I was wondering if 110V dehumidifiers are used on board while at the marina, and if so, how effective are they? I remember when I was a kid in Minnesota we always ran one in the house during the summer. I'm assuming that they still have the water collection pan that needs to be emptied all the time, otherwise the float raises up and turns the system off. I was thinking that it could be plumbed so that it drains out an above water line thru hull. Do you think that this would help keep the musty, dampness out of linen, clothes, paper, etc? Thanks, Jeff
Dehumidifier on board
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Using a Dehumidifyer. Anyone use a space heater?
I use a small dehumidifyer I picked up at target for about $50. It's about the size of a small space heater. I think the resevoir only holds about a cup of water before shutting off so I drilled a hole in the resevoir and glued in an elbow of small plastc pipe. I then put the dehumidifyer on the galley counter with the drain elbow over the sink. I keep the sink drain through-hull closed, just out of practice of keeping all through-hulls closed when I'm gone, and I'm always suprised how much water is collected. Granted, it's not buckets of water, but it does seem to be somewhat significant. I've never had any significant mildew or musty smell issues. in the winter though, it still just feels kind of damp in the boat. I'd be curious what people's take on space heaters is when you're not on board. Keeping a boat nice and warm inside seems like it would be even more effective at keeping the air dry and the mildew down. Maybe that in conjunction with the dehumidifyer would do wonders. I'm just too scared though to leave a space heater running....although as long as the amps are all within the limits of the boat's 110v system it seems like this should be okay.
I use a small dehumidifyer I picked up at target for about $50. It's about the size of a small space heater. I think the resevoir only holds about a cup of water before shutting off so I drilled a hole in the resevoir and glued in an elbow of small plastc pipe. I then put the dehumidifyer on the galley counter with the drain elbow over the sink. I keep the sink drain through-hull closed, just out of practice of keeping all through-hulls closed when I'm gone, and I'm always suprised how much water is collected. Granted, it's not buckets of water, but it does seem to be somewhat significant. I've never had any significant mildew or musty smell issues. in the winter though, it still just feels kind of damp in the boat. I'd be curious what people's take on space heaters is when you're not on board. Keeping a boat nice and warm inside seems like it would be even more effective at keeping the air dry and the mildew down. Maybe that in conjunction with the dehumidifyer would do wonders. I'm just too scared though to leave a space heater running....although as long as the amps are all within the limits of the boat's 110v system it seems like this should be okay.
Electric Heater
Bob, Be real scared if you like your boat. I don't know how to calculate the odds of a short, bad tip over switch, or other failure, but I think I know the odds of being able to salvage your boat if any of the above, or who knows what, did happen. ZERO. Dennis W. S/V FullSailed
Bob, Be real scared if you like your boat. I don't know how to calculate the odds of a short, bad tip over switch, or other failure, but I think I know the odds of being able to salvage your boat if any of the above, or who knows what, did happen. ZERO. Dennis W. S/V FullSailed
Dehumidifier
Got a friend that uses one on his Catalina all the time with no problems, runs the drain tube into the bilge. I've got one of the little West Marine heaters with the antifreeze setting on it that I've been using on my boat for 2 years with no problem.
Got a friend that uses one on his Catalina all the time with no problems, runs the drain tube into the bilge. I've got one of the little West Marine heaters with the antifreeze setting on it that I've been using on my boat for 2 years with no problem.
humidity
I have seen boats that had dehumidifiers running but they were sitting on the hard in the boatyard with the drain hose going out of a thru-hull. In the winter, the humidity is usually much lower than in the summer. I use a product called Damp-Rid that works pretty well. I usually get about a cup of water a week in the tub. Boats that have AC have a built in dehumidifier, but up here at the 45th parallel it doesn't get that hot in the summer, only a few days of hight temps and humidity.
I have seen boats that had dehumidifiers running but they were sitting on the hard in the boatyard with the drain hose going out of a thru-hull. In the winter, the humidity is usually much lower than in the summer. I use a product called Damp-Rid that works pretty well. I usually get about a cup of water a week in the tub. Boats that have AC have a built in dehumidifier, but up here at the 45th parallel it doesn't get that hot in the summer, only a few days of hight temps and humidity.
