Rev's Ride 1
- Thread starter dhalltoyo
- Start date
RLENT
Veteran Expediter
Batteries
Well ..... I been busy
..... sorry for the delay.
The AC unit runs from four Group 29 Walmart Everstart Maxx "deep cycle" batteries, rated at 125 amp hour capacity each. The battery bank's total capacity is 500 amp hours, maximum usable capacity is really 250 amp hours (because discharging below 50% capacity shortens battery life)
The batteries cost around $75 or $85 each, depending on whether you have a old one (core) to turn in for each one you buy - so figure around $375 or so for a cost for the batteries alone.
They carry a 36 month warranty with 18 month free replacement. These batteries are not a "true" deep cycle battery - they are a hybrid deep cycle/starting battery as I understand it - but they are relatively cheap - and if you kill them before 18 months you can get them replaced for free, or at a somewhat reduced cost if they fail before 36 months.
I am using them with a Xantrex battery monitor so I can see the state of charge and avoid drawing them down below 50% - so how long they last remains to be seen - hopefully they will last a good long time (I'd be happy with 3 years and tickled pink with 5 years.) If they don't, or if I find at some point I'd really rather have something with more juice, I may replace them with something else (6v golf cart batteries, high-end AGM's, etc.)
Well ..... I been busy
..... sorry for the delay.The AC unit runs from four Group 29 Walmart Everstart Maxx "deep cycle" batteries, rated at 125 amp hour capacity each. The battery bank's total capacity is 500 amp hours, maximum usable capacity is really 250 amp hours (because discharging below 50% capacity shortens battery life)
The batteries cost around $75 or $85 each, depending on whether you have a old one (core) to turn in for each one you buy - so figure around $375 or so for a cost for the batteries alone.
They carry a 36 month warranty with 18 month free replacement. These batteries are not a "true" deep cycle battery - they are a hybrid deep cycle/starting battery as I understand it - but they are relatively cheap - and if you kill them before 18 months you can get them replaced for free, or at a somewhat reduced cost if they fail before 36 months.
I am using them with a Xantrex battery monitor so I can see the state of charge and avoid drawing them down below 50% - so how long they last remains to be seen - hopefully they will last a good long time (I'd be happy with 3 years and tickled pink with 5 years.) If they don't, or if I find at some point I'd really rather have something with more juice, I may replace them with something else (6v golf cart batteries, high-end AGM's, etc.)
RLENT
Veteran Expediter
How long ?
As far as how long it can run before recharging is necessary, I have run the unit overnight for at least a 10 hour or so stretch and when I woke up my battery monitor showed the battery bank still had a capacity of 76%. That was in West Memphis last week and was the instance I referred to previously. I have seen the battery bank's capacity as low as 60-some percent (10% remaining) - although I'm unsure exactly how long it was run on that occasion - or whether the bank was fully charged to 100% when I started it ... wasn't paying that close attention at the time. Thus far I have never run the battery bank down to 50% capacity when using the AC unit overnight (or more accurately, while I was sleeping.) That was also without running the inverter, refrigerator/freezer, or microwave. (My inverter died a couple of weeks ago and I am waiting on a replacement.)
In actual practice, the answer to the question of "how long can it run ?" can be somewhat variable - it will never be a hard and fast number - because it depends on how much cooling the unit has to provide, which varies according to the current conditions you are in. Cooling off a well-insulated enclosed area at night, when the temps are in the 80's say, is very different than trying to cool the same volume (but uninsulated) when the temperature hits the mid to high 90's (or more) ..... and the sun is beating down on you.
The AC unit's power draw varies - depending on how hard it is running and how much it is cooling. I really need to spend a little more time observing and recording the actual amp draws under various conditions. The power draw varies according to how many compressors are running (it has two - and you can select one or both) and how fast the blower fan is running (it has 5 speeds - from very low to a really serious "I think that might a tornado back there" level) - but generally the amp draw ranges from from under 5 amps to around 35 amps or so.
When the unit starts up it is in the "automatic" F4 mode (described on the website) ..... where the compressors and fan speeds run according to the cooling need - it will automatically cycle up and down as it needs to provide more or less cooling. When it does this, I know it is varying the fan speed (clearly observable) and I would assume that the compressors vary as well too (based on an obserable variation in the amperage draw.) You can also set the fan speed manually if you desire more airflow, and/or turn off one of the compressors to reduce the power draw.
