Mini-split update

[lvmci]

Hi All, has anyone used this mini split system from Artic, designed for trucks and buses? Lvmci...


http://www.arcticbreeze-truckac.com/content/busac.html

[luvrbus]

Panasonic told Kenny the condensers need 3 ft from any structure and never install in a closed area he is trying to pull air from the bottom of the bay here the pavement in the summer time will reach 140+ degrees that causes him a problem  

Plus he has the condensers (3) in the last bay close to the engine compartment and the engine fan over powers the small condenser fans it's a constant battle for fresh air and he is tired of the battle like anything it will take time people will get it done by the old try and fail method it will just take time  

Fwiw the people that sell the units don't really care if they work or not in mobile app just give me the money is their motto  

good luck

[robertglines1]

How I did mine: 3 units  : 1st  condenser in spare tire compartment air in from behind bumper out thu  floor.. evap above driver seat  8 ft each of soft refrigerant copper tubing.  #2  mid ship  driverside  condenser in hvac evaporator compartment(no longer in use) forced  in from bottom side and out further up  thru same louvered door .Have not found a air recirculation prob when sitting still hear yet.  evaporator is connected by 10ft each of soft refrigerant grade copper tubing.  # 3 is located in the bedroom area facing rear.  is connected to the condenser by copper tubing 10ft each  located in the bus condenser bay which has the stock louvered door which I also elevated the condenser as high as I could drawing cool air in thru the bottom of the door and blowing discharge air out the top.. notice I did not say the underneath the bus or bottom of the bus.. When I mount  evap units I leave off level to drain end to aid in condensate drain..   This is a few things I have done plus total fastening of all line --telfon paste on fittings-- and 100% insulation on all copper.... strickly experimental!!!!!

[Oonrahnjay]

Hi All, has anyone used this mini split system from Artic, designed for trucks and buses? Lvmci...

http://www.arcticbreeze-truckac.com/content/busac.html 

      A lot of things about this look good, but 850W at 24V means a draw of about 35 1/2 Amp, nominal.  To cover surges and other things (low voltage, etc.) you'd need to plan on a working max of at least 42 Amps.  Even if there's no "start-up" current draw, you'd need to wire a supply and provide fuses for about 50 Amps/24V.  That sounds like a LOT of DC current to me.  I guess with the big 50DN alternators, it might be do-able; or maybe you could do 24V converter off 120 from the generator, but -- despite the small packaging and neat design -- I wonder exactly how practical this would be.

     I'd love to hear about some real-life experience with this system.    Bruce H    NC    USA

[Seangie]

I'll pitch in here with my experience to help along anyone who is watching this thread -

Here are some guidelines for the Mini-Split AC install -

1. First thing first - Insulation.  Nothing beats this.  Experienced bus builders on this board have said this over and over again.  Don't skimp on insulation.  Think about windows.  Put as much insulation as you can, use quality windows.  It will make all the difference in the world.

2. Airflow - The outside condenser needs to move alot of air to stay cool.  These compressors get pretty darn hot.  Mine (with the bays open) would get up to about 115 degrees on an 85-90 degree day in Florida.  With the bays closed (Bay door had a 3' x 12" hole with a grill and the bay floor had a 2' x 1' hole to vent air out) the compressor unit would hit as high as 125 degrees.  This temperature would stay lower if the bus was moving and I mounted an exhaust fan blowing air down through the bay floor that helped as well.  Whenever we stopped overnight I would always crack the bay door 6" to help with air flow.  Keep in mind that the excessive heat on these units greatly reduces their lifespan.  Now if you use your bus 12 times a year - might not be a problem but if you live full time in your bus and use it 24/7 the heat may kill the capacitors and other parts on the outdoor unit over time.  The best direction for airfow is to bring the air in from the side of the bus and down through the floor.  This is because when the bus is moving the pressure will be higher on the sides of the bus and lower underneath which will help the fan to do less work by moving the air in the direction it would naturally flow (as opposed to against the flow).  An air damper under the bus may help with this.  I have also seen pictures of buses that had the compressor setup on one side of the bay blowing air out the other side of the bay.

3. Linesets - This is where I had the most trouble.  Installing was a pain as it was post build.  Had I done it from the beginning it would have been a lot easier.  Make sure you wrap your lines well.  They will condense and lots of water will come from them.  The better wrapped the less water.  Also - A better wrapped lineset will also help to keep the cold side cold (better cooling when it gets to the evaporator) and the hot side warm (compressor doesnt have to work as hard to compress the freon) Also make sure your linesets are tightly fastened on the outside unit.  Mine kept coming loose - could be for many reasons, suspension, vibrations, damaged threads, overtightened, undertightened... but make sure you have a good solution for fatening the linesets.  They were not designed to be used in a moving, vibrating, bouncing environment.  Maybe sweating them on would help.