Ventilation is your first line of defence
against mold, mildew and that unpleasant musty odor in the drawers and on the bedding. The dehumidifier can't remove moisture from enclosed spaces. Do you have a means of measuring the relative humidity on the boat? Can you compare the humidity inside the boat with the relative humidity in the outside air. Is you boat dry as far as water in the bilge is concerned? Edit to add: measuring the dew point is an easy way to determine relative humidity with an accurate thermometer a tin can and some water and ice. fill the can about half full of water and put the thermometer into the water. start adding ice a little at a time until condensate forms on the outside of the can (you did take the label off, didn't you?)when condensate forms read the temperature . This is the dew point. Next you will need the air temperature. Then you go on line for this site. http://www.wrh.noaa.gov/sew/fire/olm/temp_rh.htm the rows of red numbers are dewpoints and the blue numbers are relative humidity. The dry bulb temperature is the air temperature.
against mold, mildew and that unpleasant musty odor in the drawers and on the bedding. The dehumidifier can't remove moisture from enclosed spaces. Do you have a means of measuring the relative humidity on the boat? Can you compare the humidity inside the boat with the relative humidity in the outside air. Is you boat dry as far as water in the bilge is concerned? Edit to add: measuring the dew point is an easy way to determine relative humidity with an accurate thermometer a tin can and some water and ice. fill the can about half full of water and put the thermometer into the water. start adding ice a little at a time until condensate forms on the outside of the can (you did take the label off, didn't you?)when condensate forms read the temperature . This is the dew point. Next you will need the air temperature. Then you go on line for this site. http://www.wrh.noaa.gov/sew/fire/olm/temp_rh.htm the rows of red numbers are dewpoints and the blue numbers are relative humidity. The dry bulb temperature is the air temperature.
Jeff, We have used one for some time
and think it's great. Contrary to what's been posted it does remove moisture and drains it off the boat. Some run it to the bilge or to a sink. As to a short and the boat being destroyed, I don't see any more risk than leaving your battery charger running when not on the boat. We return to a very dry boat. We purchased a Haier (sp?) form Target. It removes up to 45 pts a day of water and was very highly rated by consumer reports.
and think it's great. Contrary to what's been posted it does remove moisture and drains it off the boat. Some run it to the bilge or to a sink. As to a short and the boat being destroyed, I don't see any more risk than leaving your battery charger running when not on the boat. We return to a very dry boat. We purchased a Haier (sp?) form Target. It removes up to 45 pts a day of water and was very highly rated by consumer reports.
Stay below 50% RH
If you do research about how to avoid mold and mildew you'll find that staying below 50% RH is the thing to do. Besides that there should be air circulation, surfaces should be clean, etc. Buy something that measures relative humidity with some degree of accuracy, put it on board and watch the numbers over time. In Puget Sound it's common to be in the 70 to 80% RH inside the boat, even at times during the winter, so humidity is a problem. I've been running a dehumidifier for a couple years now and there has been virtually no mold or mildew problem so that's a real plus. The first year I had it set at the lowest possible setting which, I think, was 30% RH but may have been 35%. The unit was a 40-quart made by Fedders (but not a Fedders brand)(Fedders was sold by WalMart), the smallest I could find, that had an auto-defrost which is a must-have item. The air output is a few degrees warmer than ambient when it is running and the fan selection I kept at 'Low'. It also shuts off the compressor and fan when the target humidity is reached. The dehumidifier sits on the galley counter with a clear plastic tube going into the sink so it drains overboard. Whenever I went on board the boat always smelled clean - no musty smell. Cost to operate was about one-half to one-third less than running the space heaters. I still use a goldenrod or a space heater during the real cold snaps - in addition to the dehumidifier. This year, to save electricity, I set it for 40% RH to see how it works. Last year while looking at boats I went on the brokers 'dream boat', about a 70-foot power boat, and it had three large dehumidifiers running plus a few fans. No, I wasn't interested - he just wanted to show it to me because we were walking by. It was an Alaska charter boat with a displacement hull. Hope this helps.
