Lets talk AC again

[bapos]

I still don't see how people cant operate with out a generator? I mean I know for the short trips home from your purchase and what not but this is a deal that there is no way I can see in the future of any bus I have with out a generator of some type? I guess I like too many comforts and being very cool when I travel in a tin can?

The LP deal was the main reason why I got that type of generator. I have enough issues with small engine on lawn equipment with carb issues now that it would totally piss me off to have a expensive unit and it not fire up when I needed it to. 2nd... I guess Im a power freak. Im worried my 7k wont be enough even though the amount of electrical devices I will have on board really are not going to be that much. Another one of those over build versus under build. I would seriously like a 10k RV unit out of a coach bus

[lornaschinske]

Originally Posted by bapos

I still don't see how people cant operate with out a generator? I mean I know for the short trips home from your purchase and what not but this is a deal that there is no way I can see in the future of any bus I have with out a generator of some type? I guess I like too many comforts and being very cool when I travel in a tin can?

These are the same people who won't move an inch in their cars without the AC on!

We will NEED a generator for going down the road. We will need to power a 12 cf freezer full of food, a 4 cf refrigerator full of beverages (water and soda), another 4 cf refrigerator full of food and in summertime, the air conditioner (in the front... maybe the rear). Once stopped, since we are cheapskates and the less we eat out the more $$ we have to spend elsewhere, I will need to run the microwave, heat water for a bath and clean up. Run the AC in the heat, watch a bit of TV before turning in for the night (after checking for SKP psyopaths parked too close even though they were warned). If we wanted to live in a metal tent without any amenities, then we would not have spent the time and money converting the bus. David & I feel that we have spent enough years in tents.

[Das Mel]

Originally Posted by bapos

I still don't see how people cant operate with out a generator?

Because sometimes you run into total dipwad freaks like me who doesn't like to run AC, even in 104 degree heat (my car has it, yes, but I never turned it on during the ride out West. I figure if Mum and Dad was suffering without it then I would, too). I run the roof air for the fan when it's muggy out, but that's about it. I figure I can sit in a diner with a glass of tea and wi-fi if I want to cool off.

Will certainly have to either empty the fridge and freezer before I make another cross-country move, or figure out just what is wrong with the Onan (the crappy one Mum's talking about) and get it fixed so I can run power to the silly blighters. Or just eat jerky and fruit while under way and keep the cooler filled with ice. Actually, I might do that anyway.

[bansil]

I know 90 * with 65% humidity isn't hot for some of you

We still have windows and roof vents and with them open(strategically) we roll down the backrads at 45mph using a small 1000 watt invertor and power the fridge/freezer, laptop and 2 24" box fans.

I will end up running ac on road tho'!!

I have been thinking of studying up on capacitors to help kickstart the front window ac unit(it will run on the invertor,just has an issue kicking on compressor sometimes)

[bapos]

I totally respect those who can "ruff it" with out adding ac. Most of the thoughts in my head are just for comfort of the people inside of the bus. I haven't really got in to the idea of refrigerators/freezers for longer term food storage. I think the smaller DC power needs can be fit by house batteries and those can be fed by either alternator or recharged when plugged in at your destination. I am not far along in this to think about longer trips in a bus. Mine are 100 mile type get aways like football games, festivals, etc.

I am going to take some heat gun temp measurements on the bus since I am in preinsulation stage and in a nice good n hot part of the summer for Texas and hopefully have something to compare to so hopefully the 100 dollars I spent on polyiso will be money well spent.

[lornaschinske]

Bansil, they make a soft start capacitor for rooftop ac units. You may be able to use that.

Bapos, the interstate was 10° to 25° hotter than ambient temps when we made our run thru TX on I-20. The road got hotter and the day wore on. It was this time of year too.

I feel that just because we have air conditioning, we don't have to run it. Right now I don't have the front air turned on as it's comfortable. We sleep with the rear air on because it helps our allergies. A curtain seems to keep most of the cool air in the back section of the bus. Soon I will have to start up the front air. Having the bus closed up has really helped with the fine dirt that we were living in. We have a dust storm daily in our current location.

