| Author | Message | ||
| Mark Murphy (Murphbass)
Registered Member Username: Murphbass Post Number: 1 Registered: 4-2008 Posted From: 75.41.124.132 Rating: N/A |
I've got an '88 MCI 102 which is used for a touring rock band. We travel with 10 people and are looking into rooftop A/C and power for the bus. It seems unlikely we'll find a generator that will fit in the old A/C bay, or at least one that will power (2) rooftop airs. We don't have the room for batteries as our bays are already filled with gear. One concept we're playing with is buying a Honda EU3000i for one air unit and an inverter for the other (maybe a Xantrex SW2524 or Magnum). It seems that every installer I've spoken with says that you can't run A/C off an inverter, though a lot of people on this forum say otherwise. Does not having a battery bank make a difference in this situation? Can anyone spot any potential problems or suggest the best way to implement the setup? Obviously we will only be running the A/C off of the inverter when the bus is rolling. | ||
| Luvrbus (Luvrbus)
Registered Member Username: Luvrbus Post Number: 355 Registered: 8-2006 Posted From: 74.33.36.66 Rating: N/A |
you need some type of a battery bank to run the ac of inverter then when under way the charging system will keep the batteries up if the alternator is large enough.but maybe some on the board will know of another way that will work for you good luck (Message edited by luvrbus on April 13, 2008) | ||
| James Robinson (Jjrbus)
Registered Member Username: Jjrbus Post Number: 120 Registered: 12-2000 Posted From: 68.243.128.77 Rating: N/A |
You have come to the right place. You have some misinformation! first you can eaisely get a genset that will fit and power two roof airs. Now will 2 roof airs be enough? You cannot operate an inverter without batteries. | ||
| James Robinson (Jjrbus)
Registered Member Username: Jjrbus Post Number: 121 Registered: 12-2000 Posted From: 68.243.128.77 Rating: N/A |
Opps, Yes you can run roof air off an inverter, I've been doing it for 6 years! | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 407 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Mark, Sorry to inform you of this, but there is no free lunch! Humor aside, inverters run off of batteries, and specifically deep cycle batteries. Electrical power is measured in Watts, which is Amps times Volts. SEER which is the efficiency measurement of air conditioners, is BTU per Watt. So, a 13,500 BTU 10 SEER rooftop A/C will draw about 1350 running Watts, which translates to about 12 amps at 120 Volts. This will require a 24 Volt inverter input of about 65 Amps, per rooftop, with slightly above average inverter efficiency. So, could you run two roof airs off a 4KW inverter off the chassis batteries while running down the road, (OTR)? Maybe, maybe not, probably. Your bus was built with enough alternator capacity to run the OTR evaporator and condenser fans, so it will certainly run one rooftop A/C. Can you run one A/C off a 3KW genset, and ONE rooftop off of a 2524 off of the chassis batteries while OTR? Definitely, just don't expect to run the A/C off the chassis batts for more than an hour with the engine off, and expect them to start the engine! Sorry to rain on your campfire, George | ||
| Jim Ashworth (Jimnh)
Registered Member Username: Jimnh Post Number: 506 Registered: 1-2001 Posted From: 72.185.82.200 Rating: N/A |
I used a 7.5K onan diesel genset to easily power 2 a/c's in the a/c bay of an MC-8. | ||
| R.C.Bishop (Chuckllb)
Registered Member Username: Chuckllb Post Number: 266 Registered: 7-2006 Posted From: 4.240.144.128 Rating: N/A |
Mark....there are all kinds of ways of "skinin' cats"... Your "gear" may be important; but is your comfort equally, or more important? One can isolate enough space for quite a number of batteries in a relatively small amount of space. Plan what batteries you want to use; quantity, height, width, etc, and you will find you can "cram" quite a few in a very small cubic footage. Use trays, rollers, perhaps stacked, as are ours and... wallah..... We have three start batteries, with room for 5, on one level...and 5 house batteries, not 8D, on a roll out tray above the start set. Height could be a significant factor in the Total number. We have an additional battery for the generator...at the generator site. Nine total. Not as much $$ as it may sound. (Sams)  FWIW RCB | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1253 Registered: 12-2000 Posted From: 76.69.141.132  Rating: N/A |
Hello Mark. You need a simple turn key solution. Your priority is the band, the bus is a tool that should take up as little time and distraction as possible. Busnuts love to add complexity, redundancy, efficiencies and prove that things can be done that others say can't. Cost benefit often does not enter the equation You have a business to run. I would recommend a big enough generator to power your needs and be done with it. Never mind the inverter, or tying into the bus systems. If you want AC, run the generator. If not, shut it off. On the road, or parked. Have it installed in the AC condenser bay, it will fit once the AC parts are out. Add some sound insulation. Get a newer diesel generator, and tap the coach fuel tank. Have the pick-up cut so that it leaves 4-6 inches of fuel in the bottom of the tank so you don't run the fuel tank dry with the generator. Install an easily accessed fuel primer bulb in the line. Someone WILL run it out of fuel... You will quickly identify at what point you need to fill the tank to keep the generator happy. Wire up the roof airs and you are done. The diesel generator may cost more up front, but it holds its value for future resale, if things don't work out. If you use another fuel type, you'll have to put the fuel storage somewhere. Consider carefully the danger and pain in the behind of less than inspired band members messing around with fuel cans out in the rain, etc, pouring it into a hot machine if you go small portable gas generator. Wrico on the west coast has a number of packages just for this kind of application. Others chime in with your sources. happy coaching! buswarrior | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 293 Registered: 10-2006 Posted From: 66.90.226.106 Rating: N/A |
