Custom Air Conditioning Retrofit

[Brian B-P]

Originally Posted by ReagentGrade

Perhaps they would be willing to do some the following:
1. extend the bumper slightly, move the spare over, and install a mounting plate for the condenser
...

While this makes sense, it would probably be tough to convince Escape, because it would mean longer rear frame rails. The frame is made by an outside supplier (specifically for Escape), who probably does them in batches for efficiency and may use a fixture to hold the parts; a custom length would not likely fit into that production process very well.

It might also make sense to avoid extending the bumper, because that would restrict the departure angle and would make the corners stick out unnecessarily (because the whole width of the bumper would move back, even though only the width of the air conditioning unit is needed). An air conditioner unit mounted on top of the frame and bumper (the frame and bumper are at the same level) could be protected by a loop of steel tubing just around the mounting platform. The loop and platform could be added later by the owner. I think I would prefer a bolt-on installation for post-manufacturing additions, rather than welding, due to the expertise needed to properly weld the T1 alloy steel (probably ASTM A514, as per previous discussions) used for the frame.

It might be easier to get Escape to just shift the spare. I think it's also worth considering mounting the spare under the floor, between the frame rails, to get it entirely out of the way and to shift mass forward for stability. I'm sure that would be an owner modification; perhaps Escape would be willing to leave the stock spare mount off entirely, with the spare carried in the tug.

[rubicon327]

ReagentGrade,
Glad to see the excitement. My hope by documenting it was to inspire others as to what might be possible. I can't speak to what ETI will or will not do, but it is certainly worth asking. Here are a couple of thoughts that piggybacks off of some of what Brian B-P has already added:

1. extend the bumper slightly, move the spare over, and install a mounting plate for the condenser
If ETI won't do it, this can be easily accomplished by enlisting a skilled welder. That might be better anyway because it would be done exactly how you want it and it avoids the time and energy of communicating back and forth with ETI. Additionally, they would have very little chance of getting it right without the actual condenser in hand and they are probably not going to want to handle equipment they aren't actually installing.

2. stub out the two 120V drops (the inside unit could extend from the roof top A/C wiring)
The traditional 120V circuit only needs to go to the outdoor unit from a 15 amp breaker in the power center. From the looks of it the power center is in the rear dinette area of the 5.0 TA so that makes it simple. ETI does "A/C ready" installs so I'd think they would work with you on this. If ETI installed the breaker and left the wire looped in the lower dinette storage area that is really all you would need. Then you take it through the floor and out to the condenser in some flexible Liquidtite conduit. The indoor unit uses a combination 4 conductor power and control wire fed from the outdoor unit.
www.highseer.com/4-lead-wire.html

3. install the digital thermostat with appropriate wiring
Nothing needs to be done in this regard. The unit comes standard with a wireless remote control.

4. adapt the shelf over the dinette to accommodate the dimensions of the air handler
If the shelf is standard this may make the mounting easier than modifying a cabinet like I did but you should keep in mind that you want to conceal all the horizontal piping (2 refrigerant lines and drain) and the combination power/control wire. I would think a cabinet with modified opening would be best. Just make sure nothing else would be in your way (i.e. it looks like speakers are mounted on the face of the back cabinet as part of the stereo option)

5. run the control wiring, copper lines, and condensate tube
Again, only a small gauge combination power/control wire is needed from the outdoor unit to the indoor unit. Maybe they would route it from the upper cabinet to the lower dinette storage area and you could take it outside from there in Liquidtite. It would be great if they would route the pre-insulated refrigerant line set and drain for you from the upper cabinet to the lower dinette seating storage area but then again this is kind of tricky without knowing EXACTLY how it needs to be routed and terminated. Mine is routed behind the corner panels on each side and it isn't perfect, but acceptable. The corner panel with the A/C lines bulges out a bit. Would be better if I cut away the wall liner and fit them tighter to the shell.

[ttseeker]

Would the optional underside spray in insulation be in the way of this installation?

[Duer]

I also have an engineering background and totally agree with what you're trying to achieve.
I'm considering order a new 17B but don't want the noise of the AC plus additional weight.
Also, but aside from your original consideration is the CofG moment that will be considerable
reduces by taking the weight off the roof and placing it in a much improved location.
Aviation background dictates the very important weight and balance envelope that no one talks about in the trailer industry...
Fly an airplane that is at it's gross weight but loaded outside it's envelope and presto...major control problems... i.e (back to trailers) the need for sway bars etc to attempt to control an problem that is outside the design envelope of a system...

Duer

[rubicon327]

Originally Posted by ttseeker

Would the optional underside spray in insulation be in the way of this installation?

