My Evil Plan

[m.colley]

I wish you had some pics of that install. But I already but a unit ..bummer

Chief,
Here's a couple of pictures I pulled off the ole interweb of the AC install I was telling you about I saw this weekend that gave me my ideas.
This is an interior shot of the install.
The AC is mounted in a upper cabinet on the left in the picture.

Here's a shot of the exterior and what really caught my attention.
.
Notice how flush the outside vent sits, the vent is above the window in this picture. The exterior vent lets the AC discharge all the heat its absorbing to the outside.
I found a similar vent online but I may try contacting the factory that builds Coleman RV's (Dutchmen) and see if its possible to buy the vent that they use.


Martin

[aggie79]

I think that is a "thru-wall" unit rather than a window unit. Window units have an air intake on the side of the case and exhaust out the back. A thru wall unit has the intake and exhaust at the rear only. They are about 2-3 times the cost of a window unit but much less than a rooftop rv unit.

Instead of a vent, what about using a hatch door that you open when you get to the campsite? If I build a CT conversion, this is the route I would go.

[jhamihvfd21]

is this what you are looking for? http://www.amazon.com/LG-Stamped-Alumin ... rough+wall

[chiefairwrench]

wow that is a great solution I wish I knew that before making the decision for a roof top/

[m.colley]

Instead of a vent, what about using a hatch door that you open when you get to the campsite? If I build a CT conversion, this is the route I would go.

I've thought of that as well, and it may be easier to find the right size "hatch" then a grille that I like.

Martin

[wanabxtrm]

m.colley if you haven't already done so I'd encourage you to look into mini splits. I've got some info on my build, as does over the top.

[m.colley]

m.colley if you haven't already done so I'd encourage you to look into mini splits. I've got some info on my build, as does over the top.

I've given mini splits a consideration as well and since the company I work for is a authorized Fujitsu distributor, I can by at wholesale cost. We sell a 9000 & 12000 BTU 115V 16 seer heat pump version and have had really good luck with them. Best part is they only pull 7.5A in cool mode and around 7.7A in heat mode. My biggest concern is the space they take up but there are ways to work around that. I'm still in decision mode on the AC and just looking at different options. I've still got a couple weeks before I start building my cabinets so I've got so time left before making my final decision.

Martin

[chiefairwrench]

Well to little to late for me but given the opportunity I will differently look at A/C differently. I and already y received my roof top Coleman 3Plus with heater I am bummer more comfortable with what your proposing.

[Colemancooler]

I would be very cautious about running a mini split from a generator or inverter an impure or modified sign wave could interfere with the longevity or even proper operation of your mini splits sensitive electronics, not to mention most modern mini splits use variable speed inverter technology to gain efficiency.

[McDave]

Just my .02,
I think you are doing it exactly right. The Coleman Mach A/Cs are tested and true. The rooftop is the most common RV system, Parts are widely available, they are built tuff and are located in the proper place for the most efficient operation as well as out of the way and less likely to be damaged or to cause water damage or mold problems from condensate. My guess is that they have worked through the stress related problems associated with bouncing down the road, and iffy power supply. Domestic A/Cs were never designed for these conditions. I am all for better technology, but I am not sure it is here or ready yet. The last thing I want to do would be to have failures with a system not intended for this purpose, only to find my warranty was void, then having to re-engineer and repair and hope until the next failure. Remember, the unit probably won't fail when you are not using it or don't need it. It will be during 4th of July at the Grand Canyon when nighttime temps drop to around 105f.

Just sayin',
McDave

[flboy]

That system you have a picture of is a window unit build into the cabinet with the exhaust out the back (trailer sidewall). You will notice the vent on the roof (basically a propane refrigerator roof vent).. that allows the unit to draw air in for the side intakes that also usually hang out the window. These systems work fine in smaller trailers and use much less power when on. Theses 5,500 BTU units can be run from a small Honda Generator. It is hard to find a roof unit less than 13,500 BTU roof mount.

The problem with the large roof unit in a small trailer or a roof mount unit in general :

1) The large units cool the smaller spaces <150sq ft. too quick and shut off.... therefore the humidity is not managed well. You are better off with a smaller unit running more often.
2) The 13,5000 BTU roof mount units will require a 30A Service connection.
3 Roof mount units are exposed to the weather and bugs, nesting squirrels and etc.. that will ruin them without even being used.
4) The Sun's UV will ruin the casing and need to be replaced.
5) Repairs more expensive and difficult.


Benefits of the adapted window unit:

1) The unit can be bought at Home Depot or Walmart for ~$150.00, so when they fail... remove them from the cabinet and toss. The roof mount units cost about $900 and when they fail, you need to have take the whole trailer somewhere, pay for a Service Call, or remove it and take it in (a lot of work).
2) They use much less power and can be run with a small generator and a 15A service.
3) For a smaller camper... they will manage humidity much better.
4) The unit is protected from the rain and etc... so the will not deteriorate as quickly/


Note, the use of these smaller AC's should be limited to <150 SQ Ft (trailer 18 to 20 ft max).. else they will not do the job on hot days. I have used them and they work great for smaller trailers. I am building a 7*18 Vnose CTC now and this is what I am going to use (5,500 BTU). You will need to study up some on the proper way to mount in the cabinet to ensure the unit is not drawing air from inside and that it can drain and vent properly. When I install my unit as I build on my current project... viewtopic.php?f=50&t=65498 ... I'll post up details.

