Build a performant DIY portable air conditioner (ICE POWERED)

[YouCanDoIt]

Hello to all,
this sound like a stupid question, but I'm stuck on this from several days and I had no other chance than ask for help.
I want to buy this 100mm Dryer flexible Vent Hose and I need to connect to my 4 inches (102mm) SEAFLOW blower fan:



As you can see the diameter of my fan is 2mm more than the vent hose diameter and to complicate things, there is some sort of 10mm thread which probably expand diameter to 105mm (there is a label with printed INTAKE: 4" (105mm)).

This is how the same fan should look once connected (taken from an existing project I'm using as inspiration):


Here is where the 4" duct flex in the above sample has been purchased. I can't find any details or diagrams in the product link, but description clearly states that diameter is 4 inches (102mm).

My main concern is that the duct I want to buy is 100mm and not 102mm.
I never had chances to play with flexible Vent Hoses and I'm wondering if their diameter can be stretched to connect to a pipe of about a couple of mm more larger diameter. From the sample seems possible (otherwise it wouldn't connect to a 105mm intake), but the duct I want to buy is from a different brand and I'm not sure it has the same expansion capacity (mine is 4-layer thickness while that one 3-layer thickness and the 2 missing millimetres in diameter increase my concerns).

Many thanks

Edit: This thread evolved with many useful information and ideas. So I changed the title from "I need to connect a 100mm Dryer flexible Vent Hose to a 102mm pipe" into "Build a performant DIY portable air conditioner"
Below is a (not definitive) diagram that shows how should be. The processing unit is detachable meaning that the ice chest can also be used as originally was designed for (ex: picnics).
WARNING! IF YOU ARE GOING TO FREEZE THE ICE PACKS THROUGH A FREEZER AND THE FREEZER IS LOCATED IN THE SAME ROOM YOU WANT TO COOL, THIS DIY PORTABLE AIR CONDITIONER WILL NOT WORK.
More details here. Many thanks to IanB for this and many other contributions to the thread!

[IanB]

I would guess it may not fit. You would prefer a flexible hose with a 4 inch (102 mm) inside diameter.

The hose you linked to is made of thermoplastic material (good for stretching), but it is lined with aluminum foil and steel wire reinforcement (not stretchy).

If the hose was only made from plastic you could likely warm it up with a heat gun and stretch it over the fan connection. However, with aluminum and steel wire in the construction I don't know if it would stretch so well. It seems like a gamble.

[rich t]

The steel wire is a spiral...

So if you can twist the hose a bit, you can make it (a bit) larger or smaller, depending on if you twist with (smaller) or against (larger) the spiral...

The hose also gets wider if you unstretch it -- i.e., compress all the spiral rounds together -- its nominal diameter is when it is nominally stretched -- it naturally gets to be a larger diameter when unstretched/compressed.

[NiHaoMike]

Tolerances on flex ducts are quite loose, 2% isn't going to be a problem.

[Dundarave]

Try googling “dryer duct connector” and your location.  There might be an available solution that will either solve the issue, or provide you with the parts to cobble up a solid solution.

[themadhippy]

Been there many times,some its a right battle,others just fall on.The method ive found best is to stand the fan up on a solid surface,compress the pipe as much as possible and stretch  it down whilst twisting it onto the fan boss

[Psi]

I've 3D printed adaptors for fan/air ducting before, worked well.
Used one to get my floor mount solder fume extractor outputs to fit onto the extractor tubes running to the desk.

[BILLPOD]

Good Morning Psi, I've heard that flexible dryer vent pipe is horrible, since there is not a 'smooth' flow of drier exhaust, and they get filled up with lint and are very difficult to clean out.   Try to get some solid vent pipe, (mine is 4"aluminum).
It also would be easier to fasten to your booster.

[mr ed]

Dryer duct should be metal, not any plastic. Plastic is a fire hazard, more so with lint.

