| Author |
Message |
Steve (Steve)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 10:05 am: | |
Im at the point of tring to figure out if I should install roof air or central air and where to get central air information? I know some of the high end buses run central air. I would like to study all ideas before I decide what to do. Any ideas? Steve |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 11:41 am: | |
Steve, It's a matter of preference.
I first note that the height of the roof tops are getting progressively less.
Practically, overall height resulting from a roof raise factors into your choice cuz of interference problems with trees and bridges.
Esthetically, some don't like all the "clutter" on the roof, preferring the original bus lines.
Also, the roof top units, unless installed above a "false" ceiling, dump alot of noise into the living spaces along with their cooling air.
Back to practical, basement units take up alot of space for ducting ect. because you have to "pump" more cool air than hot because of the temperature differential in the supply from the heater as opposed to the cooler. Bringing 90 deg air down to 78 deg with 50 deg air is harder than brining 38 degree air up to 65-70 with 130 deg. air. (#'s for example only, I didn't check first!)
Personally, I like a cleaner roof and am willing to put extra effort into constructing the ducts so I'm going with a basement installation. This choice is easier due to my decision to completely remove the Bus Air from my MCI-9
I speculate about the roof tops, worried about small units worked at top efficiency, won't last as long (just guessin')
My setup would be a standard install for any air conditioning technician. I don't know about the roof top units due to the increasing emphasis on compact sizing.
Ya makes your choice and pays your price, noise or basement space!
Onward and Upward
Marc Bourget |
RJ Long (Rjlong)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 11:56 am: | |
Steve -
Another option is one of the split system units. These have the compressor and condensor downstairs, and then an evaporator unit upstairs. No ducting of air flow needed, just run the "freon" lines.
Here's a link to an example:
http://www.cruisair.com/remotesys.html
HTH,
RJ
PD4106-2784
Fresno CA |
Jim Ashworth (Jimnh)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 3:52 pm: | |
As I have said many times before, so I ask forgivness from the "old timers", you can't store stuff on the roof as easily as in a bay. Why take up bay space when rooftop a/c's can use the roof space.
They are enormously cheaper and they are more reliable than split system units. I installed rooftops in 1991 and they are still going today without a bit of trouble. Yes, rooftops are a little more noisy but Dometic rooftops have an automatic fan which slows the closer to the set temp you get. And shuts down when the temp is reached so the noise isn't that bad except at startup.
If you go with rooftops, use 3 for a 40' coach. You'll appreciate the rapid cool and the rapid decrease in fan speed.
Just another point of view. (Which is shared by most of the major converters since they are increasingly going back to roof airs.)
Jim |
Jack Gregg (Jackinkc)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 4:36 pm: | |
Rather than repair (and convert to R-32) the split system that came with my coach, I installed three penguin roof airs at about $550 each. If they ever need repairs, I will pop them out and leave them at the repair shop.
The roof airs do have a little more noise. The remedy is to duct them.
Jack |
Marc Schlabach
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 5:18 pm: | |
I agree with Jim. You always need more bay space. I have 3 dometic units on my mc9 and I am very happy with them. If you use the ones that change fan speed and then shut off after reaching the desired temp , they are not noisy at all. Just my opinion. Marc |
Chuck Lott (Chuckmc8)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 5:42 pm: | |
I'm using 2 Duotherm roof units. I controll these with a 24volt transformer, relay and a home type wall mounted digital thermostat.
It works soooo much better than the factory "knobs" controlls. I can set the unit at whatever temp I desire, and it cycles on and off just as my home central a/c system does.
Another added benefit is that I can choose fan speed at the a/c. I usually leave the fan on Low, it's much quiter and the longer run time helps remove the humidity in the coach. If I need the added fan speed, I just switch the knob.
Its Kooollllll...... |
can't post my name
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 7:41 pm: | |
I have 3 coleman low profile rooftops which are ducted in a 3.5" ceiling on my Eagle 10 (7" roof raise) Overall height to top of AC's is 12'6"
The noise is not a problem and the ducting was not that difficult. There's probably the same amount of work ducting above a ceiling as there would be ducting from the bay, or splitting the system.
I chose rooftops because:
1. needed more bay space
2. cheap to replace if needed
Just my preference. Your's may vary.
Posting note:
I tried to enter my user name as I have in the past, but it wouldn't let me, so I had to use something off the wall.
David Anderson |
WA David (Wacoastmci)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 8:24 pm: | |
We have the system RJ Long described as a "split system" in our 102D and it is great. 3 compressors are tucked away behind front bumper area and in engine compartment so do not use any main bay space. Temp controls use auto-variable speed fans and will maintain the set temp to within a degree. We almost never need to run all three and have been cool and comfy at 100+ degrees. Provides heat also down to around 45 degrees OAT. I sure am happy with this setup. |
R.C.Bishop
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 8:38 pm: | |
For three years we debated roof tops/splits/basement and just this summer decided to go for a Coleman basement unit (ronthebusnut.com)
Installation took up an entire bay, but that was no problem since, if we had elected to put the generator in it , it would have pretty much done the same thing, leaving the A/C for another area. In our case, the trade off was just a matter of choice of convenience for working on generator.
Plenum goes straight up, behind the fridge and then is joined to a three inch duct along the transition area twixt side and roof. The ducting runs from mid-ships in both directions to front and rear. We have six good size outlets in line, plus a large one over the fridge. We exceeded all manufacturers minimum requirements for sizing of exit duct and outlets.
The unit is 22,000 BTU with two compressors. If only one unit is needed, the other remains off. Two 120 volt circuits feed the elec. box in the unit. Each compressor runs off one of the sides. Thermostat controlled. Very quiet and lots of cool air coming out.