If you do research about how to avoid mold and mildew you'll find that staying below 50% RH is the thing to do. Besides that there should be air circulation, surfaces should be clean, etc. Buy something that measures relative humidity with some degree of accuracy, put it on board and watch the numbers over time. In Puget Sound it's common to be in the 70 to 80% RH inside the boat, even at times during the winter, so humidity is a problem. I've been running a dehumidifier for a couple years now and there has been virtually no mold or mildew problem so that's a real plus. The first year I had it set at the lowest possible setting which, I think, was 30% RH but may have been 35%. The unit was a 40-quart made by Fedders (but not a Fedders brand)(Fedders was sold by WalMart), the smallest I could find, that had an auto-defrost which is a must-have item. The air output is a few degrees warmer than ambient when it is running and the fan selection I kept at 'Low'. It also shuts off the compressor and fan when the target humidity is reached. The dehumidifier sits on the galley counter with a clear plastic tube going into the sink so it drains overboard. Whenever I went on board the boat always smelled clean - no musty smell. Cost to operate was about one-half to one-third less than running the space heaters. I still use a goldenrod or a space heater during the real cold snaps - in addition to the dehumidifier. This year, to save electricity, I set it for 40% RH to see how it works. Last year while looking at boats I went on the brokers 'dream boat', about a 70-foot power boat, and it had three large dehumidifiers running plus a few fans. No, I wasn't interested - he just wanted to show it to me because we were walking by. It was an Alaska charter boat with a displacement hull. Hope this helps.
I spent one summer on the gulf coast and two rainy seasons in the
Philipine Islands. When the air temperature is high and the dew point is above 75 degrees it is very hard to stay cool because your sweat won't evaporate below 75 degrees. Everything that is cool will collect condensate and will mold or mildew. Dehumidifiers are the most practical way to deal with those conditions. A dehumidifier is simply an air conditioner the keeps the heat from the compressor in the same space. In Florida I would opt for a small AC. 5000 BTU will drag 5 pounds of water per hour out of the air. It won't get the air temperature below the dew point but it will lower the dew point as the humidity is reduced.
Philipine Islands. When the air temperature is high and the dew point is above 75 degrees it is very hard to stay cool because your sweat won't evaporate below 75 degrees. Everything that is cool will collect condensate and will mold or mildew. Dehumidifiers are the most practical way to deal with those conditions. A dehumidifier is simply an air conditioner the keeps the heat from the compressor in the same space. In Florida I would opt for a small AC. 5000 BTU will drag 5 pounds of water per hour out of the air. It won't get the air temperature below the dew point but it will lower the dew point as the humidity is reduced.
We use one all the time.
It keeps the interior dry and free of mildew. Our has humidity control which we set at 30-40% so the compressor does not run all the time. We connected a hose to lead condensed water down to the bilge.
It keeps the interior dry and free of mildew. Our has humidity control which we set at 30-40% so the compressor does not run all the time. We connected a hose to lead condensed water down to the bilge.
My next purchase will be a dehumidifier
Thanks for all the great advice. I really hadn't thought of letting it drain into the sink, but that sounds like the best solution. I think draining into the bilge might just add to the moisture problem? I live in Idaho and my boat is in Florida so I don't get out as often as I would like to. I keep a lot of clothes, linens, towels, etc on the boat so I don't have to carry them back and forth. I have an 18k btu and 16k btu A/C units but I really don't like letting them run for weeks/months on end, so the dehumidifier should be a great option.
Thanks for all the great advice. I really hadn't thought of letting it drain into the sink, but that sounds like the best solution. I think draining into the bilge might just add to the moisture problem? I live in Idaho and my boat is in Florida so I don't get out as often as I would like to. I keep a lot of clothes, linens, towels, etc on the boat so I don't have to carry them back and forth. I have an 18k btu and 16k btu A/C units but I really don't like letting them run for weeks/months on end, so the dehumidifier should be a great option.
Ventilation Works even in Florida
I put a house type vent in a piece of plywood and cut it to fit my companionway. This along with my other vents has kept my boat dry inside. But if you have water in the bilge and leaky windows you might still have a problem. But in my experience the sun heats up everything during the day and will dry out a boat that is well ventilated and doesn't ahve leaks. At night the water is often warmer than the air so the inside of the boat is warmer than the outside so again no condensation. Every boat that I've seem with mold had leaks and poor ventilation.
