| Author | Message | ||
| Jim (Jim_in_california)
Rating: |
As y'all know, there's a LONG thread regarding finding a way to use the typically massive bus AC unit while the bus is parked and the main motor shut off: http://www.busnut.com/bbs/messages/11/8955.html?1106367994 The main consensus at least when it was around 45 posts long is "no way". And my purpose isn't to rehash that. It's to ask a question related to that: if it's possible to cool a good 40ft bus conversion with a pair of good-sized roof ACs that together can be fed with a 6.5kw genset or a really good alternator off the main engine, and the genset plus roof ACs combined don't weigh as much as the 500lb+ pound monster AC units, why didn't the factories go that route to start with? Well...apparantly, and this is just what it looks like to me, that monster AC unit from hell is still cheaper than the cost to properly insulate the bus! Holy crap. It means we REALLY have to pay attention to proper insulation and shell prep, esp. newbies on their first bus who might not understand this. There's lots of "bus conversions" out there where it's obvious they've got the factory roof, factory windows (all of 'em) and probably minimal prep to the walls if any...but all the rest of the bus is great, good insides and layout, good paint, body, drivetrain...but despite good looks, it's "just a hippiebus" as one pro converter put it. Very, very interesting, at least to this newbie. Damned glad I did enough digging to learn this before spending cash. | ||
| Brian (Bigbusguy)
Rating: N/A |
I like it "Hippie bus"  I guess Im not in the Hippie bus class but close to it. No side windows at all I will cut out for 7 duel pain windows as I afford them. I will have lots of insulation and under the floor also. I think older buses with out the extra 100 sq.ft of windshild glass will be easer to heat a cool also. So my cheep to buy redone window AC's will do just fine . You will not see them sticking out a window. I guess what looks good to one will look Hippie to some one elese. Brian 4905 Klamath Falls Oregon | ||
| FAST FRED Rating: N/A |
"It's to ask a question related to that: if it's possible to cool a good 40ft bus conversion with a pair of good-sized roof ACs that together can be fed with a 6.5kw genset or a really good alternator off the main engine, and the genset plus roof ACs combined don't weigh as much as the 500lb+ pound monster AC units, why didn't the factories go that route to start with?" Because the design requirements were VASTLY different for a Pax bus than for an RV. For one the coach needs to be cooled in any area of the country in a SHORT time . At a rest stop the engines were usually stopped (to keep from killing the population with DD fumes) and the coach would need to get cool , full of 350W output sweating humans as fast as possible. The air cond was unmodulated (in GM) and use engine heat to controll the intereior temps. Very fine at removing moisture from the cabin , but seldom needed in an RV. The FACTORY insulation and stock glass works quite well wint only 2 rooftops on any 35 ft RV ,IF the ROOF IS WHITE! Dual glass windows may keep some noise at bay , but doubbling almost nothing as an R value doesnt do much for insulation. HOW you chose to power the rooftops is Your Way, FAST FRED | ||
| T. (Bluegrass)
Rating: N/A |
Bryan I would not be 2 worried about It being a Hippy Bus, I know a Guy that has a 56 Flex that has a window air conditioner In the hump on the back of his bus and It does a fine job cooling the Flex this bus was originally converted by custom coach In Columbus Ohio the guy has put one of the sweetest sounding 3208 Cats In It that you have ever heard. do It our way right. Tony | ||
| Richard Bowyer (Drivingmisslazy)
Rating: N/A |
snip: At a rest stop the engines were usually stopped (to keep from killing the population with DD fumes) I do not ever recall a bus engine being stopped at a rest area. They were not even stopped when at the terminals. My general understanding is that the engine was never turned off from the time the bus left its originating point until it reached its destination and went to the barn for fuel and/or service. And where do you come up with this BS of people getting killed from DD fumes? I have never even heard of anyone getting ill, let alone killed. How about some references. With the hundreds of trucks ideling every night at truck stops thruout the country, it seems that if that was a problem we would have heard about it vrom someone besides you. Richard | ||
| John that newguy Rating: N/A |
Well Jim... As far as insulation... An insulated roof (even a coat of rubber) helps. Removing 1/2 of the glass windows also helps... and tinting the balance of the windows will help even more..... for the southern states and especially Florida. For the northern climates, you would need to insulate the walls and floors as well as the roof, if you want to contain as much heat as you could inside the bus.. And the tint would work against you... The massive AC unit and very well designed heating system of a bus would suit any condition of the "conversion". The entire heating system can be run from the engine, or an auxiliary hot water heater.... Webasto, Propane, electric... The air conditioning is the problem.. That bus AC compressor is designed for the bus and that massive system in that bus. Two RV rooftop air conditioners can never match the output of