[NiHaoMike]

Aren't vented electric dryers obsolete? All the high efficiency dryers I see nowadays are ventless heat pump.

I don't think this is for a dryer, but something else that needs venting.

[YouCanDoIt]

Many thanks to all for the numerous responses and sorry for my delay, but I wanted to wait for the seller response. He told me that it can be stretched to 102mm. However I made him aware that with the intake becomes 105mm. He'll manually check stretchability directly in the warehouse and will let me know.

I would guess it may not fit. You would prefer a flexible hose with a 4 inch (102 mm) inside diameter.

The hose you linked to is made of thermoplastic material (good for stretching), but it is lined with aluminum foil and steel wire reinforcement (not stretchy).

If the hose was only made from plastic you could likely warm it up with a heat gun and stretch it over the fan connection. However, with aluminum and steel wire in the construction I don't know if it would stretch so well. It seems like a gamble.

Most of the flexible hose are 4 inch in size and I'm surprised this one has such strange diameter. I have chosen this one because seems to be of the best quality (4 layer Thickness).

I'm not sure about each layer thickness, but in theory, If I can remove one or more layers I should be fine.
By looking at similar products it seems possible and steel wire is around 1mm:


Thanks for heat gun tip, this should be of great help when dealing with very little tolerance.

The steel wire is a spiral...

So if you can twist the hose a bit, you can make it (a bit) larger or smaller, depending on if you twist with (smaller) or against (larger) the spiral...

The hose also gets wider if you unstretch it -- i.e., compress all the spiral rounds together -- its nominal diameter is when it is nominally stretched -- it naturally gets to be a larger diameter when unstretched/compressed.

Many thanks. I think that the photo above should represent the result after your technique applied.

Tolerances on flex ducts are quite loose, 2% isn't going to be a problem.

With the intake becomes 5%, but I hope I can remove the layers or, even better, the technique suggested from rich t.

Try googling “dryer duct connector” and your location.  There might be an available solution that will either solve the issue, or provide you with the parts to cobble up a solid solution.

Yes, that was what I tried when I saw this potential problem. On AE I didn't found anything about "100mm to 102mm" and elsewhere I found the opposite. However there are very cheap joiners which are 100mm on both the sides and given that the internal dimensions of the fan is exactly 100mm, I could do the connection as is directly from within the inside. Maybe some hot glue to seal it well.

Been there many times,some its a right battle,others just fall on.The method ive found best is to stand the fan up on a solid surface,compress the pipe as much as possible and stretch  it down whilst twisting it onto the fan boss

Thanks for the precious information. In fact I was having no idea on how would have been the best way to attach the hose without breaking it.

I've 3D printed adaptors for fan/air ducting before, worked well.
Used one to get my floor mount solder fume extractor outputs to fit onto the extractor tubes running to the desk.

A 3D printer! This is for sure something that soon or later I will have to add to my arsenal!

Good Morning Psi, I've heard that flexible dryer vent pipe is horrible, since there is not a 'smooth' flow of drier exhaust, and they get filled up with lint and are very difficult to clean out.   Try to get some solid vent pipe, (mine is 4"aluminum).
It also would be easier to fasten to your booster.

I'm surprised about this and I really need to check better before I buy.
This is a portable DIY air conditioner. What the fan does is suck cold air from a radiator placed inside a container. it is partially based on design. I'm not sure on what could be better for this kind of applications, but all the projects I saw uses flexible dryer vent pipe.
In this specific application, keeping the air cold and a very low noise is important, so I'm not sure if a solid aluminium vent pipe is suitable. What you think?
I'm not sure if there is the risk of lint, but the length of the hose is 5 meters. If cleaning becomes harder I can just replace with a new cut.
The not 'smooth' flow you're talking about is for sure a concern. Do you mean this translate in a reduced range of blowed air?

Dryer duct should be metal, not any plastic. Plastic is a fire hazard, more so with lint.