As far as how long it can run before recharging is necessary, I have run the unit overnight for at least a 10 hour or so stretch and when I woke up my battery monitor showed the battery bank still had a capacity of 76%. That was in West Memphis last week and was the instance I referred to previously. I have seen the battery bank's capacity as low as 60-some percent (10% remaining) - although I'm unsure exactly how long it was run on that occasion - or whether the bank was fully charged to 100% when I started it ... wasn't paying that close attention at the time. Thus far I have never run the battery bank down to 50% capacity when using the AC unit overnight (or more accurately, while I was sleeping.) That was also without running the inverter, refrigerator/freezer, or microwave. (My inverter died a couple of weeks ago and I am waiting on a replacement.)
In actual practice, the answer to the question of "how long can it run ?" can be somewhat variable - it will never be a hard and fast number - because it depends on how much cooling the unit has to provide, which varies according to the current conditions you are in. Cooling off a well-insulated enclosed area at night, when the temps are in the 80's say, is very different than trying to cool the same volume (but uninsulated) when the temperature hits the mid to high 90's (or more) ..... and the sun is beating down on you.
The AC unit's power draw varies - depending on how hard it is running and how much it is cooling. I really need to spend a little more time observing and recording the actual amp draws under various conditions. The power draw varies according to how many compressors are running (it has two - and you can select one or both) and how fast the blower fan is running (it has 5 speeds - from very low to a really serious "I think that might a tornado back there" level) - but generally the amp draw ranges from from under 5 amps to around 35 amps or so.
When the unit starts up it is in the "automatic" F4 mode (described on the website) ..... where the compressors and fan speeds run according to the cooling need - it will automatically cycle up and down as it needs to provide more or less cooling. When it does this, I know it is varying the fan speed (clearly observable) and I would assume that the compressors vary as well too (based on an obserable variation in the amperage draw.) You can also set the fan speed manually if you desire more airflow, and/or turn off one of the compressors to reduce the power draw.
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Re: Batteries
Can that Xantrex monitor be set to shut things down at the 50% point? Total weight of the 4 batteries, monitor and a/c system is maybe 300 pounds? I'd run my inverter etc. off the existing setup and only use this for cooling to maximize run time. I'm just debating if it would save enough APU hours to be worthwhile. Can that a/c unit be plugged into a shore power also?
Can that Xantrex monitor be set to shut things down at the 50% point? Total weight of the 4 batteries, monitor and a/c system is maybe 300 pounds? I'd run my inverter etc. off the existing setup and only use this for cooling to maximize run time. I'm just debating if it would save enough APU hours to be worthwhile. Can that a/c unit be plugged into a shore power also?
RLENT
Veteran Expediter
How large an area is it cooling ?
Initially, after I had the unit installed, it was cooling the entire area inside my Sprinter (the Sprinter's cargo capacity is listed as 473 cu. ft. - so I'd guess the actual volume of the entire inside is around 800 cu. ft. at least - perhaps more) .... well, I really should say "trying to cool" the entire inside of my Sprinter.
In spite of the fact that my Sprinter is very well insulated for the most part (I actually haven't finished it- and I'm sure having done it once, I'm sure I could do a much better job the second time around) the unit could not keep up with the amount of heat gain produced by such a large surface area - particularly on hot day when the sun was out. The MiniCool is only a 4760 BTU unit and I suppose it would be silly to think that it would - although I may have some additional info regarding this ..... hopefully after tomorrow. (I understand the stock Sprinter AC unit is 15K BTU's - although I haven't been able to verify that - if that is actually true, it should tell you something)
Since then I have stuck up a temporary curtain using some cheap felt-like material I got at Walmart just behind my bunk to section off the front from the rear cargo area, as I was out on the road. It doesn't even really seal it off all that well - it's just hanging there - but it made an immediate difference - and I plan come up with a little better solution that will really seal the front living area off.
It is a workable solution to provide a comfortable sleeping environment for me - possibly due to the fact that I have the unit placed directly over my bunk and the cool air blows directly down on me. I had no illusions that the unit would cool the entire truck on a hot day while it's sitting out in the hot sun. But again, I may have some revised data to report on that after tomorrow
Initially, after I had the unit installed, it was cooling the entire area inside my Sprinter (the Sprinter's cargo capacity is listed as 473 cu. ft. - so I'd guess the actual volume of the entire inside is around 800 cu. ft. at least - perhaps more) .... well, I really should say "trying to cool" the entire inside of my Sprinter.