BTW, I paid the site rent yesterday. With 6,400 btu plus 5050 btu airs running, we did not exceed our electric allotment. That's good. Because when we move to TX (Sept2015) we will pick up a lot zoned to allow us to park the bus on(acutually two buses), build an "RV pad" and will be paying for our own utilities (electric, water, sewer, DISH not cable and internet via DISH). We need to keep our electric use low.

[bapos]

Bansil..... Not sure if you have seen them but if you look at a AC supply house they have hard start kits premade so all you have to do is plug them in to some of the existing wiring and they will help with the power shortage at times. You seem like a well versed guy you probably could build one your self.

lornaschinske.... yeah Im worried about that. My bus on the drive home from its purchase I could not believe how much heat came off the dog house from that drive home. It was in May so satans grip hadn't got a hold of us yet so I need to come up with some way to block that out. I was maybe thinking some Lizard skin or something along those lines. Only bad thing is Im sure its very greasy and touch to reach to spray but any ideas would be good if people can share. Pulling the motor and trans is not on my list to do unless we have a major failure?

I guess a question to ask those on here to try and get the AC talk back to going. I have one AC unit in the bus currently. Said it works but It looks as ruff as a corn cob and well Im sure there are better units out there. It will work for now but Ill be changing it out with a 15k btu unit.Its probably 1/3 from the front of the bus. There is a vent pop up in the back I am thinking about removing and putting the 2nd unit there? Does any one have any ideas as to an ideal placement? I just have a feeling with my dog house heat issue and the over all size of the bus that the front of it will be hotter than the later half. I will probably be the one to drive it most of the time and would like to be comfortable. I would think fans circulating would help but would like input from those would have already done it and maybe have some ideas of "if I had to do it all over again I would....."

I know with home construction air infiltration is a HUGE issue. Not just from a cooling stand point but also from dust and allergens. Seal it up as best you can. They say the devil is in the details... well that's a big detail.

[Hvbuzz]

If your AC is 1/3 from the front right now I would go with it there. My 15,000btu is about halfway on about the same size bus as yours. I could have gone alittle more forward, and it probably would have helped. The back stays cool. I also have a pretty straight run for the air to move forward or back. I knew going in, that the cool air needed a straight shot to front or back. It was a guessing game. I really didn't want two AC's because I knew I didn't want to power two. Run what you have now, and then if you buy a second bigger one, I would put that one up front, and your move your older one to the back.

[bansil]

When not sleeping,I have bedroom door open, with a 24inch (.94 amp) box fan blowing at feet level forward.

This seems to really help the tw ac's worksince I am circulating cool air down low so it mixes with warm air and the ac's can pic it up.

My biggest issue right now is the thermal bridge from the roof bows...a deck type cover will help over 100% with transfered heat,once I put "shade" and air space over them

[bapos]

Here is a good look at the side profile of my bus



As you can see its about a 1/3 of the way. I have decided Im going to insulate the roof and sides even if it takes longer and costs more. Since I am not going to have a lot of windows and plan on seriously sealing it up I think the pay off will be more worth it and if I decide to sell the bus it would be a good selling point to attract a buyer.

I may go take a extension cord out there and see if that unit works. The previous owner said it did so I guess it can remove all doubt?


I think the fans blowing are a good idea to cool it down. I know in home HVAC design we use some calculations as to what size register to use to make sure you paint the wall you need to cover so that the air is moved through out the room.

I am also curious as to how much a deck would help with that heat issue? I don't want to go full but some coverage has to help let alone the ability to store stuff up top would be a good thing.

[bapos]

I am still in debate over seeing if a mini split system will work in a bus? Here is a video I found of a guy putting one in a small travel trailer. What do you think?

http://www.youtube.com/watch?v=IHDT5ZEpKkw

[lapeer20m]

my alternator stopped charging while i was in Nevada. I ran an EU2000 on the roof of my skoolie for 2,000 miles running a battery charger and a freezer on my way back to michigan. The generator ran fine with no issues.

I used the same generator to run a small window ac unit when the power was out. I was surprised that the compressor on this particular unit did not kick on until several minutes after the ac unit was running. I can understand how a person could plug a couple units in and think the generator was running them just fine, only to find out later that the compressors had not started up yet.