I put a house type vent in a piece of plywood and cut it to fit my companionway. This along with my other vents has kept my boat dry inside. But if you have water in the bilge and leaky windows you might still have a problem. But in my experience the sun heats up everything during the day and will dry out a boat that is well ventilated and doesn't ahve leaks. At night the water is often warmer than the air so the inside of the boat is warmer than the outside so again no condensation. Every boat that I've seem with mold had leaks and poor ventilation.
Just make sure that YOU are completely
comfortable with the connection of the sink drain to the through hull. You might want to consider triple hose clamps and new drain hose if you leave your through hull open for the dehumidifier drain.
comfortable with the connection of the sink drain to the through hull. You might want to consider triple hose clamps and new drain hose if you leave your through hull open for the dehumidifier drain.
Day/Night Vent and Light Bulbs do Fine for Me
I was real surprised at the difference it made might be worth a try. I was looking at a dehumidifier at first but decided I did not need one after the vent and bulbs were put on the boat.
I was real surprised at the difference it made might be worth a try. I was looking at a dehumidifier at first but decided I did not need one after the vent and bulbs were put on the boat.
Chemical Dehumidifier
If you go to Food Lion or any grocery store you can buy chemical dehumidifiers. They work great. I have three of them in my boat (2 in the salon and 1 in the bathroom). I don't need to change them too often (about 1 time a month) and it keeps mold and mildew out of the boat (really helpful for the bathroom). I highly reccommend them. It doesn't cost any power to run them and they will do a fine job.
If you go to Food Lion or any grocery store you can buy chemical dehumidifiers. They work great. I have three of them in my boat (2 in the salon and 1 in the bathroom). I don't need to change them too often (about 1 time a month) and it keeps mold and mildew out of the boat (really helpful for the bathroom). I highly reccommend them. It doesn't cost any power to run them and they will do a fine job.
Cannot Locate a Dehumidifier
It seems that up here in the Pacific NW they do not think it is very damp. I tried all of the stores you guys listed here (Targer, Wallmart) as well as Fred Meyer and Cosco. None carry dehumidifiers, at least in our region. Maybe it is a seasonal thing. Did you guys purchase these units in the summer? May have to go on line to see what I can find. I would like to get the smallest unit I can so online purchase may not be the best way to actually see the units. If anyone has any recomendations for specific models that are small, I would appreciate the help. Thanks for the interesting post.
It seems that up here in the Pacific NW they do not think it is very damp. I tried all of the stores you guys listed here (Targer, Wallmart) as well as Fred Meyer and Cosco. None carry dehumidifiers, at least in our region. Maybe it is a seasonal thing. Did you guys purchase these units in the summer? May have to go on line to see what I can find. I would like to get the smallest unit I can so online purchase may not be the best way to actually see the units. If anyone has any recomendations for specific models that are small, I would appreciate the help. Thanks for the interesting post.
Brad - May be a Seasonal Item
I bought mine from Home Depot around late January or early February a couple years ago. At the time both stores had some and HD in Bremerton had a lot. Talk to someone who is knowledgeable about when they get things in and see what they say, not some new-hire. Be sure, though, to get one with auto-defrost otherwise it'll have problems getting below 50% RH. The Fedders at the time had fairly good reports but it seems that many people don't really know how they're supposed to work and down-rate them because they can't figure things out and say "it's broken". Mine is a 40-qt which is fairly large and fills up my dock box. Since it's been a couple years now I'm thinking about cutting off the bottom where the water bucket is and reducing the size by over half. everything below the top of the bucket is just plastic anyway.
I bought mine from Home Depot around late January or early February a couple years ago. At the time both stores had some and HD in Bremerton had a lot. Talk to someone who is knowledgeable about when they get things in and see what they say, not some new-hire. Be sure, though, to get one with auto-defrost otherwise it'll have problems getting below 50% RH. The Fedders at the time had fairly good reports but it seems that many people don't really know how they're supposed to work and down-rate them because they can't figure things out and say "it's broken". Mine is a 40-qt which is fairly large and fills up my dock box. Since it's been a couple years now I'm thinking about cutting off the bottom where the water bucket is and reducing the size by over half. everything below the top of the bucket is just plastic anyway.
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