I've been debating how to arrange the equipment in our cargo bays. Currently I am trying to figure out if I can stick a generator and a 25 gallon aux tank in the street side of the front bay and put the house battery setup on the curb side of the same bay. We are planning to keep the OTR air, so the condenser space is not available.
Thing is, generator and fuel has me close to 1100# and I've only found one reference so far to the capacity of the bays and it suggests a 1200# limit. I can and will probably be able to save weight by removing the gen enclosure and going with some ROXUL insulation on the walls of the bay for sound dampening and fire control, but the amount of weight savings is currently an unknown.
Is locating the gen in the batteries in the same bay a possibility or just out to lunch? I do not know how many batteries I will end up using for the house set, but I believe that we are looking at at least a couple hundred pounds for just the batteries. (4 GC2 batteries at ~65# each is about 260# and guestimates at 430AH @ 12V)
Keeping the OTR A/C sounds good on paper. BUT-you're wasting space with all the ducting, condenser, fans, evaporator, etc. AND when it breaks down (and it will) it costs alot to fix. Most of us remove the OTR system and only keep the front heater for defroster and possibly install a dash air. I have 3-13,500BTU Coleman roof airs running off a 10kw Diesel generator. Most of the time 2 do the job. When it gets above 105 outside, then the third is kicked on.
With the OTR A/C removed, now you can use the condenser bay for the generator.
Batteries need to be in a compartment with ventilation and easy access. Tanks can be mounted near the center. Most keep at least one bay open for personal junk. Your floor plan will determine many of the placements of the equipment in the bay. Good Luck, TomC
Do not forget all the fun calculating the final load out on each axle and each axle end. Fun. Ideally when all said and done you should be within just a few pounds from being exactly correct.
An example for a two, (2) axle coach would be around 33%+- for the front with a 50%-50% perfect balance side to side. That would mean the rear single axle would have about a 66%+- on both ends.
Again with a perfect 50%-50% balance. Then it gets more fun as the dynamic balance would change as one consumes diesel fuel and water; rearranging the water partially to the gray and black tanks.
For more fun consider where everybody will sit, how much they weigh and how often they will move around. How much does fat ANNE weigh? It all makes a difference. Try to get as close as you can.
Ideally all of this will happen on paper before any major installations or changes are made. You would be amazed how many very nice Bus Conversions are extremely unsafe due to poor distribution.
Some things are heavy. Some things are quite light. Some things move around all the time getting relocated or dumped. Some passengers can not sit still. It all makes a small or big difference.
Not quite completely serious but you get the general idea. All part of the fun and madness on converting that Bus Conversion into that ultimate high performance motor home. Hard to do.
Right now I still have the factory Aux. fuel tank in first bay, centered on back wall. I mention this because your decision to keep OTR hvac which is fine there's several that have it. As i hear and understand traveling in the winter then it could be real benefit.
Its a good weight balance consideration with the batteries, opposite bus side if I understand correctly that sounds great. I'm thinking a bit easier access to that evaporator, heater core and double squirrel cage might be nice in my 2cent op.
Whats your thoughts using the 2 bay is that possible.
good day there
Floyd
I'd say that as soon as you have to worry about weight, you're putting too much in.
Why does everybody want to load their busses down with heavy stuff?
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Right off the bat, our buses are WAY heavier than sticks and staples motorhomes. I've been looking at motorhomes and I see gasoline powered motorhomes are getting more popular (which means Ford chassis). Many have a 22,000lb gvw for totally loaded. What a joke. My bus weighed 28,000lbs as an empty shell. Now weighs 31,000lbs. Even pulling my 3,750lb car, I'm not over the 36,000lb (13 front 23 rear) gvw. I'm at 10,500lb front, 20,500lb rear. Good Luck, TomC
Quote from: TomC on August 26, 2017, 06:41:33 AM
Right off the bat, our buses are WAY heavier than sticks and staples motorhomes. I've been looking at motorhomes and I see gasoline powered motorhomes are getting more popular (which means Ford chassis). Many have a 22,000lb gvw for totally loaded. What a joke. My bus weighed 28,000lbs as an empty shell. Now weighs 31,000lbs. Even pulling my 3,750lb car, I'm not over the 36,000lb (13 front 23 rear) gvw. I'm at 10,500lb front, 20,500lb rear. Good Luck, TomC
Mine has a GVW of 27,500. That's 10,000 front and 17,500 rear. The chassis and so on could probably handle more because the same exact chassis and engine etc are used on the Wards. That's 72 passenger as opposed to my 56 passenger. I'll be amazed if my additions weigh more than the removed seats. The lumber I used is 2x4 and osb.