I think that if i do another skoolie i will install an engine driven a/c compressor to make cold air while driving. 4 times i drove through the desert to burningman and back in a black bus without a/c. I think all the parts could be scavenged from a suburban or other large SUV from a junk yard. There is very little magic in a AC system. Basically there is a compressor, a hot radiator, and a cold radiator. The most difficult part of the project is finding a V belt pulley to put on a compressor designed for a serpentine belt.

Something you can do to make your ac much more efficient (ie: make more cold air with less energy) is to replace the refrigerant with R290. R290 is nearly free, it's also known as propane. It is a much better refrigerant than R134a or most of the alternates. I've had excellent success using propane as a refrigerant in various applications. It is also much less likely to leak as the molecules are larger than R134a, it's non-ozone depleting (if you believe in that ozone hooplah) and you use only 30% as much propane as you would R134a.

[ol trunt]

Mr. Moderator, while I agree with all you have said in your last post re propane, you have left out the most important part. Propane can safely only be used in a cooling device which has been designed and tested for its use. Anyone who contemplates using propane as a refrigerant needs to do a through study of his plan. Failure to do this could result in-- BOOM!!! Might anyway. Just saying......

[Accordion]

I must admit that I have never heard of propane being used as a refrigerant.

I do know that ammonia is used in the RV type refrigerators.

[Bullwhacker007]

There is allot controversy regarding "R290" ie propane.
You have to use a filtered type due to a "tar" like residue in motor rated propane.
I am not saying use I am just mentioning what I did experimenting with it.
The comment about it having to be used in a system specifically designed for its use isn't really correct.
The "orifice" tube in the automotive AC is used to control the refrigerant flow through the system and kind of a filter as well.
The issue is allot of people comment about exploding if you use it. There is far more risk in a "explosion" in an accident with that great big fuel tank on your vehicle.
The other thing is 134a degenerates when exposed to high heat into phosphine gas - orderless and deadly. Ice labs when you see news of all the dead bodies found at one and you see the guys wearing "spacesuits" is because of that gas...
Heck there are case of this poisoning at Vet Hospitals due to a pet ingesting Zinc Phosphate. Used in pest poison. Contact with the stomach acid, etc. and it creates phosphine gas..
http://www.cdc.gov/mmwr/preview/mmwrhtml/mm6116a3.htm

Back on the subject.
I've charge automotive systems with "propane" as a test refrigerant used to look for leaks.
Given that a new 30lb jug of 134a now is costing me 300.00; that is very expensive to use looking for leaks. The propane "test" gas costs about 10-20 cents..
I fix the leak; pull a vacuum and retest; no leaks then pull a vacuum again and then and only then recharge with the 134a..
Also R290 "propane" is very ozone friendly and allot more environmentally safe.
You don't have to construct a 100 million dollar plant to manufacture 13a and DuPont is the only one who hold the patent to it...
Also propane is actually used in many countries beside USA for this very use; automotive, etc.
Remember if you get that great AC repair done in Tijuana Mexico; the odds are the gas is propane...

[ol trunt]

Ya pays ya money and ya takes ya chances. Propane is cheap so I wonder why the major auto manufacturers haven't gone that way?

[ol trunt]

Bullwhacker007. Interesting article on rat poison and phosphine. I just looked up the MSDS sheet on R 134a (National Refrigerants Safety Data Sheet, 12/20/2012) and they do not list phosphine as thermal decomposition product of R 134a. Perhaps this seven month old report is outdated and you can provide us with a more recient cite. Thanks

[opus]

I think a Thermo King is the way to go!

[wmkbailey]

Thermo King looks nice, but your'e still stuck with an engine driven compressor. Someone could make big money creating an AC system with both an engine driven compressor and a electric driven compressor. Or maybe a DC motor driven compressor that could run on engine or house battery.

[wmkbailey]

This is what we need.

The Civic Hybrid only uses the elecric motor when the engine is stopped. When you are moving the compressor switches to mechanical power from a belt.

Then we could run the AC from the motor while driving and the house battery when stopped.