My project is to install a mini-split with two heads. My present design is to run the 220v ac units using a transformer that has 120 vac in. These unit are a ceiling cassette units that I will mount in the ceiling where the escape hatches were/are.
I have taken the first step and purchased a Daikin system with an 18,000 btu outside unit, a 9000 btu cassette for the bedroom and a 12,000 btu cassette for the front of my bus. I decided on the Daikin brand because: You can get parts to repair, it has county wide support and my technical support source and friend recommended Daikin. Daikin is widely available and sold in many areas by United Refrigeration (UR).
So far I have opened one cassette and I am studying the manual. I need to design a mount and a weatherproof box to fit over the cassettes.
I promise pictures in my future post.
Art
Very interested to see how these work out for you. I was planning on running the same way, except I want to run mine from a inverter on the house batteries.
Yes, I have only heard good things about Daikin. My plan (since I have "two zones") has been to run two separate units on 120v but the thinking about the 240V dual head arrangment has had me thinking. To be able to run the two head units (although they'd be near each other) on a single compressor would sure save installation volume, plus I'd only have to deal with one set of ducting for fresh air into and hot air out of the condenser.
I'm up to my elbows in alligators with my engine change so I won't be ready to move for a few months but I'm very interested in your experience too, Art. I was down at the Cape Lookout 50th Anniversary event last weekend -- made me remember how nice "Down East" is and how I should visit more often; when you know more, maybe I could drop by and have a look at your installation.
In a big FWIW, I recently got inspected and asked where my mandatory escape hatch was. I said the stock bus escape hatch is fully functional as are the windows that aren't covered by walls. Which led me to ask myself if that was a serious question that I had better answer right, or a random question that was just off the cuff. Therefore I discovered that it appears that escape hatches are mandatory in RV's. Just a thought as you re-use your escape hatches for AC mounts. I think most RV have one big window that is an escape hatch, for sure I never saw a roof hatch on one (not that they don't exist, I'm sure).
Brian the only factory built rv I have ever seen with a roof escape was a cabover truck camper. Just an oversized roof vent basically.
I have opened the cassette and it appears well built. I have come up with an mounting plate design to go on the roof with hole in the middle for the cassette to extend through and to support the cassette. This plate will be sealed to the roof and made water proof. I'm going to have a one inch square welded all the way around the outside edge of the plate. This will provide enough thickness that I can drill and tap for bolts to seal the cover to the plate. I expect the aluminum plate and bar to arrive tomorrow. Once I have the plates cut and welded I will look for someone to make aluminum covers. Pictures to come.
Quote from: ArtGill on June 28, 2016, 06:20:40 PM
I have opened the cassette and it appears well built. I have come up with an mounting plate design to go on the roof with hole in the middle for the cassette to extend through and to support the cassette. This plate will be sealed to the roof and made water proof. I'm going to have a one inch square welded all the way around the outside edge of the plate. This will provide enough thickness that I can drill and tap for bolts to seal the cover to the plate. I expect the aluminum plate and bar to arrive tomorrow. Once I have the plates cut and welded I will look for someone to make aluminum covers. Pictures to come.
Make sure tou have enough wall on the evap condensation collection pan for the water. These things put out gallons of water. Best to have a drain on both sides of the pan and make sure your drain runs pretty straight downhill.
That was the most overlooked part of my installation when I did it. We would go around corners and Id get a good bit of water dripping on my head. I even remounted the inside unit at a steeper angle to help with the runoff and still would have water flowing out of the pan.
-Sean
Sean what do you think one needs a 2" deep or another idea if ya can, I had an interest in these awhile.
Floyd
The Daikin cassette has a condensate pump built in, but I will check the depth of the pan.
I waiting on the shop to cut and weld my base plate out of 1/4 Aluminum. What are some suggestions to mount this plate to my roof. It needs to leak proof for going down the road and hold the unit on. My roof appears to be stainless or aluminum with a little sagging between ribs and it is painted. On the coast we use 3M 5200 for everything, but is there something better that doesn't require screws? Has anyone heard of a two part epoxy call "metal Epoxy"?
