After today,I think a fan inside,circulating the cold air,is as good as anything
I know our little 35 litre 3 way fridge came with a 12 volt fan pushing air up and over the cooling fins,from new
and still struggles on a hot day.
We took our 35 litre Waeco Thermoelectric to Sydney today,
My wife packed it this morning at 7.30 am with cold drinks etc,and techni Ice sheets
we got home to the Hunter valley at 7pm,everything still cold,and only the top sheet of ice
had softened slightly.
the Fridge/Cooler,has a little fan inside,circulating the air,which stops when the lid is opened.
admittedly,it was running on either 12 Volts,in the car,or 240 at my Sisters home,
still it's only a Thermo type
My guess is the small fan inside did it's job,as it was bloody hot all day.......still is
Hope this helps,I know there are plenty of helpful people on here,who know far more than I do,and may offer better advice
John
-- Edited by johnno02 on Sunday 2nd of December 2012 02:09:52 AM
jimricho said
07:41 AM Dec 2, 2012
I did some experimenting with fans at the back of the fridge and found the most effective solution was a small fan mounted below the condenser (for the benefit of others reading this thread, that's the finned gizmo at the top) and a larger fan mounted on the bottom vent. It doesn't need a lot of airflow just enough to keep the air circulating, more than this serves no purpose. In order to test the effectiveness I used a multimeter with a thermocouple attached to the fins. I generally found the fan on the bottom vent to be more effective than an exhaust fan on the top vent. Try the fan on the bottom vent first as it may be adequate without the fan under the condenser, I haven't checked this.
A switch or thermostat needs to be installed so that it runs only when needed as apparently in cooler conditions the boiler takes longer to come up to temperature and start the cycle operating. That advice came from a fridge techie that does a lot of work on 3-way fridges.
I also installed a baffle below the condenser to make sure the natural airflow was directed over the condenser. It is also recommended that the space around the sides of the fridge be filled with insulating material, I haven't done this (yet) as it involves removal and reinstalling the fridge.
I haven't tried installing a small fan inside the fridge but it may help. I've seen it suggested that power to this fan could be routed through the condensate drain.
-- Edited by jimricho on Monday 3rd of December 2012 06:33:04 AM
blaze said
08:26 AM Dec 2, 2012
who has put 12 volt fans on van fridges to assist with cooling. Our fridge is struggling ATM in broome. IT is a gas/240v running on 240v. The ice box is freezing but the frigde section isnt getting anywhere cool enough.
cheers
blaze
patrolst said
10:01 AM Dec 2, 2012
Try this the rear fan at the top has worked for me in forty degree heat at this time I haven't needed to install the internal fan. I have also wired in a led light beside the fridge controls to indicate when the fan is running.
But I have re done the top outlet directional baffle and installed compressed foam insulation down the backside edges of the fridge.
-- Edited by patrolst on Sunday 2nd of December 2012 10:04:43 AM
-- Edited by patrolst on Sunday 2nd of December 2012 10:15:42 AM
-- Edited by patrolst on Sunday 2nd of December 2012 10:25:12 AM
blaze said
11:27 PM Dec 2, 2012
just pulled the cover off the outside as I could get any fans so I thought that may help, low and behold there was 2 fans already in place but not going. Now guess who the dimwit was that removed a switch months ago as it didnt apear to have a use. Will see how these fans go now. I have relocated them to the highest point of the vent cover instead of the bottom of the vent cover. put a digital thermontor in there to see how the temp lowers, it was over 20 with bottles of ice in there to help. cheers blaze ps gotta love broome in the build up
jimricho said
02:30 AM Dec 3, 2012
blaze wrote:
Now guess who the dimwit was that removed a switch months ago as it didnt apear to have a use.
Mate, when it comes to dimwittery (is that a word?), I've been there done that!
blaze said
06:53 AM Dec 3, 2012
At this point it looks like we are getting 10 degrees colder but need to get it down a bit more yet. I would be putting a new fridge in if money wasnt so non exsistant Atm, just had to buy a new washing machine, 2.2kg fully auto for $347 in broome at retravision, checked out the same thing in camec in perth and the same machine was $540 cheers blaze
justcruisin01 said
07:06 AM Dec 3, 2012
I have two mounted on the top vent pulling air out, have not been in extreme conditions as yet, just put them on a toggle switch & turn when required.
Kiwi-as mounted some when he was here a few weeks ago.
They would have to make a huge difference getting that heat out.
For many years I have had fitted two small computor fans mounted on a alloy panel inserted into a rear sliding window above my car fridge/freezer that I run when parked, the inside car temp is generaly around 5deg above outside ambient temp, cant complain about that.