Used the unit on a recent trip to Nova Scotia from New Mexico and was not in extreme heat so can't comment on how it preforms in that situation. All use was off the generator which, was not running up to snuff a lot of the time. ( Changed plugs and it made a world of difference)
Jury still out on how great a decision we made. Maybe next year will have a better idea. No complaints, just don't have enough information to formulate an opinion.
HTH
RCB
'64 Crown Supercoach |
Lin
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, October 18, 2004 - 9:47 pm: | |
We have two rooftops. I like them for their practicality, but they are noisy. I think that I am a bit more sensitive to that than most people. I don't think that it is the compressor that bothers me, but rather the high air velocity. Recently we were traveling out of the country and all the hotels we stayed at had split units that had very low air velocity. I guess they must have been putting out very cold air. I thought they were great and would look into it if I were starting over. However, I would probably end up with the variable speed fan rooftops and a ceiling duct. I just may add the duct to my present set up. |
FAST FRED
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 19, 2004 - 5:15 am: | |
In terms of newer tech rooftops have the advantage , as you can choose the amperage requirements to suit the campsites .
Folks that frequent the older pretty places usually have less juice at the Power Pole , and can accomodate that fact.
Since there built as toss aways the tech changes with each delivery of the parts to be assembled.
We chose basement ,as I think the camper looks better with out the row of carbunkles on the roof.
Second , the noise overhead is not acceptable during quiet times . eating , radio listening ...
Third the overhead blast of air is quick at cooling a hot coach , but thats only once a day , being IN the air cond enviroment should be pleasant.
As always , many choices ,many different requirements, many different Opinions.
Basement works the most invisibly , inside & outside , works for me.
FAST FRED |
vern rainville
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 19, 2004 - 7:04 am: | |
The above reasons for choosing roof tops vs basement vs splits all have some pro's ans some cons. I too choose the roof tops for yet another reason. As David and Jack state, if there is a problem, pop it out and repair or replace it, rather inexpensively. My thought for roof top is, if there is a problem with my roof top "system", I have the other roof tops to continue cooling. I am not so sure that is possible with the basement or split systems. Just another point of view. Vern (in RI) |
Doug Potter (Doug86newell)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 19, 2004 - 9:05 am: | |
Even with Basement airs, you need more than one. I have 3 in my coach. Two will keep the coach cool even in triple digets, but the third is necessary to get it cool. Especially in high humidity. Just one more opinion.
Doug |
Marc Bourget
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 19, 2004 - 10:18 am: | |
One thing that would be very relevant and instructional is to use the HVAC Calculator that was recently on the BB.
For instance, Doug's installation may need the 3d to "get it cool". I believe this is the first reference I've heard to a 3d basement unit (usually larger capacity than roof tops, IIRC)
So, paint color, insulation and supportive calcs would give us an actual "yardstick" rather than an exchange of opinion (not faulting ANYONE'S opinion, just seeking facts and data to enable an informed decision!)
Onward and Upward
Marc Bourget |
Jim-Bob
Rating: N/A
Votes: 0 (Vote!) | | Posted on Tuesday, October 19, 2004 - 11:01 am: | |
We have two 15,000 BTU roof air units. They are adequate in the Summer in Florida/Ga to cool our 35" bus when parked but not on the road . The front/driver's area is always warm when moving during the day especially heading into the sun. The two roof airs would be fine if we added an automotive type front dash air for driving.
We will use split units like the Cruiseair in our next bus (under construction). Super quiet, inside & outside units can be installed almost anywhere that works, utilizing odd spaces. There are millions of split systems in homes & business, selected for the same reasons.
Personally, I will not select units that vary fan speed, etc or that use digital controls & remotes, etc. The old, analog switch/knob/relay type controls are many many times more reliable & tough. They are way less sensitive to voltage & frequency fluctuations (very important with a genset). For instance, during hurricane Frances this summer, we had power fluctuations from 60 to 200 volts on our 120 volt circuits at home due to a broken neutral wire at the pole. We lost EVERY 120 volt device that had a circuit board, but NONE of the analog controled items! This is a very extreme circumstance, but it illustrates the point clearly. PC boards are fragile! Think about campground brownouts & genset malfunctions, etc.
Jim-Bob |
Steve (Steve)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Wednesday, October 20, 2004 - 10:03 am: | |
Thanks to all for the Info on Roof Air or Central Air. We are going with 3 15000btu roof tops with heat strips to cool our MC9. The factory air works great but the people that owned the bus went to Mexico often and they had the air service work done there. I guess it is cheaper and the freon is available there. Also,
What weight of oil should I run in the 1993 6V92
Engine 15w-40 or the 40 weight. When we purchased the bus 2 months ago they changed it and put in 10w-30 weight. Some people have told me to run straight 40 weight. I put 15w-40w in my big truck N14 525hp cummins. Can some one with a 6V92 tell me what weight and how many gallons it holds? Steve |
Tom Caffrey (Pvcces)
Rating: N/A
Votes: 0 (Vote!) | | Posted on Monday, November 01, 2004 - 3:55 pm: | |
Steve, if you are in a moderate climate, then the correct oil in a Delo is 40 weight, about 7 gallons. There are a number of possibilities that will qualify, but the main points are 40 weight single viscosity, CF2 rated, with no more than 1% sulfated ash content.
Multiweight oils are attractive now because of ready availability and lower cost, but the oil molecules themselves are reportedly weaker in the multiweights.
Shearing of the oil molecule is more of a problem in these port fed engines, and will lead to gummed up upper piston areas, according to various reports that I have seen.
Our own experience is that oil consumption is very low when the right oil is used. A seach in topics on this board will give you lots to look at.
For what it's worth.
Tom Caffrey PD4106-2576
Suncatcher |
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