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Thanks for the info!!
I hadn't really given much thought to axle loading (rookie mistake I suppose) because I had thought that removing all the seats, luggage racks and most of the windows (to be replaced with RV windows in some cases), would offset most of the weight changes in the interior. If the additions were heavier, it would be located in the bathroom and kitchen and therefor between the axles. However, I had wondered if I shouldn't just build out the interior, then weigh it and use the basement equipment placement to balance everything out as much as possible. This would make pressure testing the fresh water piping, before closing up walls, a little more difficult, but not impossible.
Currently, none of the locations for anything in the cargo bays are set. Except, the black tank will be under the toilet. Everything else is just a matter of running wires and piping.
From most of the discussions I have seen on the OTR AC, I think I've read most of the pros/and cons for both sides of the argument. Our plans in this department are not set. I like the simplicity of not having to rip the system out and alter or otherwise replace the system, but it has more capacity than I think we will need, want, require or desire once the bus has been better insulated and the number of windows reduced.
I have considered looking for a smaller engine driven compressor to run just the driver's AC. That would allow for a smaller condenser, and should free up enough amperage that we could use a 24VDC to 120VAC inverter to run our front rooftop unit. It should also allow me to enlarge the current battery compartment and use a slide out tray to co-locate all of our batteries and make them accessible.
Zeph, we do not want a minimalist approach for our conversion and our budget wont support an "only the best of everything" approach, so we are aiming for somewhere on the reasonable side of the middle. In the past a Jeep with a cooler, hammock and a tarp was more than enough for me to get away from the world for a few days. It still would be, if it were just me. For a family of four, it will take a little bit more in order to be able to get them out to see the country for a few weeks or so at a time.
It is fun to sit down and dream sheet. Then select the stuff you need and the stuff you want and the stuff you would like to have. Like all engineering endeavors, (Bus Conversions are no different) there are many compromises to be made.
Most are economic. Some are structural. A few physical. Quite a few ignored. The end goal is a Bus Conversion that works all of the time extremely well. Sometimes crowding in the options is not physically doable. Again, weights and balances.
Weight imbalances can creep up on you. Hanging that 7.5 KW gen set 48 inches behind that rear axles(s) can screw up the weights and balances of the entire coach. Big sets of house batteries, (all electric coach) can seriously affect road performance.
The fun and easy solution is to calculate all the affects of various interiors gadgets ahead of time. Sometimes you must physically weigh the things, then determine where and how they must fit in. Easy to overload single bays or entire coaches.
Also easy to forget the people load out. How many passengers and crew? The usual. The occasional? Six adults can weight over 1000 pounds. Makes a difference. Again, fun and easy to sit down beforehand and figure it all out. Are we having fun?
Is it worth keeping the OTR A/C since it can only be used while the engine is running. Since you will be parked 90% of the time, you will mostly be using roof A/C. Also, a big alternator with well sized inverter would permit to use the roof A/C while on the road.
So, i guess you should use the the two OTR A/C bay for propane and battery.
My opinion...
I consider it very fortunate that the previous owner(s) of our bus left both the OTR a/c and heat intact. I can't imagine having to rely on running the generator every time I decided to head down the road. I'm already putting wear and tear on the main engine, and I wouldn't want to add needless wear and tear on another engine (which is difficult to access and expensive to repair.)
Richard
Running the generator (I have a 10kw 4 cylinder Kubota engine by Powertech) going down the road isn't that big a deal. Granted it does burn more fuel, but you don't really hear it, and when you stop, the generator just merrily keeps running keeping the bus cool and you can turn off the big engine. I am not sorry in the least I don't have OTR engine run A/C (actually my bus did not have it since it was a Portland, Or Metro bus). The three roof top A/C's have been literally zero maintenance (except cleaning the filter) since installing in 1994. I'm quite sure your OTR A/C could not be zero maintenance for that many years.