that massive system. But since you're not loading it with 50+ people, and keeping all the windows, you may get by with a much smaller system. The insulation in the bus isn't much worse than the insulation of the average commercially built motorhome. Down here in Florida, you'd run into some problems getting and keeping the bus cool after it's sat in the hot sun awhile. On the very hot days, you would need both AC units running constantly. That's when the bus AC would come in handy. You'd be able to cool the bus and all that's in it quickly, making it easier for the roof top AC units to keep it cool. Houses down here are well insulated. Try sitting in one in August without the 2 ton AC running... An RV rooftop unit is about equal to the average window unit.. You're not going to feel all that cool in any 1,900 cubic foot room in a Florida home on a hot day, using a small window AC unit. Now imagine insulating a bus with as much insulation in the average Florida house.. Insulation may help, but removing windows and tinting the balance will help more.... and adding anything to the roof... reflective paint, a rubber coating... will also help greatly. There's no need to go nuts with insulation, unless it's around your pipes for extreme winter conditions. After speaking with 5 owners of "deluxe motorhomes", I've come to the conclusion that basement air conditioning is very inefficient. Cold air falls, not rises, so the cooled air must be forced to the top of the motorhome and circulated. Since heat rises, it's more difficult to keep the motorhome cool with a basement system, than ceiling ductwork. After removing the ductwork from my MC9, I decided to keep the original system. I'll use the vent holes, but no duct work.. I'll add the roof-top AC units if I can't use my existing "Welch system" with an electric motor. http://www.welchindustries.com/convkits.html And I may add wall-to-ceiling ductwork to dispense the cold AC air, rather than just have it blow out the front floor vents. I do not plan to add insulation to the roof, or walls, but will be adding some to where windows are removed and to the rear bedroom, over the engine. I'll worry about cold weather if we decide to travel north into New England during the winter (probably never again). | ||
| John that newguy Rating: N/A |
Richard- Although FF can exaggerate at times......Many localities have passed legislation to stop the unnecessary idling of engines. When I drove, the bus usually ran from the time we left the barn to the time we returned. For the ski trips, I needed the heat; for the summer runs, I needed the AC.... But hell, that was back when the operator didn't pay that much for fuel... Back then, it was perfectly OK to drop the charter group off and go sightseeing in private, using the bus... I don't know what the policy is now.... (I don't know if any "bus nut" is on Long Island, but if so... can ya' say "hi" to Smitty at InterCounty? He was a great guy to work for... http://www.gointercounty.com/ ) | ||
| Johnny Rating: N/A |
"An RV rooftop unit is about equal to the average window unit." Not on your life. A normal window A/C is 5000-5500BTU, a big one is ~10-12K (my big 220V Fedders is 12,000). Roof A/C units are 13,500-15,000BTU's. | ||
| Tim Strommen (Tim_strommen)
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Hey, I don't mean to seem like I'm tootin' my own horn, but on the topic of A/C and heat as related to climate control in a bus, Ian did post an excel spreadsheet I wrote for all of you guys to use. It should help you guys get at least an idea of what the effects of insulation, temperatures, and occupancy should have on your setup. http://www.busnut.com/bbs/messages/11/7288.html?1097506171 Cheers, Tim | ||
| Jim (Jim_in_california)
Rating: N/A |
Tim, toot away, that is a KILLER spreadsheet . | ||
| Brian (Bigbusguy)
Rating: N/A |
I can get it to work with the free excel Im not going to pay $200 + to get one is there any other way? I dont plan to build my bus like some have said they are doing Cant go there to cold or to hot. Thats just a lazy way of converting a bus. You should be able to go any where any time of year even if you dont it would be nice to know you could if somthing come up and still live in it comfortable. Things happen things change and you could get stuck some place that gets very cold at night. I guess you would not to visit here in July It snowed here one year on the 4th of July. I guess you could burn your flexsteel sofa to keep warm ha ha ha. Heat is easy to put in a bus AC is harder I sure my window AC units will work you will not see them and 2 of the 3 will be up high so the cold air will flow down . Still in the planning stage I may go with split air or last roof tops  . Brian 4905 Klamath Falls Oregon | ||
| James Maxwell (Jmaxwell)
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Johnny: A small window a/c is 5000-6000 btu; in fact I'm not sure they make a smaller one. A large one is 24000-30000 btu. Avg. is probably as originally stated, 12-15k BTU, same as the roof units. On the other hand, the avg. central unit for most 40' buses is 90-110,000 btu, with 45' buses packing a unit designed at 120-130k btu. I'm not familiar w/all the newer units out there, but the ThermoKing 6 cyl. compressor is rated at 15 ton, 180k btu, 2100rpm. The 4 cyl. is rated 12 ton. Coils are generally sized below the compressor capacity out of oil return considerations. | ||