I'm not sure if there are such risks in my specific application. Every device in my home is made of plastic just like the portable conditioner I'm building. Probably you're talking about fireplaces or fume extractor in the kitchens.
What about silicone tubes used for intercoolers?

Aren't vented electric dryers obsolete? All the high efficiency dryers I see nowadays are ventless heat pump.

I don't think this is for a dryer, but something else that needs venting.

Yes, this is not for a dryer. I'm building a . I don't think ventless heat pump can be of any help in this kind of project.

[YouCanDoIt]

Guys, I see that you're all very experienced about blower fans. Unfortunately the connection with the hose is not the only one problem I'm facing.
I want to regulate speed based on the detected ambient temperature, but this fan is only 2 wires while the controllers are designed for 3-4 wires PWM fans.
If you want to help me, I have an open thread on this and no one has been able to help me (link).
I hope to complete this project as soon as possible (here is nearly 35C°) and before september (when will be useless).
Thanks
 

[DTJ]

Grab a short 50mm long bit of 100mm or close to DWV (drain waste vent) or storm water pipe. Make a cut in the wall and insert it into the end of the fan housing. Glue it in place. It will provide a smaller OD to slip your vent pipe onto.

[zapta]

If you don't have access to a 3D printer, you can use an online service such as this https://jlc3dp.com/3d-printing-quote

[YouCanDoIt]

The seller responded to me and said that it cannot be stretched. I really appreciate his honesty. No further info, but I suppose unstretchability is due to steel and aluminum layers.

If you don't have access to a 3D printer, you can use an online service such as this https://jlc3dp.com/3d-printing-quote

I'm afraid between the cost of the service, shipping costs, time to edit the project etc it doesn't worth, but thanks anyway.

Grab a short 50mm long bit of 100mm or close to DWV (drain waste vent) or storm water pipe.

I've not been able to find any DWV or storm water pipe in AE. May be I used the wrong search terms? Perhaps some sort of very hard rubber? This one should be easy to find (edit: no, not easy to find at all).

Make a cut in the wall and insert it into the end of the fan housing. Glue it in place. It will provide a smaller OD to slip your vent pipe onto.

Not sure if I've understood well, but I suppose the cut to the wall is to facilitate the hookup into the internal 100mm diameter of the fan. I like your idea, but does not seems easy to find such product with the required diameter. The closest I have been able to find is this plastic joiner:


The valve should be easy removable, but there is inside a ring that slows down the air flux. Also, with a solution like that, the internal diameter of the fan will be reduced. I still hope for a solution that works externally and leave the internal working area free.
This is an approach that I would prefer to stick as the last resort. I still hope I can remove the offending layers and directly plug the hose like in the linked youtube video.

BILLPOD  has done some good observations   about the cons of flexible vent hoses. Not sure how many points apply in my specific case, but the absence of a 'smooth' flow for sure.
I'm trying to understand if silicone tubes used for intercoolers like the one I posted above perform better for noise reduction, temperature insulation and air flow. They are also available with 102mm ID and from what I see they are much easier to fasten. Someone expert may want to tell me what could be the downsides. There must be a reason if all of the portable DIY conditioners I had chance to check only use such flexible vent hoses.

[kripton2035]

this : https://www.thingiverse.com/thing:1950864
and a good large enough 3d printer and you can make all the adaptors you need.

[IanB]

I've not been able to find any DWV or storm water pipe in AE.

Actually, this sort of thing you would find in a local hardware store.

[YouCanDoIt]

this : https://www.thingiverse.com/thing:1950864
and a good large enough 3d printer and you can make all the adaptors you need.

I've not been able to find any DWV or storm water pipe in AE.

Actually, this sort of thing you would find in a local hardware store.

Thanks guys, but I think I will go with the silicon hose I posted above. It doesn't need any adapter and I have reasons to believe that perform much better than a flexible hose. I just want to see what people have to say and if this could be the best solution for my specific project.