Art
If this area inside is free from ceiling then the options are a few more, I think better just because drilling for bolts or rivets for the mounting.
On your base plate setup, with more of your description or pics I might consider it the permanent hd mount being riveted with a bead of 5200 on the outer edge, but have studs on the very top so mounting the condenser however can be mounted as you require.
Again not sure the picture in my head is the right show !, same channel though ;)
good day
Floyd
The unit is designed to fit in a 2 x 2 grid type hanging ceiling. The unit is designed to be supported from the rafters that the ceiling is hung from. My present plan is to put adjustable feet where the supports from the rafter would go and nut on both sides of the bracket on the side of the unit. The 1 x 1 aluminum bar that will be welded around the edge of the plate is provide for drilling and taping holes for threaded studs. The purpose of these studs is to hold down the weatherproof cover over the unit.
So, my question is there some way to "glue" this plate to the roof without putting holes in the roof. My concern is about leaks that I will not find until after the interior is completed.
Thanks, Art
I am not visualizing what you are doing exactly, but when it comes to putting something on the roof I would not rely on just one method of adhesive. A combination of solid connectors and adhesive might be safer. The sun is going to bake your roof, and will whatever adhesive you use last indefinitely?
Ok I have a lot better idea of the project now, but I cannot at the moment name a product.
You and I both know so many car, truck and trailer type body's use some adhesives and have for many years.
I know we have mentioned a few names of stuff here but knowing well there are many companies that make this type stuff for the manufactures.
Its possible a tech call to a couple adhesive mfg's. and what I can recall with a few searches way back is that many super adhesives were using a heat applied system or a 2 part in the factory setting videos.
These companies also had listed other part numbers so with a bit more looking its sure possible to find something, I will keep an eye out for something.
It may still be recommended to have a mechanical fastener of some rating, you know how that goes, not many engineers signing off there.
One would have to just consider that auto bodys have to have a tac weld or other fastener, yet the fiberglass hoods I have dealt with are completely glued as I seen. go figure!
hey thanks for the better picture of the project, good luck
Floyd
I've been trying to understand what you are doing. MCI roof is 2" thick. Do you have a dropped ceiling/raised roof situation? Or are you planning to build roof top boxes and stick the cassette up through the roof and stick out the top. If the latter, I would tig weld up a box of .100" aluminium with a flange all around it, curved to fit the roof top perfectly, and use double-sided tape and blind rivets to hold the box to the roof, and mount the cassette inside that. You can get blind rivets that are leak-proof with a solid end. If I was to do this I would guarantee that it would not leak. The construction method is very similar to how they build tractor trailers these days.
Yes, the cassette will extend above the roof. My plan is to construct a box with a lip. The base plate that I want to install on the roof water tight. The base plate will have edge of 1 x 1 inch square rod that is welded on to make it ridged. At the width of the base plate my roof only has 1/8 of inch roll off on each side that I hope to fill with some adhesive. I plan to attach the box to the base using bolts or studs, a rubber gasket, and that allows the box to be removed for maintenance.
(http://baseplate.gif)
This is a picture posting test
file:///C:/Users/Owner/Pictures/2016-07-10/Base%20plate.gif
Picture test
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Ffile%3A%2F%2F%2FC%3A%2FUsers%2FOwner%2FPictures%2F2016-07-10%2FBase%2520plate.gif&hash=fc59499445e038230e24cfc75c0ee83f22edb6b9)
another picture test
I give up trying to post pictures, for tonight.
Just so we are still on the same wave length here. You are going to cover up and delete not one but both roof escape hatches to install your A/C? Will both roof escape hatches still be usable as vehicle escape routes? Respectfully.