I'm not sure if the factory spray foam boundaries would extend to the front or rear corner where I would suggest exiting with the piping and wiring (depending on design and layout of system). Even if it did, I would just drill through it and seal around the penetrations. It is a closed cell foam so no issues with any exposed edges, etc. Although I would cut away a small section by hand first to make sure nothing is embedded in the the foam before drilling.

[float5]

Originally Posted by Duer

I also have an engineering background and totally agree with what you're trying to achieve.
I'm considering order a new 17B but don't want the noise of the AC plus additional weight.
Also, but aside from your original consideration is the CofG moment that will be considerable
reduces by taking the weight off the roof and placing it in a much improved location.
Aviation background dictates the very important weight and balance envelope that no one talks about in the trailer industry...
Fly an airplane that is at it's gross weight but loaded outside it's envelope and presto...major control problems... i.e (back to trailers) the need for sway bars etc to attempt to control an problem that is outside the design envelope of a system...

Duer

Well, Escapes, at least ours, do have an airplane door!

[rubicon327]

Originally Posted by ReagentGrade

At some point lithium batteries will become competitive. When Tesla's Gigafactory is fully on line, A/C on solar might be possibile for a high efficiency unit. I'd need more solar panels, but even if I could only use A/C during the day, that would be great.
Technomadia has A/C on solar. Talk about the bleeding edge!

Check out these links. The Australian company Kimberley makes some serious off-road caravans with advanced technology. They are doing exactly what you stated above. 2.2kw (~7500 BTU/H) 12 volt split system air conditioning powered via a 480 Ah lithium battery bank and generous amounts of solar (720W). Expensive for sure, but they've proven it can be done. Also note that they started with downsizing the unit from 3.2kw (~11,000 BTU/H) and have what they call a tropical roof that is insulated and integrates the solar. It sits 2" above the actual fiberglass shell.

Kimberleykruiser - Super Quiet Air-conditioning

The Perfect Lithium 480 Ahr Battery Kube for Off-Road Caravans

World First for off road caravan Tropical Roof

[Terry H]

Wow I am really interested in this unit. Where would you install the main unit on a 5.0TA. Is it under the bench or outside on the modified bumper?

[rubicon327]

Originally Posted by Terry H

Wow I am really interested in this unit. Where would you install the main unit on a 5.0TA. Is it under the bench or outside on the modified bumper?

Terry H are you interested in the Fujitsu mini-split that I installed that was the original basis of the thread or the system that Kimberley is using that was the subject of the previous post to yours? The Kimberley system was more for information only since it may not even be possible to acquire.

[Terry H]

I am interested in anything that doesn't make a lot of noise, a quality product and that works efficiency. Your are right the Kimberley system probably would be hard to get. Do you know what I would have to have Escape set up wire wise, electrical. I have a build sheet that is do soon, so I am up for ideas. Yes I would like to know more about your air conditioner.

[rubicon327]

Originally Posted by Terry H

I am interested in anything that doesn't make a lot of noise, a quality product and that works efficiency. Your are right the Kimberley system probably would be hard to get. Do you know what I would have to have Escape set up wire wise, electrical. I have a build sheet that is do soon, so I am up for ideas. Yes I would like to know more about your air conditioner.

The link is broken in post #1 to the unit I used so here it is again: 9RL2: Entry Level - Wall Mounted - Halcyon™ SINGLE-ROOM SYSTEMS - Residential - FUJITSU GENERAL United States & Canada

I can't stress enough how this has changed the trailer. I know others talk about the newer Dometic digital thermostat and 2 speed fan but I can guarantee you this is much quieter. I suggest reading the whole thread if you haven't already. Especially my post #182 which talks about some specifics as I felt they might apply to a 5.0TA application. The rear cabinet over the dinette is the perfect place for the indoor unit - up high and blowing down the length of the trailer. I have no doubt that it can be done. The question is how much ETI would help or not and how handy you are. I did all my own work except for the startup which was done by a friend who is an HVAC tech. I am willing to answer any questions you have.

Here is a video I found of a guy who did a split system on a Silverado 37QB fifth wheel. He doesn't have a spare tire to contend with on the back but it gives you an idea of how the condenser might be mounted on the rear.

www.youtube.com/watch?v=OUAa5loAUM4&sns=em

[Terry H]

Thank you. I am not tech savoy so will have to really research this and try to find someone in the next two weeks if I am going to go through with it. Wish I could do it but for now guess I will have the roof top model.

[rubicon327]

Reposting here to keep this thread intact. While I was doing the backsplash I used the opportunity to test the mini split heat pump in heating mode since I needed the trailer warm for application. It was about 40F outside and the Fujitsu system easily kept the trailer comfortable at 70F. Runs just as quiet as a small electric heater. It was never intended as a primary heat source as it was really installed for the cooling function, but it will be interesting to see how it does heating the trailer as it gets colder.