My generator has about 1,500 hours on it (no repairs on it since installing in 1994, except changing oil and coolant)-which isn't much considering I had a truck driver friend that his generator had over 23,000hrs on it when he sold his truck. Good Luck, TomC
Im not sure the best decision, each has to make it and run with it.
Figuring fuel both use it, so how to determine the qty of the otr system probably has specs. somewhere.
My kubota 4cyl seems to use for now 1/2 gallon an hour on its hour gauge.
Floyd
HB, I always have fun or I take a break and do something different for a while. Reality has already nixed a few things from the "dream sheet". Practicality, like you said, will claim a few more. The more we work on 'the math of the dream sheet', the more something my HS economics instructor said comes to mind: "There is no such thing as a free lunch." Everything has a trade-off.
A/C is no exception. Remove OTR AC, gain weight savings and release HP back to the engine. Still need AC, so take engine HP, or get that HP from somewhere else and turn it into cold air. Theoretically you save, partially because you can't create the same amount of AC with the other options available. The more parts that go between your AC and your HP source, the more inefficiency you add.
Tom, maintenance on an ac system or additional maintenance on a generator and potentially a battery system. Based off of some of what I've seen for prices for parts for either, it looks like two sides of the same coin to me. If you are unable or unwilling to do your own maintenance, that is something that should be factored in that may make one choice more favored than the other. If you were not offered the choice, then the answer is less complex.
Magnolia, we may only spend "10%" of the time traveling to our next parking spot, but that 10% is how the trip begins and how it ends and can have a larger impact than you think. Also keep in mind, if you are sweating your hind end off, then your attention is not 100% on the road in front of you and what the other drivers are doing. If your passengers are uncomfortable, they will let you know, sometimes to the extent of being distracting.
To veer back into the general direction of weights, balances and bay layout, I am interested in feedback on lateral balance of the bus. With our side door, we are looking to keep the door available and change from a central hallway floor plan to one with a side hallway. Seems like a hallway down the passenger side wall, would inherently create some inbalance. We've seen some floor plans with the side hallway, but very few actual conversions like that. Do you just cheat your tanks to the passenger side and use water like ballast? If you do, and your tanks are dry from storage, do you just cross your fingers and head towards the nearest water source to ballast up? Do you just make allowances with finish materials and use a fiberglass and acrylic surround instead of the tile and glass. Personally, the porcelain throne is non negotiable. If I must, I will account for it elsewhere.
Nett reduction of 40 seats at 100 pound each, 40 passengers at 180 pound each and 40 sets of luggage at 60 pound each means you have a lot of slack in the system so generally there is little need to turn yourself into an airline pilot and do a weight and balance calculation.
Stories relate 8V71 engines being carted around the country in the luggage bays so I doubt whether their capacity would be a concern either. I have a tonne's worth of water and waste tanks plus water tanks and large pressure accumulators in my rear bay and it is taking the strain OK.
Original OTR air conditioning is in place and working and I wouldn't be without it in the Australian summers. With all the front glass and air entry around the driver, roof airs wouldn't come close to keeping the driver comfortable, but by modifying the duct work (I pulled all the side wall air diffusers and panels out) and aiming some serious amount of cold (or hot) air forward, I can be perfectly comfortable whatever the outside conditions
Quote from: Tony LEE on August 26, 2017, 11:50:27 PM
Nett reduction of 40 seats at 100 pound each, 40 passengers at 180 pound each and 40 sets of luggage at 60 pound each means you have a lot of slack in the system so generally there is little need to turn yourself into an airline pilot and do a weight and balance calculation.
Stories relate 8V71 engines being carted around the country in the luggage bays so I doubt whether their capacity would be a concern either. I have a tonne's worth of water and waste tanks plus water tanks and large pressure accumulators in my rear bay and it is taking the strain OK.