JC.
patrolst said
04:26 PM Dec 3, 2012
blaze wrote:
At this point it looks like we are getting 10 degrees colder but need to get it down a bit more yet. I would be putting a new fridge in if money wasnt so non exsistant Atm, just had to buy a new washing machine, 2.2kg fully auto for $347 in broome at retravision, checked out the same thing in camec in perth and the same machine was $540 cheers blaze
When you refit the toggle switch install the thermostat as well then if you are away from the van and forget to flick the switch on it will operate automatically when the temperature rises.
Baz421 said
05:00 PM Dec 3, 2012
A small computer fan (draws VERY little current) worked on my parents van in Darwin heat. Need to move the air over the fins.
Nomad246 said
05:11 PM Dec 3, 2012
This is a very good post, thanks Blaze for starting it.
Questions if I may
Does the fan aid better in hot weather when the fridge is on 240v, 12v or gas, or all three?
Also what about mobile on 12v or is it only run when the van is stationary?
Thanks
Dougwe said
10:38 PM Dec 3, 2012
I just had a computor fan installed inside the top vent to extract the hot air and helps a lot. A very big thankyou to kiwi-as for doing that job for me as I am not mechanically or electrically minded at all BUT I am learning as I go.
patrolst said
01:55 AM Dec 4, 2012
Nomad246 wrote:
This is a very good post, thanks Blaze for starting it.
Questions if I may
Does the fan aid better in hot weather when the fridge is on 240v, 12v or gas, or all three?
Also what about mobile on 12v or is it only run when the van is stationary?
Thanks
If you install the fan as noted on the site I posted with the thermostat installed it will run automatically on all 3 when the heat builds up as the fan only runs on 12volt.
We have had ours running when we have pulled up after travelling in hot weather with the sun beating on the fridge vent side while on 12volt.
As the
jimricho said
02:04 AM Dec 4, 2012
Nomad246 wrote:
This is a very good post, thanks Blaze for starting it.
Questions if I may
Does the fan aid better in hot weather when the fridge is on 240v, 12v or gas, or all three?
Also what about mobile on 12v or is it only run when the van is stationary?
Thanks
All three, both mobile or stationary. However don't expect it to work wonders in overcoming the lower efficiency of the fridge when on the move.
Digressing a little, on that last point I did some tests some time ago running the fridge on (notionally) 12v for an extended period while parked level and stationary for the whole time of the test and found that it operated just as well on 12v as on 240v. I came to a conclusion that the poorer performance on 12v while travelling may be due to the constant movement rather than the running on 12v. I used a 14 volt power supply to substitute for the battery for the test, but I have been able to compare this with 14 volts supplied from a voltage booster while travelling.
Nomad246 said
04:17 AM Dec 4, 2012
PatrolST, had a look at that site ,,, wondered how the 70C T/stat came to be ,,,,, I googled and I could not find a temp of the unit. I was wondering whether a 60C or higher t/stat would be the go.
Reason behind my thinking is battery power to drive the fan (yes I know It's mA) having only 100Ah reserve.
The fridge we have is a RM4601, so it's thirsty on battery and gas, given that freecamp will be on gas, I was working toward making it more efficient on gas use.
Specs on gas use for this fridge would have a 9Kg bottle empty in 2 weeks, so if it was more efficient, maybe the gas could last longer (detriment is battery power to do this)
Cheers
patrolst said
10:26 AM Dec 4, 2012
Nomad246 wrote:
PatrolST, had a look at that site ,,, wondered how the 70C T/stat came to be ,,,,, I googled and I could not find a temp of the unit. I was wondering whether a 60C or higher t/stat would be the go.
Reason behind my thinking is battery power to drive the fan (yes I know It's mA) having only 100Ah reserve.
The fridge we have is a RM4601, so it's thirsty on battery and gas, given that freecamp will be on gas, I was working toward making it more efficient on gas use.
Specs on gas use for this fridge would have a 9Kg bottle empty in 2 weeks, so if it was more efficient, maybe the gas could last longer (detriment is battery power to do this)
Cheers
Hi Nomad246.
The site I put up is not any thing to do with me just one I came across, and the fan installation in our van was as a precaution at the start as we have one of the "Electrolux" 4401 103ltr fridges. We have been in 36 to 40 deg heats and the fridge works well with the fan cutting in and out as required.
As for the 72deg thermostat it was trial and error for me as the fridge is a heat absorption unit the removal of to much heat from the cooling fins could be detriment to the operation of the fridge, this is why I have found it better to pull the heat out than push it through from the bottom. Others have had success with the fans installed at the bottom.
