reb78 Posted December 30, 2013 Share Posted December 30, 2013 My 110 seems fairly well sealed for a 110, but it still gets very damp inside. I run a 240 volt dehumidifier that sits in the back when I remember to switch it on and im near a plug but is there another way of doing this? The 240 volt one removes a fair amount of water, but even after it's run a while, on wet days, the windows are all covered up with condensation after driving for a while. If I had aircon, there would be a dehumidifier already fitted, but I don't have air con. I suspect the 12 volt ones you can buy are as much use as the ceramic 12 volt heaters, so what are my potential solutions to have a dehumidifier on the go as I'm driving?? Can I butcher and fit part of an aircon system to dehumidify the cab? Is there a 12 volt system that will work? Quote Link to comment Share on other sites More sharing options...
Ruurd Posted December 31, 2013 Share Posted December 31, 2013 My first action would be to check if the ventilation system is dry. Condensation is a matter of humid warm air touching a cold surface so the challenge is to use dry air instead of humid air - especially in the first part of the voyage. After a while there is a slight chance that your windows are warm enough not to fog over... on the other hand... it's a 110. Does it actually have heating... :-) I'd say: think DRY not HOT. Quote Link to comment Share on other sites More sharing options...
David Sparkes Posted December 31, 2013 Share Posted December 31, 2013 ... on wet days, the windows are all covered up with condensation after driving for a while.... so what are my potential solutions to have a dehumidifier on the go as I'm driving?? Can I butcher and fit part of an aircon system to dehumidify the cab? Is there a 12 volt system that will work? With the condensation increasing while driving, I'd suggest the root cause is a water leak that needs to be stopped. 'Water' may be rain, or road spray, or most likely coolant leaking from the heater matrix, which thus produces warm wet air, the 'wetness' condensating out as the air meets the cooler glass. I'm assuming you always ensure there is an escape route for the air you are blowing into the cab? Ventilation is about the movement of air into and out of an area, not 'just' heating the air within an area. No, you cannot butcher an aircon system to dehumidify the cab, you need the complete kit of compressor, condenser, and cooling matrix. You blow the hot air from your heater through the cooling matrix, which, being cool, causes the heated moisture to condensate out, and drain away beneath the vehicle. Any heated air that survives cooling is blown into the cab to warm it up. Yes, 12 volt dehumidifiers are available, they are sold to users of canal narrow boats, but are most commonly used while the boats are moored unattended, or moored 'static' for a while. HTH Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted December 31, 2013 Share Posted December 31, 2013 As above if your windows are still steamed up once you are well underway then there is a problem somewhere. I fitted extra demister vents to mine for the side windows but even before I did that the windscreen would be demisted within a few miles and stay so for the rest of the journey. Turning the air off would have it mist up again if there was a lot of moisture in the vehicle (ie. wet clothes or lots of people) but just having the air on low flow always keeps it cleared once it's been initially removed. Have you got water pooling in the heater inlet duct on the wing, or a matrix leak as suggested? The air coming in from outside ought to be more or less dry if all is well. Quote Link to comment Share on other sites More sharing options...
robertspark Posted December 31, 2013 Share Posted December 31, 2013 Is the fan working, is the air side of the heater maxtix blocked / restricted (does the air get warm)? does the vent controls switch from recirc to fresh air? Rearrly you want the vent controls on full recirc to start with, then once the air begins to heat up switch across to fresh air progressively. If you wish to know the science its to do with the psychometric properties of air. The simplest way to understand this is to look at a psychometric chart (you do not need to understand it fully) Chart - > http://refrigers.com/img_article/163e.jpg In short, if you heat air, the properties of the air move from left to right in a horizontal line (temperature scale is across the bottom). You will notice that on the right hand side, there is a scale which shows you the air moisture content, and this does not change with just heating the air. If you cool the air, the reverse is true, except for one caveat! If you cool the air and you cool it so much that the air temperature (following a horizontal line) touches the edge of the curve, then the air properties follow this curved line now, and the air gives up moisture. This is essentially dehumidification via electrical means (or air conditioning), and how a dehumidifier works. An interesting point is ----> the point at which the air temperature touches the curved part of the psychometric chart is the dew point (i.e. the point at which condensation forms on the surface). To give you an example ----> lets say your landrover sits outside in the cool of winter and the air vents are open, so over time the inside temperature is the same as the outside temperature, and it's well ventilated. The air will have a temperature of say 5ºC..... the worst condition would be a saturated air condition (i.e. it's raining outside). If you and 4 other mates now get into the landy and close the vents and turn on the heater (which is very slow responding).... then the moisture from your breath with condensate on the surfaces within the landrover.... as the air is already saturated and you are adding a small amount of heat in relation to the air temperature which is only rising slowly.... The problem does not resolve it's self until it's warm and toasty inside + has good air change (fresh air) at which point, the air will become dry and and able to absorb moisture. the other solution is to turn on the air con, and allow it to cool the air below 5 deg C --- remember the air is already near the curved part of the line, so the air will give up it's moisture, before being reheated by the heater as it heats up slowly. This then allows the air to be able to absorb more moisture. Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted December 31, 2013 Share Posted December 31, 2013 Defenders don't have recirculating air function. Just fresh air in or nothing! Quote Link to comment Share on other sites More sharing options...
cackshifter Posted December 31, 2013 Share Posted December 31, 2013 I think 'nothing' is more a hope than an option on mine - there's always some coming in somewhere. Quote Link to comment Share on other sites More sharing options...