Quote from: ArtGill on July 10, 2016, 07:02:43 PM
file:///C:/Users/Owner/Pictures/2016-07-10/Base%20plate.gif
Picture test
you have to upload your pictures on the internet...like photobucket.com (http://photobucket.com) first...you can't upload directly from your computer user file to this site...
Possibly resizing them so when your mouse is over them and if they show to be less than 128 kb, this usually loads ok and just makes another at the smaller size in your files.
Its a trial doing it as figuring out if 180 x 240 is going to be small enough, so this is leading to joining one of the photo sites and learning their ops.
Floyd
I still get flustered posting pictures here. I go to BGM and post and direct someone who needs to view to go there. I have 2 splits in house and three in bus. Very happy. Condensate has been only challenge. Bob
F/B is the place to post photos so easy there just click our Eagles board lets you post too no easy either.I am sure if we chipped in a few coins Gary and Mike could make it happen in case one hasn't noticed this board has a lot of members that could eat up hosting space.I don't if it's fact or not but I have been told you guys help pay for the BGM board is that true ?
I made a donation. Well worth it. Would be glad to do same here! Wouldn't take to many 10 or 20's to add up. There are no adds on BGM . Strictly a observation. I am a long time member of both. Thanks for the free access. Donation toward operating expenses here just say the word. Set up a pay pal and I'll chip in. Bob
I am like you Bob I gave up trying to post pictures here because I never could make it work,but I can see the point the photos eat up a lot of data on some peoples internet plan just to open.
LOL I rag on Gary every time I see him about hosting photos just because I cannot get the hang of posting photos some where else and then getting them back here.
I had to get Dave5C to help me when I put photos in a folder and couldn't retrieve the photos he made it look so easy. ??? I put some photos in cloud he couldn't even retrieve they are lost forever I guess
Quote from: ArtGill on June 24, 2016, 06:49:09 PM
My project is to install a mini-split with two heads. My present design is to run the 220v ac units using a transformer that has 120 vac in. These unit are a ceiling cassette units that I will mount in the ceiling where the escape hatches were/are.
I have taken the first step and purchased a Daikin system with an 18,000 btu outside unit, a 9000 btu cassette for the bedroom and a 12,000 btu cassette for the front of my bus. I decided on the Daikin brand because: You can get parts to repair, it has county wide support and my technical support source and friend recommended Daikin. Daikin is widely available and sold in many areas by United Refrigeration (UR).
So far I have opened one cassette and I am studying the manual. I need to design a mount and a weatherproof box to fit over the cassettes.
VERY interesting. I am also considering installing a 24KBtu+ mini-split system, albeit in my 05 42ft Monaco Dynasty coach. This is to replace the 3 aging, VERY NOISY and inefficient Dometic Penguin roof ACs. I think I have 220V available from the 10KV Onan genset but since the whole coach is only wired for 110V, I would like to run it from 110V using something like: http://tinyurl.com/hr5gd8t (http://tinyurl.com/hr5gd8t) IF practical.
I am told that the startup current on these inverter condensers is no problem for the transformers but would like to hear some actual experience BEFORE I start spending $$ on a system. Have you tested this yet?
Also, I do have a ~ 5"D x 12"W channel in the current ceiling that runs the length of the coach. It currently contains ducting, condensate drains and the wiring for the roof ACs. I'm pretty sure that with thoughtful modification, I can mount 2-3 ceiling cassette units with refrigerant lines and necessary cabling in there.
This leaves the question of where to mount the condenser unit ?? Ideas??
TBoone Fisher
Granbury, TX
I have basic questions I'm trying to understand. Is there an issue of taking 120V half-phase power and running it through a transformer to 240V? Do you get a full phase (i.e. 120V up and 120V down, on the oscilloscope)? If not, is there any problem with this?
Quote from: Oonrahnjay on July 12, 2016, 08:48:22 AM
I have basic questions I'm trying to understand. Is there an issue of taking 120V half-phase power and running it through a transformer to 240V? Do you get a full phase (i.e. 120V up and 120V down, on the oscilloscope)? If not, is there any problem with this?