Original OTR air conditioning is in place and working and I wouldn't be without it in the Australian summers. With all the front glass and air entry around the driver, roof airs wouldn't come close to keeping the driver comfortable, but by modifying the duct work (I pulled all the side wall air diffusers and panels out) and aiming some serious amount of cold (or hot) air forward, I can be perfectly comfortable whatever the outside conditions
I'd imagine it'd be like driving a schoolbus here in South Carolina. I have AC but it doesn't reach the front. By the end of a 3 hour afternoon trip, my trousers are moist from my wiping sweaty hands on them, my shirt is soaked and as my rookie driver commented when I encouraged her to learn some of the route by driving, even the seatbelt was wet.
I have to drive with a bottle of water by my elbow.
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OTR A/C is great for sure. But it can be expensive to maintain. In charter service, it is the most expensive maintenance item to keep going every year. When I looked after the hockey team's 102D3, we spent $1000 to $1500 a year fixing small leaks and recharging every year. None of us knew anything about refrigeration, so we took it to a specialty shop. It would pay to gain some knowledge, and have the tools to maintain your own.
JC
Quote from: lostagain on August 27, 2017, 06:45:52 AM
OTR A/C is great for sure. But it can be expensive to maintain. In charter service, it is the most expensive maintenance item to keep going every year. When I looked after the hockey team's 102D3, we spent $1000 to $1500 a year fixing small leaks and recharging every year. None of us knew anything about refrigeration, so we took it to a specialty shop. It would pay to gain some knowledge, and have the tools to maintain your own.
JC
My understanding is that AC is a really simple device. Two coils with a tube connecting them that has a very narrow section. The other side is a pump. The narrow tube is there to restrict gas flow so that with the pump on, the one side is low pressure and the other is high pressure. The high pressure side expels heat and needs a heatsink and or a fan. The low side absorbs heat. Controlling the pump are a timer and a thermostat. The thermostat kills the pump when the air temperature is at the required temperature. The thermostat itself is just a bimetallic strip that curls more at higher temperatures and the knob just moves a contact further or closer to make or break contact at different temperatures. The other thing is a timer. Every 20 minutes or so the system shuts down for long enough to clear the low pressure coil of ice and water. That then drips into a collection bucket.
Many times I have considered building my own AC unit. The killer is the cost of the coils. Refrigerant is cheap enough. In fact, most any gas will do as long as it's free of water.
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On my Kenworth truck, since my 8ft square drom box (that I converted into a sleeper with shower, toilet, refer, microwave, sink, bed) was nearly 13ft 6", did not have the room for a roof top A/C. Nor was I going to be running the big 14.6 liter Caterpillar all night to use the dash air (I always think it is such a waste to run the big engine when a small APU works fine for night heat and A/C). So I built my own A/C.
It was simple-I bought the duplicate evaporator, receiver dryer, 12v blower, compressor that was on the truck. For condenser, I bought one was used in a Toyota Celica-fit my space. And for condenser fan, bought a 12" reversible 1/4hp 120v fan from Grainger. Then I added a cable operated thermostat, and three speed fan control. I have (still have) an Onan Emerald three commercial 6.5 gasoline generator (truck had a separate 75gal tank) with PTO shaft coming out the rear of the alternator to belt drive the A/C compressor. I usually only ran the blower on medium or low speed since the A/C was so powerful, you could hang meat inside. Served me faithfully for 12 years-course it was the old R12 freon too. I just never heard of the timer. Once the air gets down to temp, the compressor cycles anyway. Good Luck, TomC
Got me wondering just how my coach was weight distributed. Looks pretty thought out. If you can't see the image link let me know
https://www.dropbox.com/s/jckov2ddquoyt8w/IMG_20170827_094207.jpg?dl=0 (https://www.dropbox.com/s/jckov2ddquoyt8w/IMG_20170827_094207.jpg?dl=0)
Very well done sir. Curious as to why you did not weight each axle end?
Respectfully.
if you put the heaviest loads in the center bay...both axles will be stressed equally.
That seems the easiest way to get it right...
worked for me.
irrc Trailways shipped long block 8v71's in the center bay.
Quote from: HB of CJ on August 27, 2017, 10:56:58 AM
Very well done sir. Curious as to why you did not weight each axle end?
Respectfully.
the weigh station was not set to do each wheel,as it was it took two measurements to get the front and the rear. Ido plan on getting the weights on each wheel, meanwhile the readings are sufficient for the inflation tables.