From speaking to our guests over the years I have noticed there is quite a bit of confusion around fridge vents. For instance, what the vents are for and why would you want to fit vent covers in the winter months? So with today’s post that’s the topic I’m going to discuss. However, when it comes to fridge vents and ventilation, in general, its not only the winter months you need to think about. In the UK we generally have mild to warm summers. However, we are seeing a general trend in warm summer temperatures. Well, that can create a problem for your caravan fridge/freezer with a drop in performance. However, there are means (DIY and official) to improve the ventilation around the fridge vents which I’ll also discuss.
Now, the topic of fridge vents is only applicable to you if your caravan/motorhome uses a 3-way absorption fridge. An absorption fridge can use 12V, 230V and LPG as a source of energy. If your caravan/motorhome has a compressor fridge as you do at home that works on a different principle, hence it doesn’t require external fridge vents. Its generally much more common to find 3 -way absorption fridges on caravans than motorhomes or campervans. However, caravans, motorhomes or campervans can be fitted with either a 3-way fridge or a compressor fridge/freezer. In this post I’m not going to discuss the pros and cons of absorption fridge/freezers over compressor fridge/freezers, I’ll save that for a later post. For now, just for clarification, not all caravans, motorhomes and campervans actually have external fridge vents.
Introduction to Caravan Fridge Vents
So unless you are a caravan beginner or a motorhome beginner you will probably already know at least something about fridge vents. But please note as I stated above, not all caravans/motorhomes have/need fridge vents depending on the type of fridge/freezer installed. So if you don’t see any fridge vents on the outside of your caravan or motorhome don’t worry about it, this post is not applicable to you. If you do have external fridge vents on your leisure vehicle they will typically look like those in the video below.
So as you can see from the video above, if a caravan or motorhome has an absorption 3-way fridge it will have two external vents. Why? Well, I’ll discuss that below. But the point being, there will be two vents and both are important for proper ventilation and good efficient operation of the fridge. How do you remove caravan fridge vent covers? Well simply watch the 1-minute video above. Whether you have a Dometic or a Thetford 3-way fridge the same basic fixing and release clips are located under the top edge of the fridge vent covers. Its important to know how to remove and fit a caravan fridge vent cover.
Typical Dometic (LS100) vent kit (summer/wwinter) for a caravan/motorhome with a 3-way absorption fridge/freezer: Image – Amazon
Why Do Caravan 3-Way Fridges Need Vents?
So why does your caravan fridge need a vent at all, and why does it need two vents? We’ll its due to the way an absorption fridge works which is very different a compressor fridge/freezer found in your home and other leisure vehicles. An absorption fridge does not have any moving mechanical parts. The cooling process is based on physics, chemistry and thermodynamic principles of how chemicals react to temperature differences. The video below provides a very easy to understand/straight forward explanation of how the cooling/freezing process works.
In this particular post, I don’t want to get too much into the topic of how a 3-way fridge works, I’ll save that for a later post. What I do want to discuss here is why the fridge needs external vents for this absorption cooling process to work. From the video above you can see the cooling process relies on condensers/heat exchangers. Well, for a condenser/heat exchanger to function it needs a temperature difference. Therefore it needs outside air ventilating over the condenser/heat exchanger to pass that heat energy (from inside the fridge/freezer) into the outside environment. Hence, the reason why external vents are required in the caravan/motorhome body behind the 3-way adsorption fridge.
Why Are There Two Fridge Vents?
The first reason is that you have a lower fridge heat exchanger and a higher freezer heat exchanger that both require ventilation. The second reason there are two vents is to create a draft, similar to how a boiler or stove works with a chimney. Its also similar to how radiators work in your home. Fresh incoming cool air is brought in through the lower vent, it passes over the heat exchange at the back of the caravan fridge and then exits through the top vent. Therefore its very important that both the bottom vent and top vent are not obstructed. However, there are times when you do want to cover these vents. Namely during winter storage, winter touring, when towing or when you are cleaning the caravan.
Winter Fridge Vent Covers for Caravans and Motorhomes
Winter vent covers for caravan or motorhome 3-way fridges are also sometimes referred to as blanking covers. They essentially reduce the ventilation behind the back of the fridge and around the heat exchangers. They are primarily used during the colder winter months. However, there are a couple of other times of the year when you might want to use them. Below is a quick video on how to fit fridge vent winter covers.
So now I’ll discuss when and why you may want to fit caravan fridge winter vent covers. I say ‘may’ because I know from talking to our guests there are some people that don’t own winter vent covers or just never fit them. Do you ‘have to’ fit fridge winter vent covers. I’ve not read the warranty terms for every 3-way Dometic or Thetford fridge, but I don’t believe its a condition. However, the reasons below are why you might want to consider fitting them.
Caravans in Winter Storage and Fridge Vent Covers
Its generally recommended in the leisure industry if you have a 3-way absorption fridge/freezer to fit vent covers while in storage. Now some people state the reason is to stop insects finding a winter home etc. However, that’s not a reason I would give. Namely for the fact that these covers don’t completely cover the vent, hence it really makes no difference for insects etc. The reason I think fridge vent covers should be on your winter checklist is they can reduce driving rain and snow ingress.