The main problem as I see it is will the transformer/converter handle the startup current of the condenser. As I understand it, these inverter condensers startup much more gradually than a conventional outdoor condenser/compressor. This results in a much lower startup current spike. Am I correct?
TBoone Fisher
Granbury, TX
Quote from: tbfisher on July 12, 2016, 09:27:33 AM
The main problem as I see it is will the transformer/converter handle the startup current of the condenser. As I understand it, these inverter condensers startup much more gradually than a conventional outdoor condenser/compressor. This results in a much lower startup current spike. Am I correct?
TBoone Fisher
Granbury, TX
Yes, that's correct but it's kind of "how long is a piece of string" sort of thing. The real question will be "will the reduced startup spike be reduced enough".
start up spike. Make sure you buy inverter type. My 12,000 pulls 8 amp max @120 V. the 9,000 pull 6 amp max @120 V
There is no such thing as 120V half-phase power, but I understand what you mean. The transformer will take the 120V single phase AC in and double it to 240V single phase AC. Exactly the same, only twice as much voltage. The transformer will have a center tap, that becomes neutral and the two live legs are each 120V single phase with respect to the center tapped neutral. This is exactly what the main power transformer on the pole outside your house does (except it is usually taking something like 7KV single phase and transforming it down to 240V center tapped single phase) and the power is, for all intents and purposes, identical to house power.
Start up current is simply a matter is selecting the appropriate size transformer. If you need 20 amps at 240V to start the thing, buy a 5,000 watt transformer.
Brian
so...how many evaporator units/heads will one compressor unit run...?
Quote from: bevans6 on July 12, 2016, 11:29:43 AM
There is no such thing as 120V half-phase power, but I understand what you mean. The transformer will take the 120V single phase AC in and double it to 240V single phase AC. Exactly the same, only twice as much voltage. ...
Thanks, Brian, that's very helpful and it's getting to the heart of the lack of understanding that I have. But there is a detail I'm not clear on ad I'd appreciate a little clarification.
1) For "ordinary household current", I think that I have seen info that N. American 120V, as shown on a waveform graph, is starting at 0 voltage on the waveform, rising in the sine wave to 120V above the line and then falling back to the 0V point; then a gap of the same time (set by the Hz of the power) at 0V, after which the process repeats itself. For 240V, the waveform begins at 0V and rises to 120V then g back to 0V; from here, the waveform goes mirror-image "down" to 120V (on the "other leg") and then back up to 0V. This 240V power is a full "positive" sinewave and a complementary "negative" sinewave as a single cycle -- "positive" and "negative" meaning of course the layout on a graphic readout, not pos and neg in an electrical sense.
Am I understanding this right so far? If so, it would seem to me that an electrical load that was designed to operate on 240V single phase would want that full sine wave "up and down".
And that is the point of my lack of understanding here. If 120V is as I've described it above on a graphic readout and 240V is also as I've described it, does the 120V - 240V transformer change the waveform as well as the total voltage? Or when you say "exactly the same, only twice as much voltage", will the 240V output begin a 0V, go up to 240V and then back to 0V -- and if it does, does that matter?
Sorry for lack of understanding here but I'm just trying to figure out how the system we're talking about here would work and what that will translate to on my bus. Thanks for the help. BH
I asked once and got a bunch of answers on how to post pictures. Sosss ... I will be the fall guy and politely ask again: ...
Are you disabling BOTH of your factory roof escape hatches to install your split A/C units? Respectfully. HB :(
PS: And if sossss .... WHY?
Both 120vac and 240 vac are full wave 60 cps just the wave height for 240 is twice as high as the 120. Remember that a pure 240 vac device does not need a neutral, just two hot legs. The transformer will have hot leg and a neutral on one coil and output 240 on two wires on the other coil. The number of wraps of each coil will have a ratio of 2:1, with the 120 vac input will have the more wraps than the 240 vac output. These coils are wrapped around a steel core.