If the fridge had had some problem with the thermostat being too high I would have tried a lower temperature one. But as is the set up is working well.
As for the gas usage we usually get 7 to 8 days from a 4.5kg gas bottle for fridge operation and cooking while bush camping, the fridge spec. Notes 18.3gm per hourusage. The fridge is mostly running on temperature setting of 4 to 5 if in cooler climates it could need be taken down to 3
Some of the larger fridges would use more per hour.
The specifications your require should be found on the label stuck to the back wall in your fridge which will note all usage i.e. gas, 240vlt. 12vlt & Gas.
Please see the insert below, which notes that, the better the fridge installation the better the performance and efficiency
Refrigerator Installation
Correct ventilation basic for top performance
During the cooling process heat will be generated at the condenser fins on the backside of the refrigerator, which must be transferred with sufficient airflow to the ambient. If there is not enough space for the air to leave, the cooling performance will drop down and the energy consumption will rise. Incorrect ventilation could cause decline of refrigerators longevity.
To get the best performance the refrigerator needs at least 200 cm2 free air inlet and this space should be kept until the air outlet. Behind the rear border part please leave minimum 20 mm distance to the furniture wall.
-- Edited by patrolst on Tuesday 4th of December 2012 10:39:01 AM
-- Edited by patrolst on Tuesday 4th of December 2012 10:01:21 PM
patrolst said
10:36 AM Dec 4, 2012
As the post did not display the correct details I included please find them here./
-- Edited by patrolst on Tuesday 4th of December 2012 10:50:03 AM
jimricho said
04:10 PM Dec 4, 2012
3 way fridges are "thirsty" on energy, be it 12v, 240v, or gas. If it were not for the convenience of being able to operate on gas 3ways would have been assigned to the dustbin of history long ago. Operating a 3way on 12v only makes sense when connected to the vehicle's main battery and the engine is running, such as when on the move.
The battery power required to drive a suitable exhaust/inlet fan such as a Jaycar YX-2574 is only 80 milliamps or 0.08 amps so the draw on a 100ah battery is tiny.
It's my (very limited) understanding that the temperature of the condenser would ideally be about 40-45 degrees C. On this basis I think a 50 degree thermostat such as a Jaycar ST3831 attached to the fins would be appropriate. Note that the type of unit required is a normally open one (not normally closed). That is it closes ("switches on" in non-techiespeak) when the temperature exceeds 50 C.
It would be interesting to follow this up with a qualified absorption fridge technician as I'm a little out of my league here.
Nomad246 said
05:13 PM Dec 4, 2012
JR, that's where I was heading, to find the best operating temperature, so the t/stat would match (a little above) that temp. I couldn't find anything of relevance in google. Your suggestion of a Fridgies input would solve it.
I do understand NC/NO terms (but some might not) and was a trade account holder at Jaycar, so know their operation reasonably well.
I think I saw the fan you mention on the Jaycar webstore (without revisiting the store to check before writing this). It was a few $'s cheaper, a lot less mA but importantly about half the mean time before failure (mtbf) of the suggested fan. Also a lot lower cfm and l/m performance at about 3/4 of the rpm. Sounds a better option to select the more expensive suggested fan even if it means more mA, otherwise you'd use 2 of the cheaper fans to get the airflow.
I've used 3 way fridges for years for outback treks, but they were portable ones, not this huge thing we have in the new van, so I know how thirsty and quickly they drain a battery or a gas bottle (relevant to fridge size).
Strangely since this discussion, another discussion has popped up praising the rm4601 in it's performance. From what I have also learnt that fitting is a key. Maybe the fan just overcomes bad fitting?
Cheers
Nomad246 said
08:26 PM Dec 4, 2012
G'day PatrolST,
I think you have uncovered the most impotant info here ,,, "with sufficient airflow to the ambient"
this appears to me to mean that best operation is the ambient temp of airflow over the condensor fins. Hence forced airflow at whatever the outside air temp is.
I assume that if the area around the fins is allowed to rise (due to improper ventilation) above ambient, the internal of the fridge does the same, rises above desired.
Crude , but logical to me, so all the fridges that are installed with "good air circulation" as per requirements do not present as a problem. However installs that may be borderline potentially have cause to overheating (above ambient) and lesser cabinet efficiency.
Taken from this it can be determined that the ambient air temp in Aus is generally not above 45C. So a 50C t/stat would ensure proper operation,,, even a 40C t/stat would, but the fan may be running un-neccessarily on hot days.
Also,, we run 9kg bottles so your days between fills agree with our assumed usage.