[YouCanDoIt]

Guys, I think that people reading this thread will end up with wrong informations (especially from side).

It has been said that solid ducts are better than flexible ones, but this not applies to all applications especially mine.
I was going to do the mistake to buy a silicone hose:


The main disadvantage is that, unlike flexible hoses, there is no noise reduction and this make them unsuitable for applications like mine (and explains why I see no design using solid ducts). And there is no way to reduce noise in a solid duct.
There is a discussion about Flex vs Solid and below I quote some of the most interesting statements:

• Sound insulation is installed inside of the duct and would not have to be removed to seal the ductwork. Exterior insulation will not help on sound.
• Flex branch ducts will reduce the sound level.
• Exterior duct insulation will do little to dampen the noise as it reflects off of the hard surfaces inside of the metal duct. The flex duct branches will dampen the noise. There should be no bearing noise. (Low pitched growling sound.)
• most of those systems are high static, and the high static is the reason for the noise. flex duct work is the quietest duct. as far as duct work noise goes.

I've also been told that with a flexible hose I am free to decide the exhaust length and the more is the length, the more is noise reduction.

I resume here some good points raised from users about flexible hoes for which I don't see any concern:

Dryer duct should be metal, not any plastic. Plastic is a fire hazard, more so with lint.

It depends from the application. In a portable conditioner there is no fire hazard risk. For other application (kitchen fumes extractors etc) most of the flexible hoses in the market (included the one in this thread) are flame resistant.

Good Morning Psi, I've heard that flexible dryer vent pipe is horrible, since there is not a 'smooth' flow of drier exhaust, and they get filled up with lint and are very difficult to clean out.   Try to get some solid vent pipe, (mine is 4"aluminum).
It also would be easier to fasten to your booster.

The lack of 'smooth' flow is what probably contribute to noise reduction. In the youtube sample I posted there are no issues in that matter. if there are applications that need to deal with lint, I would say it would be much easier to just replace with a new cut (flex hoses available in the market are normally several meters in length).
Fastening is easy just like flexible ones, mine is just a rare case of unmatching diameter.

So, unless someone has valid reasons for using a solid hose for this specific case, I'm going to buy the flexible one and the same may want to do users that work with systems that have the same requirements.

[IanB]

You will find that ducting is a bit like wiring. Rigid ducts tend to be used for fixed installations with mounting brackets, and often inside walls or ceiling voids. Flexible ducts are typically used to cross open spaces, where some movement may need to be accommodated, and where it is not a fixed installation.

As far as the noise is concerned, noise levels depend heavily on the flow velocity. With low flow velocities the noise may just be a whisper.

Another consideration is that flexible hose might have a higher pressure drop due to the lack of smoothness on the inside. So flexible hose would be more suitable for short runs rather than longer runs.

There are so many variables that you will have to decide based on your knowledge of the details.

[YouCanDoIt]

You will find that ducting is a bit like wiring. Rigid ducts tend to be used for fixed installations with mounting brackets, and often inside walls or ceiling voids. Flexible ducts are typically used to cross open spaces, where some movement may need to be accommodated, and where it is not a fixed installation.

As far as the noise is concerned, noise levels depend heavily on the flow velocity. With low flow velocities the noise may just be a whisper.

Another consideration is that flexible hose might have a higher pressure drop due to the lack of smoothness on the inside. So flexible hose would be more suitable for short runs rather than longer runs.

There are so many variables that you will have to decide based on your knowledge of the details.

Many thanks for your response. It contains very useful tips that help to identify the more suitable duct for specific conditions.
Based on your tips, to me the flexible one seems to be the more appropriate:

• Noise level: it's a 270CFM blower fan, so I think velocity is pretty high. From the video the noise does not seem too much, but it's still a boring noise.
• The right side connection is short and fixed. The left side longer and flexibility is needed to output air to the desired direction (not sure why it has been used a pipe reducer adaptor, may be to create more pressure and get a longer range)

Honestly I'm still tempted from the silicon one. It has the same diameter of the fan and don't need any adapter, but I'm still concerned about noise and thermal insulation (I feel like the flexible one can isolate cold air flux better from heat).