Bottom line.. if done properly, I think they are a better and more cost effective choice for a smaller trailer. BTW.. I have used one for 5 years and it has been bouncing around in the camper as I take it off-road and etc... it will not hurt it. I would not be afraid of that in the least. Also, when mounted in a top cabinet by the roof as your picture shows... no different physics in the cooling than a roof mount. It all boils down to how big of a unit do you need to adequately cool. If 5,500 BTU will do it... then a roof mount 13,500 BTU is overkill and actually not going to do as well. I have seen some smaller roof top units ~8,000 BTU... but they still have some of the cons (all but the managing humidity part), are not much cheaper than the larger units... and are slightly too large for a small Honda Generator 2000ui.

[m.colley]

That system you have a picture of is a window unit build into the cabinet with the exhaust out the back (trailer sidewall). You will notice the vent on the roof (basically a propane refrigerator roof vent).. that allows the unit to draw air in for the side intakes that also usually hang out the window. These systems work fine in smaller trailers and use much less power when on. Theses 5,500 BTU units can be run from a small Honda Generator. It is hard to find a roof unit less than 13,500 BTU roof mount.

The problem with the large roof unit in a small trailer or a roof mount unit in general :

1) The large units cool the smaller spaces <150sq ft. too quick and shut off.... therefore the humidity is not managed well. You are better off with a smaller unit running more often.
2) The 13,5000 BTU roof mount units will require a 30A Service connection.
3 Roof mount units are exposed to the weather and bugs, nesting squirrels and etc.. that will ruin them without even being used.
4) The Sun's UV will ruin the casing and need to be replaced.
5) Repairs more expensive and difficult.


Benefits of the adapted window unit:

1) The unit can be bought at Home Depot or Walmart for ~$150.00, so when they fail... remove them from the cabinet and toss. The roof mount units cost about $900 and when they fail, you need to have take the whole trailer somewhere, pay for a Service Call, or remove it and take it in (a lot of work).
2) They use much less power and can be run with a small generator and a 15A service.
3) For a smaller camper... they will manage humidity much better.
4) The unit is protected from the rain and etc... so the will not deteriorate as quickly/


Note, the use of these smaller AC's should be limited to <150 SQ Ft (trailer 18 to 20 ft max).. else they will not do the job on hot days. I have used them and they work great for smaller trailers. I am building a 7*18 Vnose CTC now and this is what I am going to use (5,500 BTU). You will need to study up some on the proper way to mount in the cabinet to ensure the unit is not drawing air from inside and that it can drain and vent properly. When I install my unit as I build on my current project... viewtopic.php?f=50&t=65498 ... I'll post up details.

Bottom line.. if done properly, I think they are a better and more cost effective choice for a smaller trailer. BTW.. I have used one for 5 years and it has been bouncing around in the camper as I take it off-road and etc... it will not hurt it. I would not be afraid of that in the least. Also, when mounted in a top cabinet by the roof as your picture shows... no different physics in the cooling than a roof mount. It all boils down to how big of a unit do you need to adequately cool. If 5,500 BTU will do it... then a roof mount 13,500 BTU is overkill and actually not going to do as well. I have seen some smaller roof top units ~8,000 BTU... but they still have some of the cons (all but the managing humidity part), are not much cheaper than the larger units... and are slightly too large for a small Honda Generator 2000ui.

flboy,
You are correct in your statements, IMHO. As a trained AC tech, de-humidification is the key, at least down south where I live (Georgia).
One of the window unit models I've been looking at is a 60000 btu Frigidaire AC. It pulls 1.3pints of moisture per hour and is right on par with the average 9000btu mini-split in terms of de-humidification removal, heck it pulls as much humidity as many small portable dehumidifers does. It pulls a whopping 5A in cool mode and has an EER rating of 11.1.
Most people have a tendency to oversize their AC causing it to short cycle, which simply means the AC unit satisfies its "sensible" load (tstat setting) before it satisfies its "latent" load(humidity) and then wonder why it feels wet and muggy in their living space. Most AC companies try keeping the humidity range in the 50-55% range during the summer time.

I like what several members have done and their creativity in cooling their trailers. Shadow Catchers solution intrigued me initially and got me to thinking. The pictures I posted earlier on were my attempt to help Chief design his AC solution as he and I are doing similar builds.
I myself have made a decision on which way I'm going with the AC on my build, now I need to start getting everything together.

Martin

[McDave]

Wow! Whodda thunk you could ruffle so many feathers with a simple factual statement about genuine, purpose built RV equipment? I didn't mean to aggravate that raw nerve with the Walmart crew. Amazing how many slide rules and credentials come flying out to justify how right they are and how wrong you are. Makes you wonder how Coleman has managed to stay in business all these years... just lucky I guess.
Listen Chief, I have a sense you possess all the intuitive skills you need to make cogent decisions about the equipment you want in your trailer. Let's face it, you don't ride Harley's because you have a budget problem, or because you care what your engineer neighbor with the MotoGuzzi dual sport thinks. You know what you want, be confident with your decisions and enjoy the years of trouble free service, starting with rev. 1.0... Put the A/C issue to bed on the first attempt and move on to conquer the other issues in a similar journeyman like manner.
Live to Ride, Ride to Live
McDave

[chiefairwrench]

Thanks for the encouragement will have pictures some time this week of how far we got this weekend. This weekend electrics and cabinet doors.

[m.colley]

Hey Chief,
Are you going to Thunder Beach rally in May?


Martin