Seems as a conclusion that if the fridge is installed "absolutely perfectly" by the van manufacturerer then it will work as intended. However if there is the slightest flaw in installation then forced ventilation will assist in efficiency.
I'm of the view that spending around $50 on parts to install yourself will be a good safegaurd for what could be hundreds of dollars of food in the fridge, not to mention where you are to go and shop to replace spoilage.
Dilemma now could be ,,,, why spend $000's on a van without failsafe ventilation for the fridge worth $0's.
Guys, thanks for your input.
PS: I've found this beneficial because my business background demands 100% redundancy (backup) with costs to be considered.
cheers
-- Edited by Nomad246 on Tuesday 4th of December 2012 08:29:45 PM
Captain said
09:35 PM Dec 7, 2012
I fitted a 12v fan with a separate switch so I can turn it on as needed. It works quite well. I also have a min/max thermometer on the wall above the fridge with the sensor inside the fridge. I can tell at a glance what the fridge temp is. In addition, I also pop rivetted a 1m length of sail track just below the top outside fridge vent and had a shade made to keep the sun off the fridge area. When positioning the van, try to keep the hot afternoon sun off the fridge side of the van but if this cannot be done, slide the shade in the track and peg it out from the van.
-- Edited by Captain on Friday 7th of December 2012 09:48:45 PM
justcruisin01 said
06:48 AM Dec 8, 2012
patrolst wrote:
As the post did not display the correct details I included please find them here./
-- Edited by patrolst on Tuesday 4th of December 2012 10:50:03 AM
This site shows insulation wool between the fridge & cabinates, both top & sides.
How many have got this?
We have the heat deflector plate as original equipment.
JC.
Nomad246 said
07:00 AM Dec 8, 2012
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
patrolst said
05:23 PM Dec 8, 2012
Nomad246 wrote:
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
Nomad 246
I think J.C. is referring to the "Dometic" fridge installation procedures that I posted where it shows that the fridge should be installed with insulation down the sidewalls and top of the cabinet.
I doubt very much if the caravan manufactures would bother to carry out this installation procedure, a lot of the time and the fridge installs I have seen they have difficulty installing the directional heat baffle at the top outlet properly.
jimricho said
02:54 AM Dec 9, 2012
Captain wrote:
I fitted a 12v fan with a separate switch so I can turn it on as needed. It works quite well. I also have a min/max thermometer on the wall above the fridge with the sensor inside the fridge. I can tell at a glance what the fridge temp is. In addition, I also pop rivetted a 1m length of sail track just below the top outside fridge vent and had a shade made to keep the sun off the fridge area. When positioning the van, try to keep the hot afternoon sun off the fridge side of the van but if this cannot be done, slide the shade in the track and peg it out from the van.
-- Edited by Captain on Friday 7th of December 2012 09:48:45 PM
When doing the tests I mentioned earlier I found that shading the wall from the sun (at any time of day) as you suggest made a big difference.
blaze said
05:35 AM Dec 9, 2012
I now have 5 computer fans helping to vent and can now maintain a rotten 10 degrees, have always had shade cloth covering the vents. also tried a fan inside the fridge trying different flows and it only made it worse. Over it, new fridge when we get back in the new year cheers blaze
justcruisin01 said
06:07 AM Dec 9, 2012
patrolst wrote:
Nomad246 wrote:
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
Nomad 246
I think J.C. is referring to the "Dometic" fridge installation procedures that I posted where it shows that the fridge should be installed with insulation down the sidewalls and top of the cabinet.
I doubt very much if the caravan manufactures would bother to carry out this installation procedure, a lot of the time and the fridge installs I have seen they have difficulty installing the directional heat baffle at the top outlet properly.
EXACTLY Patrolst in a nut shell.
Nomad 246, the web sit shows the wool insulation very clearly & as Patrolst said no one installs it .
Insulation makes a big difference to a lot of things, A fridge in a cabinate with a cavity all around it with no air flow then the unit will struggle from heat build up.
I beleive my point was valid & obvious.
JC.
Nomad246 said
10:33 PM Dec 10, 2012
justcruisin01 wrote:
patrolst wrote:
Nomad246 wrote:
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
Nomad 246
I think J.C. is referring to the "Dometic" fridge installation procedures that I posted where it shows that the fridge should be installed with insulation down the sidewalls and top of the cabinet.
I doubt very much if the caravan manufactures would bother to carry out this installation procedure, a lot of the time and the fridge installs I have seen they have difficulty installing the directional heat baffle at the top outlet properly.
EXACTLY Patrolst in a nut shell.
Nomad 246, the web sit shows the wool insulation very clearly & as Patrolst said no one installs it .