What you would choose if you were me?

[IanB]

Based on the video, thermal insulation is a non-issue. The goal is to cool the surrounding area, so you want the cold to escape. That is the whole point of a cooling device.

The majority of any noise is going to come from the fan/blower unit. The ducting has little to do with it, especially with the short lengths in the video. (The noise comes from the motor and the whirring blades of the fan. For less noise, you need bigger, slower moving fan blades.)

Based on the video images, I would go with flexible stuff similar to what was shown there. If only because it will be easier to work with.

That said, it is not the design I would build. I would mount (something like) a car radiator on top of the ice box, and would pump the cold water through that. I would then place a normal room fan to blow (or pull) air through the radiator. The room fan will be quieter, and will give a softer, more gentle breeze of cool air. Perhaps use a box fan to pull air through (fans are generally better at pulling than pushing).

(Search for "box fan" to see what I mean. They are big, square fans that could be mounted up against a radiator of similar size and shape.)

[YouCanDoIt]

IanB, you really know what you're talking about!

The majority of any noise is going to come from the fan/blower unit. The ducting has little to do with it, especially with the short lengths in the video. (The noise comes from the motor and the whirring blades of the fan. For less noise, you need bigger, slower moving fan blades.)

Yes, it seems to come from the motor itself.
I have read the same tips under the comments of this other design:


Here noise seems much more noticeable (same ice chest and radiator), but I'm not sure if it is due to a smaller blower (3" 130CFM) and/or the duct made of just one aluminium layer. So, I preferred a 4" 270CFM blower + 4 layer flexible duct combo. The guy that made the build stated that a longer exit tube also contribute to noise reduction. The flexible duct is 5 meters long and can be cut into pieces.

Based on the video images, I would go with flexible stuff similar to what was shown there. If only because it will be easier to work with.

Well, the black silicone solid duct shown above should fit as is because diameter is exactly 102mm, just like the fan. The flexible duct is 100mm and probably I will have to use some adapter if there is not enough tolerance. However, a solid one needs the fan kept at a specific height point, so I will end up with some adaptor anyway. The flexible hose goes straight into the blower intake, so probably it will not make difference whether it is solid or not. Probably I'm better off with a flexible one since I can also get from it a second cut for a directional exit tube which, at least from what said the guy, can help to reduce noise. If there is some noise coming from the hose (which we cannot detect just by looking a video), it will be impossible to fix when the hose is solid.

I'm in doubt about the exit tube on the video. Except the ability to change flow direction, I'm not sure if there are other benefits or even drawbacks when diameter is reduced in such a way. Perhaps a smaller diameter create more pressure resulting in a longer range, but to me that seems only useful for outdoor use to target the specific area where people are located. In this case a longer range could ensure the whole area is constantly cooled. On a closed room the cold is going to expand anyway.

That said, it is not the design I would build. I would mount (something like) a car radiator on top of the ice box, and would pump the cold water through that. I would then place a normal room fan to blow (or pull) air through the radiator. The room fan will be quieter, and will give a softer, more gentle breeze of cool air. Perhaps use a box fan to pull air through (fans are generally better at pulling than pushing).

(Search for "box fan" to see what I mean. They are big, square fans that could be mounted up against a radiator of similar size and shape.)