4. Evaporators - These units are awesome.  Super silent, programmable, they dehumidify, cool, heat and did I say they were QUIET.  But they also put out ALOT of water.  Easily a gallon a day of water in a humid environment.  Maybe more.  These units are not designed to be on a vehicle that goes around corners and bounces all over.  So make sure you have a good solid draining system for your evaporators.  If I installed these again I would take the evaporator unit apart and make some modifications to help with the drainage.  (higher walls, multiple points of drainage) Think about how you are going to install these units...they need to pull air from above (3' of clearance) and blow air across a 15' span without anything blocking the airflow.  Anything less than this and you are decreasing the life of the units. 

You get what you pay for.  You cannot expect that a cheap 500$ mini split in a bus is going to last you more than 5 years...and if it does then your doing well.  Also parts are not going to be readily available for a cheap unit.  If parts are available it would probably cheaper to buy another unit than replace parts.  If you spend the money for a "quality"mini-split you will probably be in the same price range as what it would cost for a crusair or marine/rv style unit that is possibly battery powered or self contained and will be warrantied and have better support.

My personal belief is that most of us on these forums are looking for a cheap solution that works better and more efficient than the similarly priced roof units.  I don't think spending alot money on a top dollar mini-split system for your bus is the way to go - Rather a known and tested system (like crusair or webasto) would be the better way to spend good money.

I may be regurgitating information here that i have already shared.  In future posts, I'll just reference this and  those other posts.  For what its worth, I am not an AC, Mechanical or Electrical engineer and these are just thoughts and experiences that i am sharing along with my own opinions.

-Sean

[Seangie]

     A lot of things about this look good, but 850W at 24V means a draw of about 35 1/2 Amp, nominal.  To cover surges and other things (low voltage, etc.) you'd need to plan on a working max of at least 42 Amps.  Even if there's no "start-up" current draw, you'd need to wire a supply and provide fuses for about 50 Amps/24V.  That sounds like a LOT of DC current to me.  I guess with the big 50DN alternators, it might be do-able; or maybe you could do 24V converter off 120 from the generator, but -- despite the small packaging and neat design -- I wonder exactly how practical this would be.

    I'd love to hear about some real-life experience with this system.    Bruce H    NC    USA

Bruce - Not to mention they suggest no less than (6) AGM batteries - I'm assuming that they need to be about 200-300AH each and at a cost of about 400-600 per battery just the cost in batts alone will be at least $2600

-Sean

Also to note - Any 120v AC will run off batteries if you have the proper battery and inverter setup.  Technomads Chris and Cherie run their roof unit off batteries.  They also have a huge bank of Lithium Ion batteries.

[Oonrahnjay]

Bruce - Not to mention they suggest no less than (6) AGM batteries - I'm assuming that they need to be about 200-300AH each and at a cost of about 400-600 per battery just the cost in batts alone will be at least $2600 -Sean

  Yeah, for mini-splits, I've been assuming that a bus owner would need a reasonably large generator (6K, 7.5K, 10K ?) generator or at least a 30 Amp shore cord supply when parked.  Obviously, this 24V unit is meant to be "stay cool for hours with parked with no external power" and thus the need for a big battery pack.  But, I see your point and agree with you.

Also to note - Any 120v AC will run off batteries if you have the proper battery and inverter setup.  Technomads Chris and Cherie run their roof unit off batteries.  They also have a huge bank of Lithium Ion batteries.  

   Yes, and any battery-powered-AC becomes an issue of "when and how and how often" do you recharge the batteries.  I can't think of a real-life situation when someone will make enough power and have enough battery capacity to charge while driving and still have AC until you're ready to drive again.  

   It's exactly these things that are among the set of complications and situations that makes me wonder if this unit (which is also fairly small) would be sufficient or appropriate for our needs.

[Iceni John]

      Yes, and any battery-powered-AC becomes an issue of "when and how and how often" do you recharge the batteries.  I can't think of a real-life situation when someone will make enough power and have enough battery capacity to charge while driving and still have AC until you're ready to drive again.  

When I install my 2,040 watts of PV panels (that will charge eight T-105 or L-16 batteries through two 60 amp MPPT charge controllers), I'll have a better idea how much usable power I'll have to run air conditioning.   Assuming the standard 0.52 derating for sun-to-AC losses, I should still get about 1,000 W of 120 V AC, about 8 amps.   It's not much compared to shore power or to what a big alternator can produce, but it's (I hope, depending on the weather) a constant, and I'll still be getting most of that even when driving.   If I can run one mini-split or window unit without pulling down the batteries I'll be happy.   We'll see!   Having lots of PV opens up some interesting possibilities.

John  

[Iceni John]

So this proves that 2kW of solar will run a 9000 BTU minisplit:  http://www.wind-sun.com/ForumVB/showthread.php?16163-What-a-quot-cool-quot-opportunity-load-)   And without drawing down the batteries at all.   Yeah!   My crazy plan may just work.

John