[rubicon327]

With the "cold" (not to some of you) temps today we ran a test on the heat pump in heating mode just out of curiosity to see how it would perform. It was about 23F at start of test and 19F by the end as sun had gone down. Over a two hour period the trailer was heated from ~25F up to 60F. I found this quite impressive given that the unit is rated nominal 10,000 BTUH at 47F outdoor temperature and heat pump heating capacity typically drops sharply as it gets colder. This is looking to be quite capable as a secondary heat source if needed when plugged in. Just a reminder to those that may not have followed the thread that this was installed primarily for cooling and the fact that it can heat too is merely a bonus.

Just for information the Fujitsu 9RL2 unit we used can only provide heating operation down to 15F ambient. There are extra low temperature heating models that can heat down to -15F but they are all 208/230V.

[Santiago]

I am a fan of mini splits and don't understand why it has not made inroads in US housing. Room additions and impossible to duct retros I see them but not new construction and that is a shame. The rest of the world uses mini splits and they certainly are efficient and versatile. With more and more housing roof solar panel sales on the way, I can see mini splits making inroads in the US as they are 100% electric and quite capable of extracting heat from ambient air even in the winter to a point as you indicated.

Adding a unit like yours is temping but unit and head still too big for smaller trailers. Hopefully someone will make RV sized ones with a lot of vibration isolation. The Fuji 9K is the smallest I have seen to date but still not RV size in my opinion. I must say this, you and a few others are RV pioneers and will prove what an exciting technology these little air to air heat pumps are. Great job.

[Kevin H]

I am a big fan of mini-splits. While I do not have one in my RV, here are a few pics of a setup I put together to cool my garage/workshop. I had to make it portable as it was a condo and I could not put in a permanent installation. The garage door came down between the head unit on the rack and the outside unit on the flat plate. Plugged it in and put the condensate hose in a Home Depot bucket. Worked great in cooling and de-humidifying in Austin, TX. The versatility of these systems is only limited by your imagination.

[rubicon327]

Originally Posted by Kevin H

I am a big fan of mini-splits. While I do not have one in my RV, here are a few pics of a setup I put together to cool my garage/workshop. I had to make it portable as it was a condo and I could not put in a permanent installation. The garage door came down between the head unit on the rack and the outside unit on the flat plate. Plugged it in and put the condensate hose in a Home Depot bucket. Worked great in cooling and de-humidifying in Austin, TX. The versatility of these systems is only limited by your imagination.

That's a very creative and well constructed setup. I see the unit is Carrier, but can you provide the model? I see on the web they make a couple small 120V models.

[rubicon327]

Originally Posted by Santiago

Adding a unit like yours is temping but unit and head still too big for smaller trailers. Hopefully someone will make RV sized ones with a lot of vibration isolation. The Fuji 9K is the smallest I have seen to date but still not RV size in my opinion. I must say this, you and a few others are RV pioneers and will prove what an exciting technology these little air to air heat pumps are. Great job.

Thanks for the feedback. I realize the size is prohibitive to some, especially on a smaller trailer. I think we made it about as clean inside as you can for a 19 with the indoor unit recessed in the front cabinetry. For the outdoor unit the front tongue worked great but would be tough if you have the front storage box and I realize many do.

What we need is a horizontal compressor arrangement. I did happen to find one rooftop RV unit with DC inverter compressor technology, but not sure of its availability in the US. It is the Aislu MSD. This could be huge as a direct replacement solution for the loud constant speed overhead units that are prevalent. Shows a 9000 BTUH size that is perfect for smaller trailers. Not sure of the particulars, but based on the published noise level of 47 dB it should be much quieter than existing Coleman/Dometic units. Would love to know if anyone happens to have this unit on a North American RV. I did just email the mfr to see if they have US distribution.

Roof top caravan air conditioner

[cpaharley2008]

Does your unit have a back up electric heat? On my unit in my house, Fujitsu they had to run an auxiliary 30 amp circuit for back up electric heat. Once the outdoor unit determines that the outside temperature is too cold for heat transfer, it supplements with electric heat to maintain the set temperature. I can tell when the outdoor unit is not running because the bushes are not moving, but this only happens when it is something like below 32 degrees, otherwise it manages to grab some heat. I remember years ago about heat pumps having to have electric heat backup in case of compressor failure. Also not to play with the thermostat with set backs because if the differential is too great the supplemental heat is activated thus causing an inordinate amount of electric use thereby eliminating the efficiency of the heat pump.

[Kevin H]

Originally Posted by rubicon327

That's a very creative and well constructed setup. I see the unit is Carrier, but can you provide the model? I see on the web they make a couple small 120V models.

Whew! That's a tough one. This was about 13 years ago. I sold the setup when we sold the condo and went fulltime nine years ago. No record. You are correct: it was a 120v unit. I remember it being difficult finding one. They were not widely available at that time.