Insulation makes a big difference to a lot of things, A fridge in a cabinate with a cavity all around it with no air flow then the unit will struggle from heat build up.
I beleive my point was valid & obvious.
JC.
Valid and obvious ,,,,, the only thing that is obvious is that many users have issues with installed fridges. It is of no relevance to quote a premium way to install when what we have is what we got.
It is easy to "quote the manual" but many did not build the van and yet seek better results.
We all agree that if things were done to the manual, then nobody would have issues,,, however due to van design it happens that fridges are not always installed to the best result. A pompus attitude that you have would see the the van gutted to install as the manual required.
However this pursuit is about rectifying a negative to gain a positive outcome without building a van around a fridge, nor having an attitude that says what we bought was stupid. I also have a OEM heat deflector plate but I believe that there is gains to benefit from ,,,, even if everyone should have a fridge installed by the manual. Which not many has.
-- Edited by Nomad246 on Monday 10th of December 2012 10:40:41 PM
justcruisin01 said
12:57 AM Dec 12, 2012
Nomad246 wrote:
justcruisin01 wrote:
patrolst wrote:
Nomad246 wrote:
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
Nomad 246
I think J.C. is referring to the "Dometic" fridge installation procedures that I posted where it shows that the fridge should be installed with insulation down the sidewalls and top of the cabinet.
I doubt very much if the caravan manufactures would bother to carry out this installation procedure, a lot of the time and the fridge installs I have seen they have difficulty installing the directional heat baffle at the top outlet properly.
EXACTLY Patrolst in a nut shell.
Nomad 246, the web sit shows the wool insulation very clearly & as Patrolst said no one installs it .
Insulation makes a big difference to a lot of things, A fridge in a cabinate with a cavity all around it with no air flow then the unit will struggle from heat build up.
I beleive my point was valid & obvious.
JC.
Valid and obvious ,,,,, the only thing that is obvious is that many users have issues with installed fridges. It is of no relevance to quote a premium way to install when what we have is what we got.
It is easy to "quote the manual" but many did not build the van and yet seek better results.
We all agree that if things were done to the manual, then nobody would have issues,,, however due to van design it happens that fridges are not always installed to the best result. A pompus attitude that you have would see the the van gutted to install as the manual required.
However this pursuit is about rectifying a negative to gain a positive outcome without building a van around a fridge, nor having an attitude that says what we bought was stupid. I also have a OEM heat deflector plate but I believe that there is gains to benefit from ,,,, even if everyone should have a fridge installed by the manual. Which not many has.
-- Edited by Nomad246 on Monday 10th of December 2012 10:40:41 PM
Firstly, if anyone here has an attitude here its you. I only pointed out that the manufacture recomends the fitting of insulation as stated in their instruction.
I only indicated that this failure by instalers could contribute to the problems that every one has.
As for saying that I have an attitude here by saying that what you bought was stupid, WHERE & WHEN DID I SAY THAT??
Even my own doesn't have the insulation fitted so would I Call myself stupid? I think not when we have you trying to do it for me.
Get real mate.
Nomad246 said
09:22 PM Dec 13, 2012
After you have had your silly little rant ,,,
let's come up with options to fix what we have that may not be installed as per your advice as manufacturers of the fridge recommendations
as you now state even you do not have insulation, but your ealier comments focused on it.
Let's make good with new ideas what many have as an issue instead of quoting the bible of who makes the fridge.
In another post a roof vent works for someone that could install it
In our van a fan has been installed for, if and when, needed
Love to comply with your quoted fridge manufacturers proceedures ,,, but can't,,,, so why quote something that cannot be done
Regards , your "mate"
-- Edited by Nomad246 on Thursday 13th of December 2012 09:24:44 PM
Hi Blaze,
After today,I think a fan inside,circulating the cold air,is as good as anything
I know our little 35 litre 3 way fridge came with a 12 volt fan pushing air up and over the cooling fins,from new
and still struggles on a hot day.
We took our 35 litre Waeco Thermoelectric to Sydney today,
My wife packed it this morning at 7.30 am with cold drinks etc,and techni Ice sheets
we got home to the Hunter valley at 7pm,everything still cold,and only the top sheet of ice
had softened slightly.
the Fridge/Cooler,has a little fan inside,circulating the air,which stops when the lid is opened.
admittedly,it was running on either 12 Volts,in the car,or 240 at my Sisters home,
still it's only a Thermo type
My guess is the small fan inside did it's job,as it was bloody hot all day.......still is
Hope this helps,I know there are plenty of helpful people on here,who know far more than I do,and may offer better advice
John
-- Edited by johnno02 on Sunday 2nd of December 2012 02:09:52 AM
I did some experimenting with fans at the back of the fridge and found the most effective solution was a small fan mounted below the condenser (for the benefit of others reading this thread, that's the finned gizmo at the top) and a larger fan mounted on the bottom vent. It doesn't need a lot of airflow just enough to keep the air circulating, more than this serves no purpose. In order to test the effectiveness I used a multimeter with a thermocouple attached to the fins. I generally found the fan on the bottom vent to be more effective than an exhaust fan on the top vent. Try the fan on the bottom vent first as it may be adequate without the fan under the condenser, I haven't checked this.
