Quagmire Posted September 16, 2012 Share Posted September 16, 2012 Guys, if you keep your windscreen sparklingly clean inside it mists up much less! I keep a microfibre covered sponge thing on the dash and its excellent at keeping it dust free... Quote Link to comment Share on other sites More sharing options...
=jon= Posted November 29, 2012 Share Posted November 29, 2012 Slight bump as it's getting nippy out, and the fan in my defender is pants. Did you get any further with this Si? I swapped to a bilge blower on the series to try and get more air through, I did think of doing similar with two in parallel - one for position 1 on the fan, a second for position 2 - both forcing air into a Y piece on the inlet of the heater box. Quote Link to comment Share on other sites More sharing options...
RustyNissanPrairie Posted November 29, 2012 Share Posted November 29, 2012 can you rewind the armature to half the winds it has at the moment? Quote Link to comment Share on other sites More sharing options...
Geobloke Posted December 12, 2012 Share Posted December 12, 2012 I have been looking in to this as well. First with a view to finding a replacement fan motor, then an additional fan inline and more recently something like one of these DC to DC step-up adjustable voltage converters http://www.ebay.com/itm/DC-DC-Converter-3-25v-Step-up-to-adjustable-5-25v-2A-/260802129328 just concerned that it will not be man enough to cope with the amps (10A-15A fuse for the heater motor). Quote Link to comment Share on other sites More sharing options...
simonr Posted December 12, 2012 Author Share Posted December 12, 2012 OK, a bit of an update! I tried it and it works. The motor could take a lot more than 10A at 24v, but the DC/DC converter limits the current - which is no bad thing. The biggest problem is the noise! With the fan on full at 24v you can't hear the radio or engine! I bought a 24v speed controller from http://www.4QD.co.uk and with this, you can smoothly control the motor from nothing up to full tilt. I have a linear potentiometer (slider) and intend fitting this in place of the left hand control knob. In practice, because the knob also moves a cable (not sure what the purpose of the cable is) fitting proved a bit more complicated - and I didn't have time to complete it. I may just put a rotary knob on the dash to control the speed instead which would be simpler! I fancy the idea of one of the PTC heaters too - just so you get warm air as soon as you start the engine. I've looked at a couple but they are all too big. I fancy mounting it in the plenum chamber under the wing in line with the heater intake. I could modify the heater box and stick it in there, but if I can find one that is about 4 x 6" it would fit in the plenum. If it were small enough - it could even go in a box secured to the outside of the wing like one of the snow-cowls - which would be ever so easy to fit! Any ideas? Si Quote Link to comment Share on other sites More sharing options...
Big.Mike Posted December 12, 2012 Share Posted December 12, 2012 http://compare.ebay.co.uk/like/190755285704?var=lv<yp=AllFixedPriceItemTypes&var=sbar&adtype=pla&crdt=0 A couple of these might do it, I'm not sure if they have enough output? Quote Link to comment Share on other sites More sharing options...
landroversforever Posted December 12, 2012 Share Posted December 12, 2012 OK, a bit of an update! I tried it and it works. The motor could take a lot more than 10A at 24v, but the DC/DC converter limits the current - which is no bad thing. The biggest problem is the noise! With the fan on full at 24v you can't hear the radio or engine! I bought a 24v speed controller from http://www.4QD.co.uk and with this, you can smoothly control the motor from nothing up to full tilt. I have a linear potentiometer (slider) and intend fitting this in place of the left hand control knob. In practice, because the knob also moves a cable (not sure what the purpose of the cable is) fitting proved a bit more complicated - and I didn't have time to complete it. I may just put a rotary knob on the dash to control the speed instead which would be simpler! I fancy the idea of one of the PTC heaters too - just so you get warm air as soon as you start the engine. I've looked at a couple but they are all too big. I fancy mounting it in the plenum chamber under the wing in line with the heater intake. I could modify the heater box and stick it in there, but if I can find one that is about 4 x 6" it would fit in the plenum. If it were small enough - it could even go in a box secured to the outside of the wing like one of the snow-cowls - which would be ever so easy to fit! Any ideas? Si Simon, I think the cable connected to the fan speed lever opens and closes the flap on the exit of the heater box. (otherwise you would always get a flow of air, even with the heater switched off.) Quote Link to comment Share on other sites More sharing options...
simonr Posted December 12, 2012 Author Share Posted December 12, 2012 Mike, I think it needs to have a power of 1 to 2kw to make much difference. I've just tried pointing a 2kw convection heater into the wing intake - and the air was warm if not hot. Probably enough to demist though. If you search eBay for "Auxiliary Heater" there are several for BMW / Peugeot / Audi which look appropriate. The trouble is guessing the scale of the photographs. My plan is to use a Voltage Sensitive Relay (Durite 140A on eBay) so the heater will only switch on with the engine running and connect to the same switch as the heated mirrors. As I suggested above, I'll make a box which clips on to the intake on top of the wing and make it look like a snow cowel intake. To achieve this, I need to find the rough size of the elements. Si Quote Link to comment Share on other sites More sharing options...