TBoone, I'm in the process of making the installation. I have checked the current draw on an actual unit and found the current draw ramped up slowly. The compressor and fan speeds are variable and therefore the current draw is variable controlled by cooling demand.
I have seen up to four inside units supported by one out side.
Yes, I am using the locations of the roof escape hatches for my units, but the hatches have been long gone.
I love it when others post their project pictures and I wanted my project to be a benefit to other, but I will post how my project turns out when I finish it.
Art
Quote from: ArtGill on July 12, 2016, 07:37:31 PMBoth 120vac and 240 vac are full wave 60 cps just the wave height for 240 is twice as high as the 120. ...
Thank you, Art. I misunderstood items that I had previously read on this. This information is very helpful to me and it makes me understand how the plain transformer can work for this system.
Quote from: ArtGill on July 12, 2016, 07:37:31 PMI wanted my project to be a benefit to other,
Art
Very much so. This discussion has pretty much solved most of my air con design problems and issues.
Quote from: ArtGill on July 12, 2016, 07:37:31 PM
TBoone, I'm in the process of making the installation. I have checked the current draw on an actual unit and found the current draw ramped up slowly. The compressor and fan speeds are variable and therefore the current draw is variable controlled by cooling demand.
Thanks Art. Sounds like the 110V to 220V conversion will be no problem. Now I just need to figure out a good place for the condenser unit in my coach. I am really looking forward to having a very efficient and QUIET system since the noise level is 80dB+ in my coach with the AC running. >:( I bet that coach manufacturers and converters are seriously looking at this also.
TBoone Fisher
05 Monaco Dynasty Diamond IV
Granbury, TX
Quote from: tbfisher on July 12, 2016, 08:35:09 PM
Thanks Art. Sounds like the 110V to 220V conversion will be no problem. Now I just need to figure out a good place for the condenser unit in my coach. I am really looking forward to having a very efficient and QUIET system since the noise level is 80dB+ in my coach with the AC running. >:( I bet that coach manufacturers and converters are seriously looking at this also.
TBoone Fisher
05 Monaco Dynasty Diamond IV
Granbury, TX
Coach converters will never go that route they are not into efficiency and roof tops are coming with the inverter technology Coleman plans on marketing one next year(made in China). 21,000 BTU will keep a bus cool when parked but not on the road.I have 65000 BTU of cooling ( 5 Penguins) foam spray and double pane windows plus my dash air of 44000 BTU but I live in AZ too and I like cold air
OK, I found a diagram on a Samlex website (not that I'm impressed by their inverters, but that's another story). Is this what we're looking at?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi45.photobucket.com%2Falbums%2Ff60%2Foonrahnjay%2FBus%2FTransformer120Vto240Vsingle_zpsfazsxbvu.png&hash=9a4ac5cecbe49ea6a1ce3409dd986c269c272893) (http://s45.photobucket.com/user/oonrahnjay/media/Bus/Transformer120Vto240Vsingle_zpsfazsxbvu.png.html)
And I've been trying to visualize how the two legs of the 240V are arranged. I've slightly altered the above diagram and used a NEMA 4-pin image for clarity, although I'm going to guess that most everyone will "hardwire"; I also would guess that the 240V air con circuit will not include 120V sockets, they'd be in a separate circuit but this is just for simplicity. Is this correct?
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi45.photobucket.com%2Falbums%2Ff60%2Foonrahnjay%2FBus%2FTransformer120Vto240Vdouble_zpsi7uhi1x2.png&hash=2267b241ff335827bddbd6d10d75128cc90d7d48) (http://s45.photobucket.com/user/oonrahnjay/media/Bus/Transformer120Vto240Vdouble_zpsi7uhi1x2.png.html)
Still trying to get a good picture in my head. Thanks, BH
Electricity is fun stuff. Believe it or not, I learned this stuff in grade 11 shop class. We had a shop class just for electricity. I bet they don't now. I later took electronics in college, and worked with this stuff my whole life.