A switch or thermostat needs to be installed so that it runs only when needed as apparently in cooler conditions the boiler takes longer to come up to temperature and start the cycle operating. That advice came from a fridge techie that does a lot of work on 3-way fridges.
I also installed a baffle below the condenser to make sure the natural airflow was directed over the condenser. It is also recommended that the space around the sides of the fridge be filled with insulating material, I haven't done this (yet) as it involves removal and reinstalling the fridge.
I haven't tried installing a small fan inside the fridge but it may help. I've seen it suggested that power to this fan could be routed through the condensate drain.
-- Edited by jimricho on Monday 3rd of December 2012 06:33:04 AM
who has put 12 volt fans on van fridges to assist with cooling. Our fridge is struggling ATM in broome. IT is a gas/240v running on 240v. The ice box is freezing but the frigde section isnt getting anywhere cool enough.
cheers
blaze
Try this the rear fan at the top has worked for me in forty degree heat at this time I haven't needed to install the internal fan. I have also wired in a led light beside the fridge controls to indicate when the fan is running.
http://www.dreampod.net/boroma/fridgefan.html
But I have re done the top outlet directional baffle and installed compressed foam insulation down the backside edges of the fridge.
-- Edited by patrolst on Sunday 2nd of December 2012 10:04:43 AM
-- Edited by patrolst on Sunday 2nd of December 2012 10:15:42 AM
-- Edited by patrolst on Sunday 2nd of December 2012 10:25:12 AM
cheers
blaze
ps
gotta love broome in the build up
Mate, when it comes to dimwittery (is that a word?), I've been there done that!
cheers
blaze
I have two mounted on the top vent pulling air out, have not been in extreme conditions as yet, just put them on a toggle switch & turn when required.
Kiwi-as mounted some when he was here a few weeks ago.
They would have to make a huge difference getting that heat out.
For many years I have had fitted two small computor fans mounted on a alloy panel inserted into a rear sliding window above my car fridge/freezer that I run when parked, the inside car temp is generaly around 5deg above outside ambient temp, cant complain about that.
JC.
When you refit the toggle switch install the thermostat as well then if you are away from the van and forget to flick the switch on it will operate automatically when the temperature rises.
A small computer fan (draws VERY little current) worked on my parents van in Darwin heat. Need to move the air over the fins.
This is a very good post, thanks Blaze for starting it.
Questions if I may
Does the fan aid better in hot weather when the fridge is on 240v, 12v or gas, or all three?
Also what about mobile on 12v or is it only run when the van is stationary?
Thanks
I just had a computor fan installed inside the top vent to extract the hot air and helps a lot. A very big thankyou to kiwi-as for doing that job for me as I am not mechanically or electrically minded at all BUT I am learning as I go.
If you install the fan as noted on the site I posted with the thermostat installed it will run automatically on all 3 when the heat builds up as the fan only runs on 12volt.
We have had ours running when we have pulled up after travelling in hot weather with the sun beating on the fridge vent side while on 12volt.
As the
All three, both mobile or stationary. However don't expect it to work wonders in overcoming the lower efficiency of the fridge when on the move.
Digressing a little, on that last point I did some tests some time ago running the fridge on (notionally) 12v for an extended period while parked level and stationary for the whole time of the test and found that it operated just as well on 12v as on 240v. I came to a conclusion that the poorer performance on 12v while travelling may be due to the constant movement rather than the running on 12v. I used a 14 volt power supply to substitute for the battery for the test, but I have been able to compare this with 14 volts supplied from a voltage booster while travelling.
PatrolST, had a look at that site ,,, wondered how the 70C T/stat came to be ,,,,, I googled and I could not find a temp of the unit. I was wondering whether a 60C or higher t/stat would be the go.
Reason behind my thinking is battery power to drive the fan (yes I know It's mA) having only 100Ah reserve.
The fridge we have is a RM4601, so it's thirsty on battery and gas, given that freecamp will be on gas, I was working toward making it more efficient on gas use.