Mo Murphy Posted December 12, 2012 Share Posted December 12, 2012 How about a brisk run around the block before commencing ones journey ? You won't be cold for the first 10 minutes of the journey and a heated screen will take care of any misting Mo Quote Link to comment Share on other sites More sharing options...
simonr Posted December 12, 2012 Author Share Posted December 12, 2012 a heated screen will take care of any misting As well as the half gallon of sweat now rapidly condensing on the glass! Si Quote Link to comment Share on other sites More sharing options...
TSD Posted December 12, 2012 Share Posted December 12, 2012 A PTC won't be heating the car to any great degree, but it can help to demist/defrost the screen much more quickly. It doesn't need to be particularly warm to demist, just needs to carry enough energy to raise the temp of the screen. Mine runs to around 800W at full chat. I wouldn't say the output in cold weather is warm, but it is definitely warmer than ambient within 30secs of startup, and the windscreen starts to demist. I suspect I forgot to seal a gap at one side of the panel, so will pull it out again when I have time to see if it can be better still. Remember that from a cold start the heater not only has to warm the air, but overcome the thermal loss to a cold metal dashboard tray before it reaches the screen. I did consider putting a plastic tube into the dash tray, with spray insulation around the outside, or even lining the inside of the tray with something to insulate it a bit - even underseal or stonechip paint might help. (One of these days, miketomcat will give in and start making fibreglass dashboards like we keep telling him to!) With your design Simon, you'll lose additional heat warming the heater box before you get warm air at the screen? Mine takes the 12V feed direct from the starter motor terminal, though it could use a better ground termination than I gave it. It noticeably dims the headlights when switched on Quote Link to comment Share on other sites More sharing options...
Geobloke Posted December 12, 2012 Share Posted December 12, 2012 The PTC in the wing plenum is a good idea, plenty of space in there. Best I could find is a Alibaba contact http://sell.bizrice.com/selling-leads/1205088/PTC-Heater-for-hand-dryer.html It says they can do it in 12v format and wattage-wise to your specs... The only thing that may put a spanner in the works is that the warm/hot air is passing through a cold heater matrix, on its way to the windscreen, with initially cold coolant passing through it keeping it chilled. The colder the morning the harder it is going to be to get the heat produced by the PTC element to the windscreen... The only other place for the element, albeit a much smaller (doesn't mean less powerful) PTC element is where the flexi-hoses are that lead to the windscreen dash vents. A little more challenging to get it to fit and you would need 2 (or would you? would just the drivers-side be enough??) but the only thing in the way of the heat is the windscreen. I tell you what. Crack this problem in a cost effective, plug and play manner and you're golden...! Quote Link to comment Share on other sites More sharing options...
simonr Posted December 12, 2012 Author Share Posted December 12, 2012 Thanks TSD - ill give it a go made out of cardboard first. If it doesn't work, I'll move it forwards in the airflow until it does! I've bought one on eBay from a BMW. It was cheap so no great loss if it fails. The control box for my winch lives next to the vent, wired in 70mm^2 to the battery. I doubt it will notice 100A or so! Si Quote Link to comment Share on other sites More sharing options...
TSD Posted December 13, 2012 Share Posted December 13, 2012 The control box for my winch lives next to the vent, wired in 70mm^2 to the battery. I doubt it will notice 100A or so! It's not entirely about the cabling, 100A is about 0.25V drop at the terminals of a typical Optima, but the real world drop is higher because the alternator provides most or all of the power, and it has a higher resistance than a battery. Say you had a 100A alternator and a 100A heater. With the engine running, you get (say) 14V at the battery, and it is charging at some current. Now you turn on the heater, it uses all the alternator current. Since the battery isn't charging or discharging, its terminal voltage will settle to around 12.8V - typical for a battery that's just been charged and is now at rest. So you see a voltage drop of 1.2V It's more complicated than that, of course, but that's the broad strokes of it. Quote Link to comment Share on other sites More sharing options...