In spite of the fact that my Sprinter is very well insulated for the most part (I actually haven't finished it- and I'm sure having done it once, I'm sure I could do a much better job the second time around) the unit could not keep up with the amount of heat gain produced by such a large surface area - particularly on hot day when the sun was out. The MiniCool is only a 4760 BTU unit and I suppose it would be silly to think that it would - although I may have some additional info regarding this ..... hopefully after tomorrow. (I understand the stock Sprinter AC unit is 15K BTU's - although I haven't been able to verify that - if that is actually true, it should tell you something)
Since then I have stuck up a temporary curtain using some cheap felt-like material I got at Walmart just behind my bunk to section off the front from the rear cargo area, as I was out on the road. It doesn't even really seal it off all that well - it's just hanging there - but it made an immediate difference - and I plan come up with a little better solution that will really seal the front living area off.
It is a workable solution to provide a comfortable sleeping environment for me - possibly due to the fact that I have the unit placed directly over my bunk and the cool air blows directly down on me. I had no illusions that the unit would cool the entire truck on a hot day while it's sitting out in the hot sun. But again, I may have some revised data to report on that after tomorrow
RLENT
Veteran Expediter
Re: Batteries
Well, yes - it actually could:
The Xantrex has a set of contacts to drive a relay to drive an (audible or visual) "alarm" - I'd think it would be relatively easy to wire it to drive sometype of switch or solenoid that would just shut off the power. The "low" (relay on or driven) and "high" (relay off) points can set individually to any value you desire (% of battery bank capacity)
You're too quick for me Leo
Well, yes - it actually could:
The Xantrex has a set of contacts to drive a relay to drive an (audible or visual) "alarm" - I'd think it would be relatively easy to wire it to drive sometype of switch or solenoid that would just shut off the power. The "low" (relay on or driven) and "high" (relay off) points can set individually to any value you desire (% of battery bank capacity)
The weight of the AC Unit itself is 66 lbs. I'd guess the batteries are 50 to 65 lbs apiece, although I've not weighed them alone.
Probably a smart way to go. I'm considering not using my refrigerator/freezer during the summer months to avoid the reduction of run times that result from the constant power draw, and using the microwave only when the engine is running.
Yeah ... dunno the economics on that .... since I don't have an APU.
From the factory, no. But I'd bet that you could find some sort of a voltage converter that would take 120v AC and turn it into 12v DC - as long as it could handle about a 40A or 50A 12v DC load, you'd be golden.
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RLENT
Veteran Expediter
Sensible addition to a D unit ?
In answer to whether it would be a sensible solution to a D unit, that probably again depends on a number of factors - including what your expectations are. But, in this day and age of high fuel costs, I would think that that either a Dirna MiniCool or a DC Airco unit could be a sensible cost-effective addition. Here's how I looked at it for myself:
Sprinter consumes approximately 1/3 of a gallon per hour idling. Assume fuel costs $4.50 per gallon. Assume that you can eliminate 12 hours per day of idling to cool the vehicle (remember - I don't particularly care for excessive heat or high humidity - and, in combination, they just ain't my bag) Assume in-service (meaning living in the vehicle) for 3 weeks per month with the remaining time off at home. Assume a 5 month cooling season (mid May to mid September) Remember it doesn't have to be real hot outside to need cooling (at least for me) - it just has to be warm and the sun has to be out - heat gain inside the vehicle will do the rest.
12 (hours) x 1/3 (of a gallon) = 4 gallons per day. 4 (gallons) x $4.50 = $18 per day (cost to idle)
$18 (per day) x 21 days x 5 month cooling season = $1890 in fuel savings.
Figure a service life of 5 years for the truck and the AC unit (wild guess): $1890 x 5 = $9450 in reduction in fuel costs (at today's prices .... well, yesterday's actually ....)
I consider the above to be conservative figures for me. Of course, fuel is currently higher in many places (national average) And I gotta think that it still might be warm down south even in April or October - so 5 months usage could be a little short (but on the flip, you might not have to run the truck every day to cool it either) And the reality is that I'll probably end up staying inservice more than given above over the next four months. Using the current national average fuel cost, assuming a month longer cooling season, and an in-service/availability of 90%, the cost savings would be more on the order of $3078 per year. At that point the high initial outlay for the unit starts to seem not quite so bad. And it doesn't take into account any reduced maintenance cost as result of not idling as much.
If you are idling the truck to keep cool, the question might become "Can you afford not to (go with some type of solution to avoid idling ?)
Obviously a big truck uses more fuel idling than a Sprinter does, so the return would be alot quicker.
