sakofox Posted June 30, 2017 Share Posted June 30, 2017 A couple of questions. How important is it to keep the fly screens on the fridge vents, can they be removed permanently? If adding a couple of fans to extract the warm air, where is the best place to take the 12v supply from. I have a dometic 8501 fridge in an Auto-trail Link to comment Share on other sites More sharing options...
Derek Uzzell Posted June 30, 2017 Share Posted June 30, 2017 This earlier discussion may help http://forums.outandaboutlive.co.uk/forums/Motorhomes/Motorhome-Matters/additional-fans-for-fridge/31039/ Removing the fly-screens should improve the air-flow significantly (+50%?) but obviously there will be more potential for insects to enter. Fly-screens never used to be fitted to Dometic fridges, so removing them should cause no harm. Link to comment Share on other sites More sharing options...
BKen1 Posted June 30, 2017 Share Posted June 30, 2017 You obviously plan to travel to warmer climes ,removing the fly screen will improve air flow as Derek says but my experience is you will find the insect population are always on the lookout for places to build there nests and without the screen they will diffinetly get in the rear of the fridge.They just love the nooks and crannies around the pilot light and connector blocks so I would advice against removing the screens. And if you fit a fan you should have some screening over the it as well. Brian K Link to comment Share on other sites More sharing options...
Pete-B Posted June 30, 2017 Share Posted June 30, 2017 I would say, (do not remove them) my son got some flies in the back of his fridge which caused a short out which in turn could have caused a bad fire. The fridge had to be replaced and the company refused a warranty claim. Link to comment Share on other sites More sharing options...
aandncaravan Posted July 1, 2017 Share Posted July 1, 2017 We would advise not to remove them, in agreement with those above about insects, Spiders, etc, but also because they are valuable in reducing Water Spray into the area behind the Fridge. While they are obviously not water Proof, they can to reduce the ingress of Water by breaking up the water flow, like when Washing the vehicle. Obviously anyone Jet washing the van or playing a hose pipe directly on the vents will still cause serious issues, but lighter Water patterns, like Rain Spray, can be reduced significantly by a Mesh screen. As said above, many of the Fridge burner faults we see are down to Spiders making nests in that area. If you do remove the mesh, suggest you take extra care Washing and try to run the Fridge on Gas once a month. When you do 'Gas the Fridge' leave it on for a couple of hours so the burner gets really hot not just to burn off the Cob webs, but to fully 'vaporise' any Carbon deposits that can result from just a 5 minute 'burn'. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 1, 2017 Share Posted July 1, 2017 A similar question was asked here https://www.motorhomefun.co.uk/forum/threads/removing-insect-screen-on-fridge-vent.125444/ Whatever the potential value of the mesh to prevent insect entrance or water ingress when vehicle washing, it is nevertheless the case that the mesh inhibits the air-flow and this restriction may become important in very hot weather conditions. It's a Dometic thing - current Thetford fridge vents have no mesh. Link to comment Share on other sites More sharing options...
aandncaravan Posted July 1, 2017 Share Posted July 1, 2017 On the question of the Power Point : The Dometic 8501 has a optional cooling fan kit that is thermostatically controlled, are you fitting this or making up you own thermo controlled version? It says that the 8501 Fan kit is easy to install, so there may already be a power 'pick up' point available? While I would imagine the Dometic kit is three times the cost of a home made version, it might be an easier option and worth it just for the thermostatic control? If you are making your own fan version and can't find the power point for the Optional kit, then you should find three other 12v supplies at the rear of the unit. There will be one to power the 12v Element (usually much fatter cabling) that is only live when the engine is running. The second is the trigger circuit from the Alternator, which again will only be live when the Alternator is spinning/engine running. The third one is permanently live (usually only around a 1 - 2 amp supply so thin cabling) for the Fridge Controller circuitry. Obviously the third one is the one to wire into. Link to comment Share on other sites More sharing options...
sakofox Posted July 1, 2017 Author Share Posted July 1, 2017 Many thanks that is really helpful. The dometic kit is over £90 for one fan, and it does appear to plug into the circuit board, but I cannot access that easily. I will go for a twin kit with thermostat and a three way switch. I believe CAK tanks make one already wired. Thanks again Link to comment Share on other sites More sharing options...
Derek Uzzell Posted July 1, 2017 Share Posted July 1, 2017 A twin-fan kit is also available here http://www.outdoorbits.com/motorhome-double-fridge-fan-p-1880.html Link to comment Share on other sites More sharing options...