AC voltage, your typical 120VAC from the wall plug, has a hot lead and a neutral, with the neutral referenced to ground. The voltage on the hot lead starts at zero (with reference to neutral), rises to a peak voltage of 170 volts, goes back to zero, goes to minus 170 volts and back to zero, so the actual voltage swing is 340 volts and the average voltage is zero. That is one cycle, and it does it 60 times a second. Why do we call it 120VAC instead of 170 volts or the even more logical 340 volts? Because electricity grids started out with DC voltage, and the 120 VAC as we call it is the equivalent of 120 DC volts. The 120 AC volts is sometimes marked "RMS volts" on a meter, and happens to be 0.707 (the sin of 45 degrees) times the peak voltage of 170 volts (rounded off the decimal points).
240 volts is two 120 volt legs that happen to be exactly opposite added together. When the first 120v leg's waveform goes positive, the second goes negative. At 1/240th of a second they are each at their peak of 170 volts with respect to neutral, for a total of 340 volts, and at 1/120th of a second they are both at zero volts with respect to neutral, and they do that again for a complete cycle at 1/60th of a second. If you take one of the legs and call it the reference, then what you would see is a normal sine wave shape that goes from zero to 340 volts and back again, so 340V times 0.707 is our familiar 240VAC.
RMS means "the root of the mean of the squares" and if I ever actually understood the math of why the sin of 45 degrees happens to be the AC equivalent of DC power, I sure as heck don't remember now. I expect I will google it and try to remember sometime today... It involves calculus, and I don't like calculus...
Brian
Quote from: luvrbus on July 12, 2016, 09:23:21 PM
Coach converters will never go that route they are not into efficiency and roof tops are coming with the inverter technology Coleman plans on marketing one next year(made in China). 21,000 BTU will keep a bus cool when parked but not on the road.I have 65000 BTU of cooling ( 5 Penguins) foam spray and double pane windows plus my dash air of 44000 BTU but I live in AZ too and I like cold air
I can see that there wouldn't be much concern about efficiency but IMHO, noise is a bigger issue. I doubt that they could ever make a roof top unit that is as quiet as a mini-split cassette would be. I have a neighbor who has a very nice mult-islide Newell. I was sitting in it for the first time when the AC came on. Without me saying anything about the obvious noise level, he promptly commented that the AC was very noisy. I think he said it had 4 Coleman units. IF I paid that much for a coach and it were that noisy inside, I would be VERY pissed off to say the least. >:(
TBoone Fisher
Granbury, TX
Quote from: tbfisher on July 13, 2016, 07:27:49 AM
I can see that there wouldn't be much concern about efficiency but IMHO, noise is a bigger issue. I doubt that they could ever make a roof top unit that is as quiet as a mini-split cassette would be. I have a neighbor who has a very nice mult-islide Newell. I was sitting in it for the first time when the AC came on. Without me saying anything about the obvious noise level, he promptly commented that the AC was very noisy. I think he said it had 4 Coleman units. IF I paid that much for a coach and it were that noisy inside, I would be VERY pissed off to say the least. >:(
TBoone Fisher
Granbury, TX
Yep but those 4 roof tops on a Newell have a total of 60,000 BTU cooling not 20,000 BTU and all are 110v no assembly required
Quote from: luvrbus on July 13, 2016, 08:08:19 AM
Yep but those 4 roof tops on a Newell have a total of 60,000 BTU cooling not 20,000 BTU and all are 110v no assembly required
Do you think that since they are sitting in direct sun, ducted through a very inefficient system and subject to all the abuse that roof ACs take that they are actually delivering 60K BTU ?? Also what effect do you think that driving them down the road in a 60++mph typical AZ or TX hot air blast might have on them?
I doubt that roof ACs ever get close to
effectively delivering their rated output;-)
TBoone
Granbury, TX
I'm looking at these for a positive, and heres actually an old reason take a look see for yourselves when ya have to look at the news on the tv again.