Specs on gas use for this fridge would have a 9Kg bottle empty in 2 weeks, so if it was more efficient, maybe the gas could last longer (detriment is battery power to do this)
Cheers
Hi Nomad246.
The site I put up is not any thing to do with me just one I came across, and the fan installation in our van was as a precaution at the start as we have one of the "Electrolux" 4401 103ltr fridges. We have been in 36 to 40 deg heats and the fridge works well with the fan cutting in and out as required.
As for the 72deg thermostat it was trial and error for me as the fridge is a heat absorption unit the removal of to much heat from the cooling fins could be detriment to the operation of the fridge, this is why I have found it better to pull the heat out than push it through from the bottom. Others have had success with the fans installed at the bottom.
If the fridge had had some problem with the thermostat being too high I would have tried a lower temperature one. But as is the set up is working well.
As for the gas usage we usually get 7 to 8 days from a 4.5kg gas bottle for fridge operation and cooking while bush camping, the fridge spec. Notes 18.3gm per hour usage. The fridge is mostly running on temperature setting of 4 to 5 if in cooler climates it could need be taken down to 3
Some of the larger fridges would use more per hour.
The specifications your require should be found on the label stuck to the back wall in your fridge which will note all usage i.e. gas, 240vlt. 12vlt & Gas.
Please see the insert below, which notes that, the better the fridge installation the better the performance and efficiency
Refrigerator Installation
Correct ventilation basic for top performance
During the cooling process heat will be generated at the condenser fins on the backside of the refrigerator, which must be transferred with sufficient airflow to the ambient. If there is not enough space for the air to leave, the cooling performance will drop down and the energy consumption will rise. Incorrect ventilation could cause decline of refrigerators longevity.
To get the best performance the refrigerator needs at least 200 cm2 free air inlet and this space should be kept until the air outlet. Behind the rear border part please leave minimum 20 mm distance to the furniture wall.
-- Edited by patrolst on Tuesday 4th of December 2012 10:39:01 AM
-- Edited by patrolst on Tuesday 4th of December 2012 10:01:21 PM
As the post did not display the correct details I included please find them here./
http://www.dometicrvcentre.com.au/documentmanager/item/421
-- Edited by patrolst on Tuesday 4th of December 2012 10:50:03 AM
3 way fridges are "thirsty" on energy, be it 12v, 240v, or gas. If it were not for the convenience of being able to operate on gas 3ways would have been assigned to the dustbin of history long ago. Operating a 3way on 12v only makes sense when connected to the vehicle's main battery and the engine is running, such as when on the move.
The battery power required to drive a suitable exhaust/inlet fan such as a Jaycar YX-2574 is only 80 milliamps or 0.08 amps so the draw on a 100ah battery is tiny.
It's my (very limited) understanding that the temperature of the condenser would ideally be about 40-45 degrees C. On this basis I think a 50 degree thermostat such as a Jaycar ST3831 attached to the fins would be appropriate. Note that the type of unit required is a normally open one (not normally closed). That is it closes ("switches on" in non-techiespeak) when the temperature exceeds 50 C.
It would be interesting to follow this up with a qualified absorption fridge technician as I'm a little out of my league here.
JR, that's where I was heading, to find the best operating temperature, so the t/stat would match (a little above) that temp. I couldn't find anything of relevance in google. Your suggestion of a Fridgies input would solve it.
I do understand NC/NO terms (but some might not) and was a trade account holder at Jaycar, so know their operation reasonably well.
I think I saw the fan you mention on the Jaycar webstore (without revisiting the store to check before writing this). It was a few $'s cheaper, a lot less mA but importantly about half the mean time before failure (mtbf) of the suggested fan. Also a lot lower cfm and l/m performance at about 3/4 of the rpm. Sounds a better option to select the more expensive suggested fan even if it means more mA, otherwise you'd use 2 of the cheaper fans to get the airflow.
I've used 3 way fridges for years for outback treks, but they were portable ones, not this huge thing we have in the new van, so I know how thirsty and quickly they drain a battery or a gas bottle (relevant to fridge size).
Strangely since this discussion, another discussion has popped up praising the rm4601 in it's performance. From what I have also learnt that fitting is a key. Maybe the fan just overcomes bad fitting?
Cheers
G'day PatrolST,
I think you have uncovered the most impotant info here ,,, "with sufficient airflow to the ambient"
this appears to me to mean that best operation is the ambient temp of airflow over the condensor fins. Hence forced airflow at whatever the outside air temp is.
I assume that if the area around the fins is allowed to rise (due to improper ventilation) above ambient, the internal of the fridge does the same, rises above desired.