The standard summer vent has titled slats so rain runs down and not into the van. However, over the winter months with higher wind speeds, you can get driving rain and snow. Hence, rain and snow hitting the van from the side. With just the standard summer fridge vent in place, more of that rain/snow will get through the fridge vent. This will accelerate corrosion of the pipes and heat exchanger. There is also electrics behind there to think about. So its a good idea to fit winter fridge vent covers to reduce the effects of driving rain/snow over the winter months.
Fitting Winter Fridge Covers When Using the Fridge During the Winter Months
The second scenario when you might want to fit caravan fridge winter vent covers is if you actually want to use your fridge over the winter months. Dometic and Thetford advise fitting fridge winter vent covers when the outside air temperature is below 10 and 8 degrees celcius respectively. Why? Well, its to do with helping to the fridge to operate effectively and efficiently. As I stated above, and absorption fridge works by pulling heat from inside the fridge and transferring that energy into the outside environment. And the principle of how the heat exchangers work is on a temperature difference. If the temperature difference between the heat exchanger and the outside air temperature is not significant enough then the fridge will either not work efficiently or will not work at all.
Hence, what fitting the winter vent covers does is reduce the amount of cold air passing over the heat exchanger. Therefore, the purpose is to try and maintain a temperature difference between the heat exchanger and the outside air to transfer the heat energy from inside the fridge to the outside environment. If it is windy the improvement in fridge/freezer performance once the winter vent covers are fitted can be even more significant. However, I have had guests in the past who have never fitted winter vent covers and have stated their fridge has stayed working just fine. Each to their own, but the manufacturers state they may be needed when the outside air temperature is below 10 degrees Celcius.
Fitting Fridge Vent Covers While Towing
Whether its winter or summer, if you have your caravan fridge running from the 12V supply from your tow car while towing you may want to consider fitting the fridge vent covers. Why? Well, let’s imagine you are on the motorway. Therefore there is a lot of air flowing over the fridge vents, equivalent to a windy day. Hence, there may not be that temperature difference around the heat exchange for the fridge to work effectively. Fitting the fridge vent covers while towing will reduce the amount of ventilation and help to maintain the temperature difference for the heat exchanger to work effectively.
While I’m on the topic, you may want to read my post on fridge problems while towing with modern Euro 6 engine tow cars. There are reports of tow cars with modern engines failing to provide sufficient 12V power to keep 3-way caravan fridges working properly.
Fitting Fridge Vent Covers When Cleaning Your Caravan
As I discuss in my post on how to clean a caravan or how to clean a motorhome you never want to use a pressure washer. Though its reasonable to want to use a hosepipe when cleaning. However, you never want to spray water directly at the fridge vents. As stated above, a reason you may want to fit fridge vent covers during winter is to protect from driving rain or snow. Therefore, a similar logic applies to fitting fridge vent covers while you are cleaning the caravan or motorhome just in case you accidentally did aim the hosepipe at the fridge vents.
Caravan Fridge Vent Summer Upgrades
If the outside air temperature is above 8-10 degrees celsius you don’t want to turn the fridge on with winter covers in place (except maybe when towing) as it will reduce the performance of the fridge. However, there are circumstances during very hot summer days when the performance of the fridge may also suffer. If there are high ambient air temperatures the heat exchange can find it hard to exchange its energy into the outside environment. Therefore, the solution to this problem is to increase ventilation with a small 12V fan.
Official Thetford Fridge Ventilator Kit
Dometic doesn’t currently appear to offer an official ventilation fan kit for their 3-way fridges for caravans and motorhomes. However, Thetford does offer an official fan ventilation kit which can be seen in the image below. I have found quite a good video on how to install this Thetford Ventilator Kit. Unfortunately, I’m currently unable to embed the video into this post, but you can watch it through this link. After watching the video I would describe it as a reasonably straight forward DIY task.
If you want to improve the cooling and freezing performance of your 3-way fridge/freezer on warm hot summers days you may want to consider this fridge ventilator kit: Image – Amazon
While Dometic don’t currently appear to produce an official ventilator kit for their 3-way fridges, it might be possible to use the Thetford ventilator kit. The wiring would require a bit of modification, but at the end of the day, its just a 12V fan, thermoswitch and on/off switch. However, that’s also why for the content of the Thetford ventilator kit at around £50 some people want to go the complete DIY route, and source their own fans etc.
DIY Fridge Ventilator Kit
So if you are comfortable with DIY and you want to go the full route of sourcing your own 12V fans you should probably watch the video below from Dan Trudgian. Dan sources some desktop PC cooling fans which are a good choice for this particular application. However, as Dan states in his video and I agree with him, the three fans he has chosen are a bit of an overkill for the additional ventilation required. Though you never know, in the coming years/decades you may need such a ventilation solution if we keep getting hotter summer temperatures!
Conclusions on Caravan Fridge Vents in Winter and Summer
So I hope if you didn’t already know what your 3-way fridge vents were for you now know. I also hope I’ve been able to provide you with a bit more information on why and when you may want to consider fitting fridge vent covers. Not only during winter storage and winter fridge use but also while towing or washing your caravan. Finally, if you have been experiencing poor 3-way fridge or freezer performance in the summer you may need to look into a fan ventilator as shown above. You may also be interested in my post on 2-way compressor fridges vs 3-way absorption fridges.
Anyway, thanks for reading. I also hope in the near future you consider coming to visit us here at Horton Common to experience our expansive views over the Staffordshire Moorlands and Peak District National Park. Furthermore, to try out our rather unique fully serviced pitches. 🙂