TSD Posted December 31, 2013 Share Posted December 31, 2013 I think 'nothing' is more a hope than an option on mine - there's always some coming in somewhere. As robertspark said, it's a 'psychometric' property of air - which suggests it's only about how wet you think you are getting (I think he meant 'psychrometric') Quote Link to comment Share on other sites More sharing options...
Simon Smith Posted December 31, 2013 Share Posted December 31, 2013 I improved mine 100% by removing all the leaves, mud and water from the heater and the plastic duct, then fitted a snow cowl to stop the rain going in when it's parked. Quote Link to comment Share on other sites More sharing options...
Tanuki Posted December 31, 2013 Share Posted December 31, 2013 Over time, I've sealed-up most(!!) of the external leaks on my 90CSW: this has involved running a bead of clear "mould-resistant" silicone-seal along the gap where the windscreen meets the bulkhead, and doing the same down the sides/rear where the hardtop-part meets the lower tub. [Despite this I still sometimes find uninvited moistness in the driver's footwell: if you can tell me where it gets in I'd be eternally grateful] When driving, I generally open the two rear sliding side-windows an inch or so and set the heater to "full heat" and run the fan at maximum power: when parked-up under cover [my day-job has a secure underground car-park] I leave the side windows open and set both the bulkhead vent-flaps to fully-open so there's plenty of airflow. Lots of air-circulation is good. Heated air-circulation is better. None of this stops occasional evidence-of-condensation in the rear carpet/floor-mat area. I treat this by sticking a 1.8Kw fan-heater in the back overnight for a few nights in winter, then doing the 20-mile drive to work with all the windows/bulkhead vent-flaps open wide to drive out the hot, damp air. Quote Link to comment Share on other sites More sharing options...
mike4444244 Posted December 31, 2013 Share Posted December 31, 2013 +1 for the snow cowl, cheap and easy to fit and makes a big difference Quote Link to comment Share on other sites More sharing options...
Dads Toy Posted December 31, 2013 Share Posted December 31, 2013 Trying to de-mist the screen on my old 90 I turned the blower on full and got instant fog inside! Turned out to be water in the inlet duct to the blower. Previous owner had swapped the dump valve for a solid grommet so in wet weather there was a pool of water sat there just waiting for air to be blown over it and into the cab. It's a daft design with the inlet being open on the top of the wing letting rain in and if the valve isn't cleared regularly you get very humid air blown in. Malcolm Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted December 31, 2013 Share Posted December 31, 2013 I've found the easiest way to stop water accumulating in the inlet box is to remove the daft rubber valve and throw it away. Now water can escape unobstructed. Mo Quote Link to comment Share on other sites More sharing options...
Happyoldgit Posted December 31, 2013 Share Posted December 31, 2013 Defenders don't have recirculating air function. Just fresh air in or nothing! Ahem, Pumas do Anyway, glad the poxy valves in the heater air inlets have been mentioned, I cleared the ones on my Defender only this week. Quote Link to comment Share on other sites More sharing options...
robertspark Posted December 31, 2013 Share Posted December 31, 2013 TSD - > Oh dear, spellcheck / correct (can't spell if my life depended upon it). Tanuki - > Moisture in the footwell, I found mine had 2 potential sources of moisture in the footwell 1) the footwell is constructed of pressed sheets of metal / bent, then they appeared to be spot welded together at intervals. 2) mine had mats in the footwells, they were kindly secured to the footwell with self tapping screws...... I removed the decaying carpets, in both 1) & 2) I suspect the moisture was getting through from the wheel arch, and being forced in when the wheel was either going over wet roads or puddles, and the motion of the wheel was tracking the water up the mudflaps and onto the outside of the footwell then via the small screw holes (or via the gaps between the spot welds ... less so) and into the foot well. Previous owner also applied liberal amounts of silicone sealant around the top section of the footwell, near the doorstay, as I think this is where the top of the footwell joins the actual bulkhead section..... You could try getting a high powered inspection light in both the footwell and wheel arch to try to see from the other side if there is any light shining through anywhere.... (pref in the dark) Retroanaconda - > Oh dear, I forgot that there was not recirculation on a 90/110/130/def! -- school boy error, it's been so long since I had mine back on the road now! + I got rid of my dash, so my heater was either on or off. Solution to poor heating --- you could always fit an Eberspacher / Webasto diesel heater / an arctic heater ---- or something I was looking at trying ... installing two heater matrix's in series to provide more surface area. Quote Link to comment Share on other sites More sharing options...
Troll Hunter Posted January 2, 2014 Share Posted January 2, 2014 Since my CSW 110 was originally to middle east spec it had a reasonably good A/C but a lousy heater, all housed in a large container under the bonnet, bolted to the bulkhead. Two weeks ago, fed up with only getting luke warm air from the heater, I stripped the A/C and heater box and modified the internals. I totally removed the A/C evaporator, and cut out a large section of the baffle panel separating the A/C evaporator from the heater matrix. This very significantly improved both the air flow volume and temperature, since the air was no longer channeled around this baffle through quite a narrow gap, and flowing mainly through only one end of the heater matrix. It's still not instantly toasty, but after about half an hour I can turn the blower down from 4 to 2 - a very big improvement. I also renewed all the seals, internal and external, to prevent cold air by-passing the heater matrix. Now I only have to get the various flaps in the warm air duct working to be in total control ! Mike Quote Link to comment Share on other sites More sharing options...
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