Crude , but logical to me, so all the fridges that are installed with "good air circulation" as per requirements do not present as a problem. However installs that may be borderline potentially have cause to overheating (above ambient) and lesser cabinet efficiency.
Taken from this it can be determined that the ambient air temp in Aus is generally not above 45C. So a 50C t/stat would ensure proper operation,,, even a 40C t/stat would, but the fan may be running un-neccessarily on hot days.
Also,, we run 9kg bottles so your days between fills agree with our assumed usage.
Seems as a conclusion that if the fridge is installed "absolutely perfectly" by the van manufacturerer then it will work as intended. However if there is the slightest flaw in installation then forced ventilation will assist in efficiency.
I'm of the view that spending around $50 on parts to install yourself will be a good safegaurd for what could be hundreds of dollars of food in the fridge, not to mention where you are to go and shop to replace spoilage.
Dilemma now could be ,,,, why spend $000's on a van without failsafe ventilation for the fridge worth $0's.
Guys, thanks for your input.
PS: I've found this beneficial because my business background demands 100% redundancy (backup) with costs to be considered.
cheers
-- Edited by Nomad246 on Tuesday 4th of December 2012 08:29:45 PM
I fitted a 12v fan with a separate switch so I can turn it on as needed. It works quite well. I also have a min/max thermometer on the wall above the fridge with the sensor inside the fridge. I can tell at a glance what the fridge temp is. In addition, I also pop rivetted a 1m length of sail track just below the top outside fridge vent and had a shade made to keep the sun off the fridge area. When positioning the van, try to keep the hot afternoon sun off the fridge side of the van but if this cannot be done, slide the shade in the track and peg it out from the van.
-- Edited by Captain on Friday 7th of December 2012 09:48:45 PM
This site shows insulation wool between the fridge & cabinates, both top & sides.
How many have got this?
We have the heat deflector plate as original equipment.
JC.
Failing to see the relevance of your post JC ,,,, where are you heading with that comment
You "have the heat deflector plate as original equipment" ,, enlighting us what that does and why the comment on insulation that probably isn't there
Nomad 246
I think J.C. is referring to the "Dometic" fridge installation procedures that I posted where it shows that the fridge should be installed with insulation down the sidewalls and top of the cabinet.
I doubt very much if the caravan manufactures would bother to carry out this installation procedure, a lot of the time and the fridge installs I have seen they have difficulty installing the directional heat baffle at the top outlet properly.
When doing the tests I mentioned earlier I found that shading the wall from the sun (at any time of day) as you suggest made a big difference.
cheers
blaze
EXACTLY Patrolst in a nut shell.
Nomad 246, the web sit shows the wool insulation very clearly & as Patrolst said no one installs it .
Insulation makes a big difference to a lot of things, A fridge in a cabinate with a cavity all around it with no air flow then the unit will struggle from heat build up.
I beleive my point was valid & obvious.
JC.
Valid and obvious ,,,,, the only thing that is obvious is that many users have issues with installed fridges. It is of no relevance to quote a premium way to install when what we have is what we got.
It is easy to "quote the manual" but many did not build the van and yet seek better results.
We all agree that if things were done to the manual, then nobody would have issues,,, however due to van design it happens that fridges are not always installed to the best result. A pompus attitude that you have would see the the van gutted to install as the manual required.
However this pursuit is about rectifying a negative to gain a positive outcome without building a van around a fridge, nor having an attitude that says what we bought was stupid. I also have a OEM heat deflector plate but I believe that there is gains to benefit from ,,,, even if everyone should have a fridge installed by the manual. Which not many has.
-- Edited by Nomad246 on Monday 10th of December 2012 10:40:41 PM
Firstly, if anyone here has an attitude here its you. I only pointed out that the manufacture recomends the fitting of insulation as stated in their instruction.
I only indicated that this failure by instalers could contribute to the problems that every one has.
As for saying that I have an attitude here by saying that what you bought was stupid, WHERE & WHEN DID I SAY THAT??
Even my own doesn't have the insulation fitted so would I Call myself stupid? I think not when we have you trying to do it for me.
Get real mate.
After you have had your silly little rant ,,,
let's come up with options to fix what we have that may not be installed as per your advice as manufacturers of the fridge recommendations
as you now state even you do not have insulation, but your ealier comments focused on it.
Let's make good with new ideas what many have as an issue instead of quoting the bible of who makes the fridge.
In another post a roof vent works for someone that could install it
In our van a fan has been installed for, if and when, needed
Love to comply with your quoted fridge manufacturers proceedures ,,, but can't,,,, so why quote something that cannot be done
Regards , your "mate"
-- Edited by Nomad246 on Thursday 13th of December 2012 09:24:44 PM