 240v supply to keep the batteries charged to run it, so why not just a get a 240v one.
[/ QUOTE ]
And nobody sails anywhere but the Solent and has a marina berth with telephone, electricity and moving walkways........
Come on Abrax, think a little /forums/images/graemlins/grin.gif
I too noticed the article, in YM and wondered, they said 5A maximum, what ever that means, does it generally sit at 1A and go up and down. YM are testing them next month, a little late in the season really, but alas!
EDIT>> duh! should have read down the page before replying, not all of us on the moorings are manky ol' filthy boats ya know!
Why would want one? You would need a 240v supply to keep the batteries charged to run it, so why not just a get a 240v one.
[/ QUOTE ]
And nobody sails anywhere but the Solent and has a marina berth with telephone, electricity and moving walkways........
Come on Abrax, think a little /forums/images/graemlins/grin.gif
I too noticed the article, in YM and wondered, they said 5A maximum, what ever that means, does it generally sit at 1A and go up and down. YM are testing them next month, a little late in the season really, but alas!
EDIT>> duh! should have read down the page before replying, not all of us on the moorings are manky ol' filthy boats ya know!
ShipsWoofy
Well-Known Member
Re: Thought about ventilation?
[ QUOTE ]
Most people find that adequate ventilation works perfectly on a boat. The recent boom in sales of domestic dehumidifiers is undoubtedly the result of more effective home insulation (ie no draughts through window frames).
[/ QUOTE ]
Good point, when I did a few stints labouring when I was a student one job I had was cutting loads of holes in the eves of a new house and adding vents as it failed its survey.
I guess double sealed glazing and super efficient front and back doors are going to play havoc, I often have a window open ajar when the heating is on so I can breathe, but I think a lot of that comes from being boaty, I really hate being shut in!
[ QUOTE ]
Most people find that adequate ventilation works perfectly on a boat. The recent boom in sales of domestic dehumidifiers is undoubtedly the result of more effective home insulation (ie no draughts through window frames).
[/ QUOTE ]
Good point, when I did a few stints labouring when I was a student one job I had was cutting loads of holes in the eves of a new house and adding vents as it failed its survey.
I guess double sealed glazing and super efficient front and back doors are going to play havoc, I often have a window open ajar when the heating is on so I can breathe, but I think a lot of that comes from being boaty, I really hate being shut in!
BrendanS
Well-Known Member
Pure physics says that crystal based dehumidifiers in a large boat are a waste of time, though the psychological probably says it's doing something.
Crystal based dehumidifiers are only suited to very small enclosed areas like cupboards
A well vented boat will stay drier than a closed in boat with crystal absorption. A combination of both is a complete waste of time.
Crystal based dehumidifiers are only suited to very small enclosed areas like cupboards
A well vented boat will stay drier than a closed in boat with crystal absorption. A combination of both is a complete waste of time.
abraxus
Well-Known Member
[ QUOTE ]
And nobody sails anywhere but the Solent and has a marina berth with telephone, electricity and moving walkways........
Come on Abrax, think a little
[/ QUOTE ]
Fair enough Woofy, I was however thinking that without mains electricity then there would be the issue of charging the batteries. I am shocked though, doesn't everyone have moving walkways? /forums/images/graemlins/smirk.gif
That being said, battery charging is available so I would still be tempted by a 240v dehumidifier run off an inverter and draining into the sink.
This again is because the only 12v ones I've seen are quite small and not very powerful and not much better than the crystals.
And nobody sails anywhere but the Solent and has a marina berth with telephone, electricity and moving walkways........
Come on Abrax, think a little
[/ QUOTE ]
Fair enough Woofy, I was however thinking that without mains electricity then there would be the issue of charging the batteries. I am shocked though, doesn't everyone have moving walkways? /forums/images/graemlins/smirk.gif
That being said, battery charging is available so I would still be tempted by a 240v dehumidifier run off an inverter and draining into the sink.
This again is because the only 12v ones I've seen are quite small and not very powerful and not much better than the crystals.
ChunkyMonkey
New Member
There is another valid use for 12v dehumidifiers: I am just building a bigger solar panel for my boat, and need a dump load for the charge regulator. I can't find a suitable 12v fan heater, so thought a dehumidifier might be a useful way of using the power.
There's always more than one end to a problem...
Any ideas of a beneficial use of about 60W?
There's always more than one end to a problem...
Any ideas of a beneficial use of about 60W?