| Johnny Rating: N/A |
I have an old 4700BTU Westinghouse for my bedroom. "Average" here seems to be ~8-9000BTU. I have NEVER seen anything over 18,500. | ||
| James Maxwell (Jmaxwell)
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Johnny: Nevertheless, they do make them up to 30k that I have seen (Home Depot, made by Fedders). And yrs. ago I used some body pack units made by Sanyo of 400 btu size, rotary compressor, R-12. Operated on a 12v battery pack for about 2 hrs. You could use them with just head hood or the optional full body suit. I primarily used them for working inside steam powered absorbtion system shells. Even w/the steam shut off, they easily ran to 130* and above even after sitting overnight shut down. They actually made it tolerable up to temps of abt. 150. | ||
| John that newguy Rating: N/A |
Jim- Thanks. Brian- re: "I dont plan to build my bus like some have said they are doing Cant go there to cold or to hot. Thats just a lazy way of converting a bus. You should be able to go any where any time of year even if you dont it would be nice to know you could" One of the neat parts of building our own RV, is the benefit of doing it to suit our own needs. Our Winnebago's pipes froze in the winter regardless of how much heat I had going. Our Georgie-Boy's drain pipe froze only once during the entire New England winter. It wasn't the amount of insulation, it was what was insulated and where it was insulated. So....... why bother to use max-r insulation throughout the RV, if it's not going to make rat's rear as far as your plumbing's concerned? What good is using a few less BTUs, if you're going to be outside with a heat gun, trying to get the ice out of your black tank? During some of the hottest days in Florida, our MC9 with it's windows and roof vents open, was comfortable enough to sit in. In the 40 degree weather we're having now... one small electric heater keeps it too warm to work. The bus body is insulated as well as any RV I've owned, so why add more? I'd prefer to add it to pipes and plumbing; to the needed and necessary items that are subject to freezing. Insulated hot water pipes and air conditioning duct can do more for comfort and cash savings, than any amount of high $$$ insulation added to the entire structure. And although foam sounds great sprayed inside every wall, like so many guys are doing.... have you ever tried to make a repair to a foamed item? Have you ever tried digging wires or plumbing out of a foamed compartment? And the moisture it can hold? To each our own, Brian. But just because a guy doesn't do his bus in the design you do, doesn't make him lazy. I think I speak for more than myself, on that point. | ||
| Brian (Bigbusguy)
Rating: N/A |
John, Thats the point. Making sure your pipes are insulated and so is the bay you have it all in. I few extra days of extra planning and insulating is not that much to do . Some people just toss the lawn chairs in and cover the windows and call it good. The main reason most people replace the stock insulation is its crap . And some times wet or been wet. I like to have all of my cars trucks or bus set up so I can go any where any time . When I get my bus finished If I want to go to Reno NV. in January I can and not have the pipes freeze. There is a lot of ways to do a bus I dont care how someone does there bus . But some times it dont cost any more with a well planed bus to not have froze pipes or tanks. Do it you way Il do it my way . And every one will be happy. Brian 4905 Klamath Falls Oregon | ||
| FAST FRED Rating: N/A |
"But some times it dont cost any more with a well planed bus to not have froze pipes or tanks. Do it you way Il do it my way . And every one will be happy." Easiest way to accomplish this and have a SEVERE WEATHER coach (even if only as resource for emergencies) is to NOT use the bays as a basement . By simply building everything that can freeze INTO the coach , rather than under the coach , problem SOLVED! AND you get to carry stuff (the American Disease TMS "too much stuff") in the bays , instead of 400gal of black water. Works for me, ( and Yes it does take a bit of planning and better building skills , but no more money) FAST FRED | ||
| Jim (Jim_in_california)
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Huh. You know Fred, you have a point there. Fresh is easy, you stick that under the main bed. Lesse...the toilet itself does NOT need to be on the same level as the main floor, does it? So...jeez, lift the whole toilet stall a foot and a half, maybe even two feet, have it maybe 40" long by 32" wide or so, and yeah, there's your black/gray combined water right underneath! Problem: to drain the shower (and maybe even kitchen sink?) you'll need a 12v pump but...shrug, who cares? And...wiping yer tushie might get slightly contortionist for us tall folk... . (NOT as bad as the time I broke both my arms in a motorcycle wreck. THAT got annoying.) Hmmmmmm. <scratcheshead> OK, where *else* could that durn tank go? Under the kitchen sink? Raise one of the couches in the living room...? | ||
| Johnny Rating: N/A |
Mine are going under counters & shelves. | ||
| Brian (Bigbusguy)