I'm very glad to see that I am not the only one that thought the same. In fact my design is very similar to what you described, but given that I saw no implementation anywhere I asked myself if would have been a mistake.
This is the 8 rows car radiator I have already purchased:

There are basically two containers. The first one is a 52QT rotomolded ice chest (advertised ice retention is 6 days) and its main purpose is to keep water cooled through gel ice packs (which seem to last much longer than regular ice packs). On top of it a second (and much smaller) styrofoam box where all the work is done. Inside of it the radiator and the water pump (blower fan is attached on the top). The containers are connected through two small 10mm holes corresponding to the inlet and outlet of the radiator. In this way the heat has no chance to penetrate. It also allows me to detach the top container and use the ice chest box as originally was designed for.

I thought to the box fan, but I've read is bad design because generates heat. On a room does not make much difference, but on a small container the heat easily accumulate. Yes, it is much quieter and with a one big enough to cover a radiator like mine the noise could be even unnoticeable. However this means a much less output. From what I have understood, this is more intended as a fan that emits gentle breeze of cool air, but it will not work to decrease room temperature like does a regular air conditioner.
Anyway, given that my design is made of two separate containers, I asked myself if adding an helper box fan can help. As you see the blower fan will only be able to target a small area of the radiator. I will keep the radiator attached to the top wall through a gasket (probably made of styrofoam) in order to create more pressure and suck from a larger area, but I'm still wondering if a secondary box fan pushing air against the radiator can help. This is probably something I should evaluate later once I see how much is large the area covered by the blower.
Pheraps I should try to keep the container as small as possible not only for general space saving, but mainly because I assume the smaller is the container the more pressure is generated resulting in a larger sucked area from the radiator. Is this correct?

Last thing...the linked youtube project is the only one that uses two air intake and I suspect because of the very small volume available to the blower after the lid insulation. In my case I suppose I should also try to reduce volume as more as possible, but the radiator is much larger. Do you recommend one or two air intake?

[IanB]

My idea is not to put the radiator inside the ice chest, but rather to stand it upright in the open air on top of the chest. The box fan is then mounted against the radiator, also in the open air. The box fan by itself would just move air through the room, like any room fan. When you place the radiator next to the fan, the fan will suck air through the radiator, and will then move the cooled air around the room.

The water pump will simply take cold water from the reservoir, pump it through the radiator, and return it to the reservoir.

I see very little to be gained by putting the heat exchanger inside the cool box and then sending air through small ducts in and out of the box. The air is in the room, the cold is inside the box. We want to bring the cold out of the box, not send the air into the box.

See the video below, and others like it, for inspiration. In that video Matthias is sucking air through a filter, but here we want to suck air through the radiator instead.

[YouCanDoIt]

My idea is not to put the radiator inside the ice chest, but rather to stand it upright in the open air on top of the chest. The box fan is then mounted against the radiator, also in the open air. The box fan by itself would just move air through the room, like any room fan. When you place the radiator next to the fan, the fan will suck air through the radiator, and will then move the cooled air around the room.

Oh, now I understand. Well, I have considered such design at the beginning, but I ended up with the motor blower one once I saw the limitations (some are just my deductions and I could be wrong):

• A radiator kept in the open air will absorb the heat from the room resulting in an air flow less cold.
• Condensation may occur and if severe can block the radiator or the airflow in a noticeable way. I'm not sure if this phenomena has more chance to occur outside or not, but I suppose that when inside a container it will be easier to take over it. With a motor fan, the airflow through the radiator should be stronger and less subject to these issues.
• Condensation generates water that drops on the floor. Nothing that can't be solved with a basket, but a container is more convenient because also act as a drops collector.

It seems that a motor blower is able to generate the coldest air temps, at least said so the same guy above who also built a couple of box fan projects:
.

Unless I'm missing something, instruments also seems to confirm such statement:


I believe that in all of its projects the fan is positioned in the way you described (radiator next to the fan in order to suck air through the radiator). You have to consider that the design in the photo uses a less powerful motor combined with a very cheap small radiator.
The issue with a box fan is if you keep it insulated inside a container it still generates lot of heat. You solve this problem if you remove the insulating container like the project above, but at this point the radiator is exposed to the heat of the room and some of the cold is lost in the road. This should have a much bigger impact compared to the heat introduced in a cold container through an air intake.

