Greg - you're welcome, of course.
The first thing I am wondering about is do you know what the compressor model is in the unit?
I do not, at this point. It has a part number of 0910870022. I tried Googling it but everything I came up with was MiniCool related - no OEM site or listing.
A long shot of a question, I am curious if it is a Danfoss or if it is one of them off brand high speed compressors coming out of Germany.
They do use a Danfoss compressor in at least one of their units - the units are produced in Spain, so I'd guess it is possible that it may be German as well.
Hmmm ... just scoped out Dirna's website - looks like they may just have come out with some new models:
Dirna S.A. Group
It's a little unclear but I'd guess that some of these models (on the left) are roofmount evap/cond/blower but using an engine driven compressor.
My sleeper and cab combined is 366 cubic feet in size (not precisely but close enough).
If it is indeed only 366 cu. ft. I'd think you would be in pretty good shape - particularly if it was well insulated.
I can see that the model you have may work OK or close to OK in high heat areas (Arizona, Texas)
It's amazing how cool 80 degrees can feel - when the humidity has been greatly reduced. I've sat in inside the truck when it was in the 90's outside with high humidity (Tulsa, a couple of weeks ago), but 80 inside the van - but with low relative humidity. Quite comfortable actually.
if there is a plan of attack with insulation in the sleeper and especially in the cab area, where about 60% of the heat seems to come from for the combination of the two.
Yeah - the insulation is critically important. Ray, at Espar of Michigan, was pretty impressed with what I had done on the insulation - to the point that he asked if it was ok for them to take pictures of it.
I know that one key is to keep the heat from rising through the floor of the sleeper, a lot of sleepers have zero insulation under the carpeting and metal and a lot of heat in the sleeper comes from the floor. I haven’t seen the latest model sleeper but two years ago there seemed to be no concern about the floor.
Any place there is exposed metal (connected to metal on the outside - especially that is in the sun - but any metal) you basically have a heatsink - with the heatsink radiating solar heat into the interior of the vehicle. Other materials will act as a heatsink too - but metal is especially good at it.
My insulation project was done in stages - I had insulation in the cavities on the ceiling - but the roof bows or supports were still exposed - it was incredible the amount of heat that they would radiate into the vehicle.
Heat will always flow to a cooler place to some degree ..... insulation just slows it down. Get enough of it and you for all practical purposes stop the flow.
In a cargo Sprinter (at least in my '06) there is flooring in the cargo area - it appears to be a sort of masonite/plywood composite - and there is some kind of insulation or batting underneath it - so that probably helps a great deal.
I am wondering what type of insulation you used in your Sprinter? Is it the standard bubble pack aluminized heat shield (which is not insulation) or a combination of that and some insulation (which I have here)?
I used a combination of four things - all readily available at Lowes (or probably Home Depot) - relatively cheaply (except for the Great Stuff - it's kinda pricey - luckily when I was doing this a local hardware chain had it on sale for like 1/2 price - so I cleaned out two of their stores
)
1. Dow 2" Blue Styrofoam Insulation on the walls and some of the door cavities (lower side door and upper rear doors)
2. Dow 1" Polyisocyanate Foam Insulation with a silver aluminumized coating on the roof (because I didn't want to lose any height in the cargo area and the 1" was slightly less than the depth of the roof bows) and on the upper cavity on the side door.
3. Great Stuff expanding foam insulation - this was used in a variety of places - on the walls and roof - mostly to fill in irregular cavities where I couldn't put the Dow foam in and to "lock" the Dow foam in place. I even used it on the back of the Dow foam as an adhesive - the stuff is really sticky - and once it's on something and hardens, it ain't going anywhere. In some instances I had to "hold" the solid foam in place mechanically for 24 hours while the expanding foam cured - but once it cured nothing was going anywhere. I also used it to just "cover" any metal that would radiate heat into the interior.
4. Silver aluminum "bubblewrap" radiant heat barrier - I covered the entire ceiling, walls (from the sidewall E-Track up), and the rear doors with this, using both 3M "77" (walls) and 3M "90" spray adhesive. (You need the higher strength "90" to get it to stay up on the ceiling - probably because of the intense heat coming through the roof. I tried the "77" on the ceiling - but it started coming loose after maybe 3 or 4 months, once it got warmer out) I covered everything with the silver bubblewrap - right over top the foam - as someone said "It's the Jiffy-Pop look".
I also used a caulking gun and Loctite foamboard adhesive, and construction adhesive, to secure the foam panels and the silver bubblewrap shield, respectively.
Do not use Owens Corning "pink" fiberglass insulation - besides the fact that it's probably unhealthy unless it's in a totally sealed cavity, it can (and will) retain moisture - which will reduce it's insulation value to nil.
I still want to pull the plastic door trim on the front doors and coat them with Great Stuff (just based on how cold they get in the winter) And I didn't get the silver bubblewrap on the lower sidewalls of the cargo area (already had the E-Track installed and it would have been too much hassle to pull it down)
Basically I need to go back thru and try and cover every remaining bit of exposed metal
with something.
The last thing is that I am trying to avoid the full fledge APU and actually thought about using a combination of some solar and a small slow speed engine (which I have) to recharge the system. I have 16 sq feet of surface area on the cab alone not to mention (don’t laugh) 106 sq feet on the box for solar panels…. So… you can see where I am going with this.
Yeah - that's one thing I haven't checked into - but it's a possibility I suppose, especially given the advances in solar panel technology. Whether it would be cost effective or not I have no idea.
On a sprinter, there is a large surface area that a panel can go on, maybe the added weight can be justified when it comes to replacing some of the amperage while sitting in the sun.
Perhaps - but I've got quite a bit up there already - AC unit, roof fan/vent, CB antenna, and my Qualcomm - but it's certainly worth checking into.