BRS1950 Posted July 3, 2017 Share Posted July 3, 2017 Hi you guys, you all seam to be talking about fridges efficiency when you are stationary, what I would like to know is how to improve the efficiency of a 12v fridge when on the move. The fridge does not seam to hold its original temp after quite a short time. I have understood by reading forums that the most effective way is by gas, but that too has it restrictions, like when refilling at a petrol station etc. that 12v does not. Any suggestions would be appreciated Link to comment Share on other sites More sharing options...
aandncaravan Posted July 3, 2017 Share Posted July 3, 2017 Without knowing a lot more about your vehicle, motorhome manufacturer, Fridge, Charger/Power Controller, it is not so easy to advise. Some Fridges are so good on 12v they will freeze the contents, others just keep it cool. If the Fridge itself is one of those able to keep the contents properly cool on a hot day, then any 'malfunction' is likely to be down to the 14.4v supply at the Fridge? One poor connection can have a big impact. There are often many things you can do like ensuring the Alternator has a perfect 'Engine Earth', battery quality, cabling, connections, etc. Please can you supply all the details you can, even battery type/condition is important as poor batteries can drag power away from the Fridge. Link to comment Share on other sites More sharing options...
sakofox Posted July 3, 2017 Author Share Posted July 3, 2017 The fridge is in a new auto-trail, 5 months old. Dometic 8501. The issue is the ventilation at the back of the fridge . I have now added a baffle to deflect the rising air through the cooling fins. Under normal conditions, it is 25c today, the fridge and freezer are working correctly. I will be keeping the fly screens in place as recommended. If the baffles are in affective at 30c then I will fit a twin fan to the top vent. Thank you for you help. Link to comment Share on other sites More sharing options...
BRS1950 Posted July 3, 2017 Share Posted July 3, 2017 this unit(MH) is brand new, so all should be well. But I have had 3 units before and all suffered the same drawback, so I feel it is a generic fault. The fridge I have now is a Dometic in a bailey Autograph. Link to comment Share on other sites More sharing options...
steve101 Posted July 31, 2017 Share Posted July 31, 2017 sakofox - 2017-07-03 5:11 PM The fridge is in a new auto-trail, 5 months old. Dometic 8501. The issue is the ventilation at the back of the fridge . I have now added a baffle to deflect the rising air through the cooling fins. Under normal conditions, it is 25c today, the fridge and freezer are working correctly. I will be keeping the fly screens in place as recommended. If the baffles are in affective at 30c then I will fit a twin fan to the top vent. Thank you for you help. Are you able to take a picture of your baffles for me? Or maybe describe how you made / attached them etc? I am in a similar situation where it was a poor install by the manufacturer, it has an oversized gap at the rear. Thank you. Link to comment Share on other sites More sharing options...
sakofox Posted July 31, 2017 Author Share Posted July 31, 2017 Hello, there is a bit in our blog along with pictures http://ionamotorhome.blogspot.co.uk/2017/07/the-cotswolds-and-beyond.html basically I made a 'v' shaped piece of 2mm aluminium, it is bolted to the fridge vent surround with a bit of ply packing between the aluminium and the plastic. I had to cut it in two because a single piece would not fit in. Hope that helps Link to comment Share on other sites More sharing options...
steve101 Posted July 31, 2017 Share Posted July 31, 2017 Funnily enough I was thinking about V shapes earlier. At the moment I have the same gap as you did. I have mounted a PC fan under the cooling fins as prescribed by Dometic. Cleaned the unit and added some insulation. I have also extended the flue towards the vents with a small section of pipe so it doesn't exhaust near / onto the fins. I too am waiting for warmer weather to test it prior to looking at the baffle option again. Link to comment Share on other sites More sharing options...
steve101 Posted August 1, 2017 Share Posted August 1, 2017 Your blog is very good. Did you bend the ali yourself? Any tips on cutting and bending? Link to comment Share on other sites More sharing options...