I'm not sure if such designs are able to change a room temperature especially when temps are very high. From what I have understood, they seem more suitable to get some gentle breeze of cool air while sleeping given that they are practically free from noise. I was going to buy this air cooler, but I had to realize that they just don't work and opted to build my own. Of course those are very cheap coolers that have nothing to do with the ones we see here, but the basic design is the same.
The same guy posted a video showing that he was able to drop room temperature by 10F from 85F, but he had to use a 16 row radiator combined with a gigantic and powerful 0.5 meter fan. This one really makes lot of noise and what about higher temps like 95F?

I see very little to be gained by putting the heat exchanger inside the cool box and then sending air through small ducts in and out of the box. The air is in the room, the cold is inside the box. We want to bring the cold out of the box, not send the air into the box.

See the video below, and others like it, for inspiration. In that video Matthias is sucking air through a filter, but here we want to suck air through the radiator instead.

Yes, we want to bring the cold out of the box and, most of all, preserve its temp by keeping it far from any heat source (and the radiator should also be kept away from any heat source). This is the main reason for which I designed two separated containers, but I think I have not explained well if you think the small ducts are for sending air.
With the regular design (everything processed inside the ice chest box) we have to make 1-2 big holes for air intake, plus another one for the blower. Insulation is totally broken in such a way and we can only partially mitigate the issue because the air has to enter in some way. That's why to me seemed much better to leave the ice chest box totally insulated (apart two small 12mm holes used for the communication).
This diagram should give you a better idea (elements are not proportional, but I can only use Paint 3D now):


Top container (styrofoam): 1 or 2 air intakes + blower motor + water pump + radiator + (perhaps) 1-2 gel ice packs (to reduce heat introduced from the air intake/s)
Bottom container (ice chest): gel ice packs submerged in water

The two containers are connected through the twos pipes you see on the right side. The one to the left push the water exiting from the radiator outlet. The one to the right sucks the cold water which is pushed to the radiator through the water pump inlet. There is no air circulation between the containers, just the water and the whole thing is processed in the same way of the "all-in-one" common designs.
The two pipes are connected to the bottom container through quick release pneumatic fittings. This allows me to quickly detach the small container and use the ice chest box as was originally designed for (storage for cold drinks etc).

The reasons for which I'm reluctant to remove the top container and leave the related parts exposed are multiple:

• without the thermal insulation provided by the box, the radiator and all the working parts are exposed to the heat
• More complicated work to join all the pieces together
• Parts can easily get damaged during transport.
• I feel that without a container the blower will suck a much smaller area from the radiator due to the lack of pressure (probably no more than the fan diameter)

My main concern is the heat introduced by the air intake. This is unavoidable because required by the blower motor. I have read that there are several tricks available to reduce the heat, but I have not yet investigated. Do you have something to recommend?

So, now that you should have a clear idea of my design, do you see any flaw?

Adding a box fan could be useless. May be that the blower motor itself is enough to get all the available cold from the radiator, but this is something that I will only know in the field.

Thanks for the video. It's a bit difficult to get an idea because the project has a completely different purpose and use parts that are unrelated for the kind of project I'm building. However, what I saw is the same I previously talked about: the necessity to use much bigger parts included a gigantic fan in order to make things work.
I see so many of such videos before going with the blower motor. Many people that tried both the approaches are against the box fan, but many other people are in favour. It's very hard to understand what is better because there are too many variables and what does not work for someone it could be simply due to some flaws in the design.
Blower motor design is what seemed to me to give more chances of success along with easiness construction and more portability, but I could be perfectly wrong on the cooling performance.
I'm afraid is too late for me to change design because I have already the fan and I certainly don't want to lose the money I had to spend. Frankly speaking, I'm glad to not have the option to change design because this would mean returning back to beginning when I had to do long and very stressful researches.