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My plan is to have every thing in the 3rd bay nice to not have a extra axle not needed any way. I will have the bay well insulated and all pipes insulated . All my pipes will come up from that bay .And Im planing the pipes in side the coach will be inside a 2" pipe that leads back to the bay so if any thing leaks or busts any water will drain back to the bay and not on the floor . That is still just a plan I will see how that works out. The bay will be easy to keep it heated or have tank heaters . That way I have a As FF says "SEVERE WEATHER coach (even if only as resource for emergencies)" . But with the use of a bay I dont want poop tank inside my coach. I would say planning starts with the bus you buy . But the best plan is to plan for the worst and 99% of the time it will be over built but the 1% when some thing does happen and you find your bus at a place and a time of year you did not plan for your trip will not be ruined. It works for Me but only better. Brian 4905 Klamath Falls Oregon | ||
| R.C.Bishop
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We did exactly as Johnny said he would do....thought long and hard on a FF post a few years back and am glad we have done it that way. Used a marine style head..pump up and over wheel well into a large black tank under the kitchen counter. Do the same for shower water. Lav is also connected to the black...or if necessary, the grey water tank, also located under the counter. Lots of drawer space, losts of shelf space still there. Tanks total 105 gallons, IIRC. Vent properly (2") and no one will know it is there....not even the neighbors.. Fresh water is under bed, a small 7 gallon tank that feeds the marine head, and an automatic feed to that tank as it empties. Also have 11 gallons in the Hot Water heater, also marine stye with heat exchanger. Always have hot water, either by running the coach, the Webasto, or, in emergency, electricity. Thanx. works for me, too, FF. What a great board!!! Thanx, IAN!!! RCB '64 Crown Supercoach (HWC) | ||
| John that newguy Rating: N/A |
If you've never experienced a leak in a water tank or it's attached fittings, you don't know what you're missing........ With the black/gray tanks inside.. you will most definitely -not- miss a thing when the inevitable does happen. | ||
| Jim (Jim_in_california)
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EEK! Not to mention EWWWWW! OK, scratch THAT idea . Blea. | ||
| James Maxwell (Jmaxwell)
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Let's see here, in a matter of a few days we have gone from using an ac motor to run the A/C in the bus to sh-- on the floor. No damn wonder none of us ever finish these damn things. Wonder if this has anything to do with AAADD (Age Acquired Attention Deficit Disorder). | ||
| John that newguy Rating: N/A |
Wonder if "what" has anything to do with AAADD, Jim? | ||
| Jim (Jim_in_california)
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No, all these concepts are tied together: AC to insulation to freeze protection to crap on the floor. Seriously. A lot of the potential issues are "integrated" such that if you screw one area up, you get weird effects elsewhere. I've learned a LOT from this thread, much thanks to all here. | ||
| Doug Dickinson (Dougd470)
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My way - (I am still building) My coach will have the tanks in the 3rd bay for a couple of reasons. The bay is/will be insulated with 1" foam and covered with plywood and the doors will have an insulative covering inside also. The tanks will sit on a waterbed heater that will keep them and the contents up to around 50 degrees. This will, in turn, keep the compartment up in temp also. All my water will be in this compartment as well as the pumps (2) and water heater and distribution manifold. I am "pre-plumbing" for a webasto style heating system some time down the road. This will allow me to use the engine heat while traveling to heat the interior until I invest in the webasto unit. There will be a loop in the 3rd bay to keep stuff above freezing. I don't plan to use the coach for winter camping, but I will use it for traveling in the winter some times. Having the webasto will allow me to use it in the winter as emergency shelter or if I change my mind. Having the electric and webasto available will let me choose the best way to keep the coach above freezing (I don't like flames in unattended RVs - it just bothers me). I had thought about using interior space, but I am going to need every cubic inch of space to keep the wife happy. We want to full-time for a year or two when we retire (10 years or so), and that is going to require some space to keep all the "necessities" around. I will be storing the unit in a heated building so that is not an issue for me. My way Doug St Louis MC9 | ||
| Richard Bowyer (Drivingmisslazy)
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Doug, sounds like a great plan to me. Like you plan to do, DML had all tanks, pumps, water heater and anything concerning water either in the one compartment or above the floor in the coach. I had one Webasto heater, just a finned one foot section of 3/4 inch line, in the compartment which did a great job of keeping the compartment from freezing. I also had a 120 volt, 500 watt heater on a thermostat that I could turn on and also as an emergency backup, a 50 watt light bulb on a manual switch. Never had any trouble with freezing even when boondocking in below freezing areas for days at a time. Generally had to run the genset every few days to keep the batteries up for operating the Webasto. Richard |