The DC Airco 9000 offers greater cooling capacity (9K BTU) but at the cost of higher power consumption (probably about double) The Dirna is less power hungry - but also provides less cooling (about half of the DC Airco 9000) I think the units are around the same cost, but I'm not positive on that. I was actually (very pleasantly) surprised at how little power the MiniCool consumes.
The beauty of any 12v AC system is that they use a power source that is replenished (at no real additional cost) when you drive down the road. Of course, you do need a decent sized alternator to recharge the batteries in a reasonable time.
My Sprinter has a 150 amp alternator, when idling it will fully recharge the batteries in around 6 to 10 hours or so, depending on how low they were. Running down the road it's faster - maybe 6 hours - because the alternator output is higher than it is at idle.
And in either scenario the batteries will regain most of the capacity (90%) relatively quickly - in a few hours (2 to 4) - it's stuffing the last 10% or so in that is slower, and takes more time. And the battery doesn't have to be fully recharged every time in order to use it - if it's only 90% when you shut the truck off no big deal.
In answer to whether it would be a sensible solution to a D unit, that probably again depends on a number of factors - including what your expectations are. But, in this day and age of high fuel costs, I would think that that either a Dirna MiniCool or a DC Airco unit could be a sensible cost-effective addition. Here's how I looked at it for myself:
Sprinter consumes approximately 1/3 of a gallon per hour idling. Assume fuel costs $4.50 per gallon. Assume that you can eliminate 12 hours per day of idling to cool the vehicle (remember - I don't particularly care for excessive heat or high humidity - and, in combination, they just ain't my bag) Assume in-service (meaning living in the vehicle) for 3 weeks per month with the remaining time off at home. Assume a 5 month cooling season (mid May to mid September) Remember it doesn't have to be real hot outside to need cooling (at least for me) - it just has to be warm and the sun has to be out - heat gain inside the vehicle will do the rest.
12 (hours) x 1/3 (of a gallon) = 4 gallons per day. 4 (gallons) x $4.50 = $18 per day (cost to idle)
$18 (per day) x 21 days x 5 month cooling season = $1890 in fuel savings.
Figure a service life of 5 years for the truck and the AC unit (wild guess): $1890 x 5 = $9450 in reduction in fuel costs (at today's prices .... well, yesterday's actually ....)
I consider the above to be conservative figures for me. Of course, fuel is currently higher in many places (national average) And I gotta think that it still might be warm down south even in April or October - so 5 months usage could be a little short (but on the flip, you might not have to run the truck every day to cool it either) And the reality is that I'll probably end up staying inservice more than given above over the next four months. Using the current national average fuel cost, assuming a month longer cooling season, and an in-service/availability of 90%, the cost savings would be more on the order of $3078 per year. At that point the high initial outlay for the unit starts to seem not quite so bad. And it doesn't take into account any reduced maintenance cost as result of not idling as much.
If you are idling the truck to keep cool, the question might become "Can you afford not to (go with some type of solution to avoid idling ?)
Obviously a big truck uses more fuel idling than a Sprinter does, so the return would be alot quicker.
The DC Airco 9000 offers greater cooling capacity (9K BTU) but at the cost of higher power consumption (probably about double) The Dirna is less power hungry - but also provides less cooling (about half of the DC Airco 9000) I think the units are around the same cost, but I'm not positive on that. I was actually (very pleasantly) surprised at how little power the MiniCool consumes.
The beauty of any 12v AC system is that they use a power source that is replenished (at no real additional cost) when you drive down the road. Of course, you do need a decent sized alternator to recharge the batteries in a reasonable time.
My Sprinter has a 150 amp alternator, when idling it will fully recharge the batteries in around 6 to 10 hours or so, depending on how low they were. Running down the road it's faster - maybe 6 hours - because the alternator output is higher than it is at idle.
And in either scenario the batteries will regain most of the capacity (90%) relatively quickly - in a few hours (2 to 4) - it's stuffing the last 10% or so in that is slower, and takes more time. And the battery doesn't have to be fully recharged every time in order to use it - if it's only 90% when you shut the truck off no big deal.
Re: Sensible addition to a D unit ?
My Rigmaster uses about 1/3 gal per hour to run the a/c so your numbers for idling would be very similar to substituting for an APU. I'm sure someone who knows what they're doing could wire it so these batteries would be charged by the truck when driving and by the APU when sitting.