747 Posted August 1, 2017 Share Posted August 1, 2017 sakofox - 2017-07-31 6:33 PM Hello, there is a bit in our blog along with pictures http://ionamotorhome.blogspot.co.uk/2017/07/the-cotswolds-and-beyond.html basically I made a 'v' shaped piece of 2mm aluminium, it is bolted to the fridge vent surround with a bit of ply packing between the aluminium and the plastic. I had to cut it in two because a single piece would not fit in. Hope that helps It's a small World. :D We were also on the THS at Merryweather Farm from the 3rd to 5th July. We were in the Burstner Tag Axle van at the far end of the field (next to the Dog exercise area. Link to comment Share on other sites More sharing options...
sakofox Posted August 1, 2017 Author Share Posted August 1, 2017 Hi, yes we remember seeing you , you left a day before us. The next time I see a burst near tag axle I'll knock on the door and say hello, it maybe you. Link to comment Share on other sites More sharing options...
Derek Uzzell Posted August 2, 2017 Share Posted August 2, 2017 steve101 - 2017-08-01 12:09 PM Your blog is very good. Did you bend the ali yourself? Any tips on cutting and bending? As far as I can make out, the ‘baffle’ does not need to be particularly strong. I note that sakofox used 2mm-thick aluminium sheet, but significantly thinner material should be plenty adequate and a good deal simpler to work with. Screwfix offers aluminium sheet with a thickness of 0.75mm http://www.screwfix.com/p/alfer-metal-sheet-aluminium-120-x-1000mm/7322p and this can be cut with tin-snips (or a fine-tooth saw) and is easily bent. I used it to make a simple heat shield for my Rapido’s hob when the original complicated rattly hinged shield glued to the hob’s glass lid fell off. Link to comment Share on other sites More sharing options...
sakofox Posted August 2, 2017 Author Share Posted August 2, 2017 Steve101 I cut it with an electric fretsaw but as someone else has said the 2mm Ali was a bit over engineered. Thinner sheet would do the job and be easier to work. Link to comment Share on other sites More sharing options...
Basil Posted August 2, 2017 Share Posted August 2, 2017 Derek Uzzell - 2017-07-01 8:44 PM A twin-fan kit is also available here http://www.outdoorbits.com/motorhome-double-fridge-fan-p-1880.html I have just installed this peice kit yesterday and found it very easy and seemingly effective. Clearly we won't know if it has cured the problem until we again experience the above 41degC temperature we experienced in Southern France and Spain last month. We found the fridge a Dometic RM8041 was not able to freeze during the day and we lost frozen meat and ice lollies. First impressions are good as the air movement is exceptional and is extremely quiet. The control panel fits exactly into the flat recess on the fridge front panel immediately above the top opening press 'button' without any interference with opening the fridge. all wiring can be made at the rear of the fridge and both the live feed 12v+, taken from the fridges permanent live (violet on ours), and the earth 12v-, to the fridges earth (black on ours) the other three wires go to the thermal switch and to the fans that are installed easily into the top vent, a very simple job. Bas Link to comment Share on other sites More sharing options...
sakofox Posted August 7, 2017 Author Share Posted August 7, 2017 Thanks Basil, I have just found the white/black/violet cable so the next step is to check the voltage and install my two fans and the thermal switch, I have a three way switch (on/off/auto) to add to the fridge front, Link to comment Share on other sites More sharing options...
steve101 Posted August 8, 2017 Share Posted August 8, 2017 I have finished fiddling with mine. The baffle is now installed. On a side note I emailed Dometic to ask why they say the fans should be installed under the fins. Here is their reply: We recommend the fan is instilled under the cooling fins, this allows the cool air to be dragged through the fins, Installing the fan behind the vent leaves the fan exposed to the weather, can create issues when removing the vent as there will be cables present, the fan will draw air up but the air will may move past the fins not be pulled through the fins, Installing the fan behind the vent also reduces the amount of available ventilation when the fan is not in use, I hope this helps to clarify. Link to comment Share on other sites More sharing options...
sakofox Posted August 8, 2017 Author Share Posted August 8, 2017 Hi Steve101 I saw dometic put the fan under the fins, but on my set up there is no room under the fins and if there was I would have to take the fridge out to fit it. I am going to try and fit everything without attaching it to the fridge, to save any issues if the fridge ever has to be pulled out. The fans will be fitted to the fridge vent frame and not the cover so I will be able to hide all the wires and the fans are set back from the cover, so they should not be exposed to the elements, especially when the winter covers are fitted. I did think there may be an issue if the fans are not in use as they fill 3/4 of the vent, but I can put them on auto so they come on if the heat builds up. It should be ok in the cooler months. I will post they initial results once set up. Link to comment Share on other sites More sharing options...
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