The Honda RV unit will run 2 airs no problem. I would install the propane unit as the NOISE! is 1 /100 of a diesel,the exhaust doesn't stink as muchand the unit can be off for months with no maint required. Propane doesn't die in 30 days like Fed mandated gasoline , or fill carbs with gunk from non use. FF | ||
| Richard Bowyer (Drivingmisslazy)
Registered Member Username: Drivingmisslazy Post Number: 2045 Registered: 1-2001 Posted From: 75.108.85.14 Rating: N/A |
The genset needs to be large enough to do more than run two roof airs. With that number of people aboard someone will want to use the microwave or toaster or other electric consumer items. Also with that many people aboard, two roof airs may not be enough unless the bus is extremely well insulated. I would plan on a 10kw DIESEL only. Either a gasoline of LPG genset will prove to be a large pain in the @ss every time you have to get fuel. Richard | ||
| JR Lynch (Njt5047)
Registered Member Username: Njt5047 Post Number: 231 Registered: 7-2006 Posted From: 70.61.104.58 Rating: N/A |
Here's sample of a diesel 120/240V genset that will both fit into the condensor compartment and operate two rooftop ACs. The genset is a Yamaha EDL6500. I carry one bay full of music instruments so the goal was to keep at least two bays open. The little sucker required a good bit of soundproofing, but otherwise has worked well for 5 years now. This type of install obviously requires losing the OTR AC. JR  | ||
| Mike Eades (Mike4905)
Registered Member Username: Mike4905 Post Number: 168 Registered: 12-2000 Posted From: 68.200.183.92 Rating: N/A |
Talk to Dick at Wirco and ask a pro. I run two off of his unit. I can run my washer and dryer and one ac. I wonder if two 15's are enough for the people you are talking about. Mike | ||
| FAST FRED (Fast_fred)
Registered Member Username: Fast_fred Post Number: 294 Registered: 10-2006 Posted From: 66.90.226.9 Rating: N/A |
Simplest solution ,with such large power requirement might be to simply tow a 20KW or 30KW unit. The noise and stench will not be a bother , and the unit can easily be left at the dealers for maint. FF | ||
| joe padberg (Joemc7ab)
Registered Member Username: Joemc7ab Post Number: 231 Registered: 6-2004 Posted From: 66.38.159.33 Rating: N/A |
A lot of guys in rock bands have their hearing impaired, so the noise factor might not be an issue. Joe. | ||
| joe granzier (Joegranzier)
Registered Member Username: Joegranzier Post Number: 13 Registered: 3-2008 Posted From: 69.250.215.101 Rating: N/A |
Well said, by the buswarrior on 4 points 1. You have a business to run - keep it simple(kiss) 2.While the engineering resources we have on this site are a terrific / resourceful source of information - cost benefit doesn't always factor in the equation. 3.Tap the existing fuel tank - the cost of plumbing ,securing and monitoring another fuel tank .aghh 4.Add the prime bulb - someone will run it dry. Nice words of advice - this is a well run site | ||
| George M. Todd (George_mc6)
Registered Member Username: George_mc6 Post Number: 408 Registered: 8-2006 Posted From: 207.231.75.253 Rating: N/A |
Joe, Thanks for the thanks, we do try, and we really appreciate thanks! I didn't do a real good job on my first post, because I left out a word of caution, inverters put out a lot of heat! An inverter running one roof air is going to put off about 4600 BTU, so it can't be in a closed bay!!! We also don't knnow if he needs air while parked, which definitely changes the equation... George | ||
| Mark Murphy (Murphbass)
Registered Member Username: Murphbass Post Number: 2 Registered: 4-2008 Posted From: 75.8.109.204 Rating: N/A |
Thanks for all the good info. I'm glad I was set straight about inverters- I thought you could run one off of the alternator. I especially appreciate the posts which take into account that money is an issue and we need a low-maintenance operation. One question: it looks like installation of the roof top airs may be out of our budget, so we are considering a free standing unit. Does anyone have experience with one of these? | ||
| Buswarrior (Buswarrior)
Registered Member Username: Buswarrior Post Number: 1275 Registered: 12-2000 Posted From: 76.68.134.62 Rating: N/A |
Hello Mark. If roof airs are out of your budget, you're playing a losing game. Roof airs are the quick and dirty, cheapest way to get a box on wheels to cool. That's why all the RV's have them. You can be sure that if there was an adequate way of more cheaply cooling a box on wheels, the RV industry would already be doing it. There's no free lunch. If you get $120 out of each of 10 band members, there's your roof airs with change left over to pay someone to run the wiring. Same strategy to pay for the generator. Pretty easy to add up current operational costs (motels, restaurants, mileage on vehicles, discomfort of no AC) to see a break even point a very short time in the future, if the bus is upgraded to support living in it while on the road. Are you charging enough for your music? happy coaching! buswarrior (Message edited by buswarrior on April 23, 2008) |