My Rigmaster uses about 1/3 gal per hour to run the a/c so your numbers for idling would be very similar to substituting for an APU. I'm sure someone who knows what they're doing could wire it so these batteries would be charged by the truck when driving and by the APU when sitting.
RLENT
Veteran Expediter
Re: Sensible addition to a D unit ?
Blue Sea Systems Battery Switches
I used one them as the "main disconnect" switch to disconnect the bank from all loads.
Plus ya save on the maintenance, due to the reduction of hours of use of the APU.
There's probably even an "automatic" solution out there someplace. And if not, it would be relatively easy to do manually, with a Marine A/B/A+B battery switch:
Blue Sea Systems Battery Switches
I used one them as the "main disconnect" switch to disconnect the bank from all loads.
greg334
Veteran Expediter
Rlent,
Thanks for all that.
The first thing I am wondering about is do you know what the compressor model is in the unit?
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.
My sleeper and cab combined is 366 cubic feet in size (not precisely but close enough). I can see that the model you have may work OK or close to OK in high heat areas (Arizona, Texas), 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.
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.
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)?
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. 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.
Thanks for all that.
The first thing I am wondering about is do you know what the compressor model is in the unit?
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.
My sleeper and cab combined is 366 cubic feet in size (not precisely but close enough). I can see that the model you have may work OK or close to OK in high heat areas (Arizona, Texas), 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.
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.
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)?
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. 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.
RLENT
Veteran Expediter
Greg - you're welcome, of course.
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 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.
)
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.
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.
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.
If it is indeed only 366 cu. ft. I'd think you would be in pretty good shape - particularly if it was well insulated.
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.
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.
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 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.
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.
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.
RLENT
Veteran Expediter
Greg,
The compressors in the Mini-Cool are a pair of Danfoss units.
A couple of other things:
You asked about solar panels - I believe they (Espar of Michigan) are actually looking into and researching this currently.
Leo, you asked about whether running the unit off of shore power was possible - while what I said was true (the Mini-Cool unit doesn't have a stock or factory connection for shore power) from talking to one of the guys yesterday, I believe they may have (or are working on) a solution for this, using an inverter/charger.
And by the way (Leo), exactly how big is your sleeper ? (length)
The compressors in the Mini-Cool are a pair of Danfoss units.
A couple of other things:
You asked about solar panels - I believe they (Espar of Michigan) are actually looking into and researching this currently.
Leo, you asked about whether running the unit off of shore power was possible - while what I said was true (the Mini-Cool unit doesn't have a stock or factory connection for shore power) from talking to one of the guys yesterday, I believe they may have (or are working on) a solution for this, using an inverter/charger.
And by the way (Leo), exactly how big is your sleeper ? (length)
My sleeper is 90" front to back and somewhere around 94" side to side and around 86" high. A good bit of that is taken up by cabinets, dinette seats etc. though so the actual volume of airspace is much smaller than those dimensions would yield. My wild supposition would be about 50-60% in actual airspace.
RLENT
Veteran Expediter
One additional thing - (one of ?) the other line(s) of 12v DC AC units that Ray is handling currently are from DC Power Solutions - these are even more powerful than the DC Airco units. The DC Power Solutions TopCool unit (roof mount) provides up to 11K Btu's of cooling capacity:
DC Power Solutions
They also make a split system for mounting on the back of a semi-tractor.
These units are produced in the US. I do not know the cost on them (forgot to ask)
DC Power Solutions
They also make a split system for mounting on the back of a semi-tractor.
These units are produced in the US. I do not know the cost on them (forgot to ask)
RLENT
Veteran Expediter
Ok, so that's approximately 420 cu. ft.
The area that I'm cooling in my Sprinter is roughly 8' long x 5.5' wide x 6' tall - or about 264 cu ft. Some of it is taken up by my bunk, refrig/freezer, microwave, and other crap (seats, desk, etc.) So it is considerably smaller.
One factor that one realistically has to consider when sizing a cooling system is sources of additional heating load (beyond just the ambient outside temperature and the sun) and what effect these will have on the performance of a cooling system. Anything you can do to minimize such factors will increase the performance and extend your run times, simply because the system isn't having to work as hard. And it may be the difference between achieving an acceptable result and an unacceptable one.
My guess is that you would probably need to go with the larger unit to cool that large of an area - but you should really consult with Ray on it - he won't steer you wrong. I'd assume that you have a refrigerator/freezer and would want to use it during the summer months (remember a refrigerator/freezer works by removing heat from an enclosed space and exhausting it somewhere - probably into the space you are trying to cool.)