rusty_wingnut Posted December 13, 2012 Share Posted December 13, 2012 Mike, I would check the connector into the heater. The three way job, mine had corroded to nothing Quote Link to comment Share on other sites More sharing options...
simonr Posted December 15, 2012 Author Share Posted December 15, 2012 An update! It's 4C outside at the moment - so not cold by any means. I gaffer taped the ceramic heater to my wing top covering the intake vent, set the heater controls to cold and connected it to the battery via jump leads. At startup it drew 140A settling down to 80A with the heater blower on full. Blower motor on half, it drew 38A. You can hear the engine speed dip when you connect it - so there is a decent load! These figures will be higher as the temperature drops - so I may need to watch out as my Alternator is 120A. The air coming out of the screen vents was at 14C after 30sec, 21C after 120 sec and didn't seem to get any warmer. Made little difference whether the fan was on half or full (as is the nature of PTC heaters). With the heater fan off, it drew 18A and got hotter them my thermometer would read so over 60C but not hot enough to burn me. At this point it was raining too! My conclusion is that if it can raise the temperature by 17C, that will make a big difference to demisting even if not de-icing. I think the easiest place to fit it would be in the plenum chamber immediately under the wing top. The end of the heater and wiring can point towards the front of the vehicle through a rectangular hole. Granted it will be less effective than putting it inside the heater box where it will have a lot less to heat up - but it's effective enough for me! Si Quote Link to comment Share on other sites More sharing options...
Retroanaconda Posted December 15, 2012 Share Posted December 15, 2012 Sounds good Si. Is it water-resistant? Just thinking that in that location it will likely get very wet from rain or even over-enthusiastic wading. Quote Link to comment Share on other sites More sharing options...
simonr Posted December 15, 2012 Author Share Posted December 15, 2012 It looks water resistant! Plastic & Aluminium construction. Time will tell though! Initially to try it, as I mentioned above, I plan to knock up a simple equivalent of a snow cowl to cover it. Rain falling directly on the heater is going to cause a fair bit of cooling - so best avoided! Si Quote Link to comment Share on other sites More sharing options...
need4speed Posted December 15, 2012 Share Posted December 15, 2012 I trust we will be seeing an x-heater soon si? Quote Link to comment Share on other sites More sharing options...
simonr Posted December 15, 2012 Author Share Posted December 15, 2012 Doubt it! The heaters are too expensive as a new part, and you can't really sell a product for which you have to source the main bit off eBay! Maybe what I'll do instead is post drawings of the mounting & wiring so people can easily make their own! Si Quote Link to comment Share on other sites More sharing options...
need4speed Posted December 15, 2012 Share Posted December 15, 2012 Maybe what I'll do instead is post drawings of the mounting & wiring so people can easily make their own! Good enough for me si. I will keep a keen eye out for the drawings. Quote Link to comment Share on other sites More sharing options...
ballcock Posted December 15, 2012 Share Posted December 15, 2012 Doubt it! The heaters are too expensive as a new part, and you can't really sell a product for which you have to source the main bit off eBay! Maybe what I'll do instead is post drawings of the mounting & wiring so people can easily make their own! Si Hi Si is this the sort of thing you've used? http://www.ebay.co.uk/itm/170751959969?ssPageName=STRK:MEWAX:IT&_trksid=p3984.m1423.l2649 Quote Link to comment Share on other sites More sharing options...
simonr Posted December 15, 2012 Author Share Posted December 15, 2012 That kind of thing! Mine cost £29 however - so probably worth a saved search and wait for something cheaper to turn up! Si Quote Link to comment Share on other sites More sharing options...
Daan Posted December 15, 2012 Share Posted December 15, 2012 Simon, if you look for a product to sell, why dont you go for exhaust heating? The energy source is there (which is wasted anyway). A bit like this, but exhaust to air heating: http://www.ebay.co.uk/itm/Mondeo-Mk3-2-0-TDCi-breaking-EXHAUST-MANIFOLD-WATER-HEATER-/180962864700?pt=UK_CarsParts_Vehicles_CarParts_SM&hash=item2a223a2e3c Daan Quote Link to comment Share on other sites More sharing options...
CwazyWabbit Posted December 15, 2012 Share Posted December 15, 2012 When you are using this setup Si would you say the normal heater is actually working against you? As in the heat exchanger is stealing your new heat and using it to warm the engine coolant? Quote Link to comment Share on other sites More sharing options...
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