I'm probably going to forego the use of my refrig/freezer during the summer months - to avoid the power draw on my battery bank so I can increase the run time for the AC unit and to avoid adding additional heat load into the space i'm trying to cool. Since I'm in a van, it's not a big deal for me to whip into a grocery store and grab a frozen meal and 'nuke it in the microwave. I'll only run the big inverter (more heat load) when I need to use the microwave. I'm totally willing to make that tradeoff in convenience to order to stay comfortably cool - besides I generally only eat one meal per day anyways. I have a small (400w) inverter I can use as needed to charge my laptop and run the scanner)
I also have some reflective window covers I put up on the windshield and side windows. On a sunny day these are critical to reducing solar heat gain.
The area that I'm cooling in my Sprinter is roughly 8' long x 5.5' wide x 6' tall - or about 264 cu ft. Some of it is taken up by my bunk, refrig/freezer, microwave, and other crap (seats, desk, etc.) So it is considerably smaller.
One factor that one realistically has to consider when sizing a cooling system is sources of additional heating load (beyond just the ambient outside temperature and the sun) and what effect these will have on the performance of a cooling system. Anything you can do to minimize such factors will increase the performance and extend your run times, simply because the system isn't having to work as hard. And it may be the difference between achieving an acceptable result and an unacceptable one.
My guess is that you would probably need to go with the larger unit to cool that large of an area - but you should really consult with Ray on it - he won't steer you wrong. I'd assume that you have a refrigerator/freezer and would want to use it during the summer months (remember a refrigerator/freezer works by removing heat from an enclosed space and exhausting it somewhere - probably into the space you are trying to cool.
)I'm probably going to forego the use of my refrig/freezer during the summer months - to avoid the power draw on my battery bank so I can increase the run time for the AC unit and to avoid adding additional heat load into the space i'm trying to cool. Since I'm in a van, it's not a big deal for me to whip into a grocery store and grab a frozen meal and 'nuke it in the microwave. I'll only run the big inverter (more heat load) when I need to use the microwave. I'm totally willing to make that tradeoff in convenience to order to stay comfortably cool - besides I generally only eat one meal per day anyways. I have a small (400w) inverter I can use as needed to charge my laptop and run the scanner)
I also have some reflective window covers I put up on the windshield and side windows. On a sunny day these are critical to reducing solar heat gain.
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The gross area is 420 but when you take out the cabinets, dinette storage, etc. there's probably no more than about 250 cubic feet exposed to the air so it would be similar to the area you are cooling. The windows have insulated covers over them. There's fairly decent insulation in the rest of it as well, so the one you have might be adequate.
Jack_Berry
Moderator Emeritus
is that right? 400 w? maybe that is why you are your 22nd invertor this year. (can't insert smiley here. for some reason i can only get smileys in the title line). bump that up a bit maybe. might not be big enough.
RLENT
Veteran Expediter
Jack,
.... 22nd ... cute .....
That inverter is a small Cobra I bought at the J after I had been out just a week or so, just to charge up the laptop - I was really still in the process of deciding which inverter I was gonna go with as the main inverter.
The one that blew up was an AIMS 2000w (5000w peak) pure sign wave unit
.... 22nd ... cute .....
That inverter is a small Cobra I bought at the J after I had been out just a week or so, just to charge up the laptop - I was really still in the process of deciding which inverter I was gonna go with as the main inverter.
The one that blew up was an AIMS 2000w (5000w peak) pure sign wave unit
RLENT
Veteran Expediter
Leo,
Yeah .... maybe ...... best to talk to Ray. Couple of things:
What color is the truck/sleeper ? ... darker colors could mean more heat gain/load (.... ask Jack about his blue van)
Assume you can curtain off the sleeper from the cab ?
Do you plan to use the unit during the day and be up and doing stuff ? Or just when sleeping ? The human body produces less heat when resting and it's easier to keep cool (a human body can give off as much heat as a 100w light bulb or around 340 or Btu's/hour)
Yeah .... maybe ...... best to talk to Ray. Couple of things:
What color is the truck/sleeper ? ... darker colors could mean more heat gain/load (.... ask Jack about his blue van
)Assume you can curtain off the sleeper from the cab ?
Do you plan to use the unit during the day and be up and doing stuff ? Or just when sleeping ? The human body produces less heat when resting and it's easier to keep cool (a human body can give off as much heat as a 100w light bulb or around 340 or Btu's/hour)