These other countries I see many but not all have a lacking electrical infrastructure compared to ours. When I see the housing, apartment flats and other buildings in the screen shot that's panning, Its pretty clear they have these type systems it looks like to me. So as a basic they must have a decent service factor as most of the screen shots are desert and tropical, with marginal electric. I think with that they could be tough enough. Now that I'm looking at these some more and could use some laymen information in there use going down the road with required venting, protection, drafting issues, Just some things I might consider planning toward.
Thanks for the topic and
good day
Floyd
Quote from: eagle19952 on July 12, 2016, 12:36:32 PM
so...how many evaporator units/heads will one compressor unit run...?
I must still be on the ignore list...
or my question is to stupid.
??? >:( ???
Quote from: eagle19952 on July 13, 2016, 11:17:26 AM
I must still be on the ignore list...
or my question is to stupid.
??? >:( ???
Not stupid BUT the answer is readily available here:
https://www.google.com (https://www.google.com)
Have a look at the following. It should give you a good idea:
http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf (http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf)
Tboone
Granbury, TX(HOT)
Quote from: tbfisher on July 13, 2016, 12:44:31 PM
Not stupid BUT the answer is readily available here:
https://www.google.com (https://www.google.com)
Have a look at the following. It should give you a good idea:
http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf (http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf)
Tboone
Granbury, TX(HOT)
Google is great if you know what you are looking for.
the link explains it.
the base compressor unit with the most capacity can run 3 zones with up to 8 evaporators, apparently limited to 4T. or the equivalent of 4 average roof units.
prettty simple answer.
thanks.
Sounds good but if something happens to the condenser with 1 compressor you are dead in the water.AC units never quit unless you are using it, no redundancy that why the big boys stay with roof tops or 2 basement airs, 5 roof tops on a 2 mil coach are common and will be for a long time IMO
Quote from: tbfisher on July 13, 2016, 12:44:31 PM
Not stupid BUT the answer is readily available here:
https://www.google.com (https://www.google.com)
Have a look at the following. It should give you a good idea:
http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf (http://www.fujitsugeneral.com/pdf_06/halcyon06_brochure.pdf)
Tboone
Granbury, TX(HOT)
thanks for pointing that out.
Quote from: luvrbus on July 13, 2016, 03:58:48 PM
Sounds good but if something happens to the condenser with 1 compressor you are dead in the water.AC units never quit unless you are using it, no redundancy that why the big boys stay with roof tops or 2 basement airs, 5 roof tops on a 2 mil coach are common and will be for a long time IMO
I would think that since mini-splits are mainstream and made by all the major manufacturers, it might be easier/faster to R&R them than a rooftop unit. If you are worried about a failure, rather than having a built-in redundant condenser, you could carry around a portable 12KBTU unit....OR just stop by any Lowes/HD/Walmart/Etc. and pick one up to use until you can get your system fixed. Ideas?
TBoone
Granbury, TX (102F with 2 NOISY roof airs running)
LOL 102F golfing weather for Az it's 113F here ??? but it is a dry heat like a hair dryer with the breeze,headed for Idaho where I may need heat in the mornings.I really believe the mini splits would be fine if parked all the time but we move and very seldom are connected to a pole.The AZ heat will give a generator and AC units a work out for sure
Quote from: luvrbus on July 13, 2016, 03:58:48 PM
Sounds good but if something happens to the condenser with 1 compressor you are dead in the water.AC units never quit unless you are using it, no redundancy that why the big boys stay with roof tops or 2 basement airs, 5 roof tops on a 2 mil coach are common and will be for a long time IMO
Having a plan B for cooling is very wise, you can not depend on just one unit to be infallible. I have a 3 ton central air that works great, but I will also add roof airs as backup, and for campgrounds that do not have 50 Amp hookups. Roof airs can be taken off and changed in not much time, and it might cost less than servicing a big unit. Do what the big boys and NASA does; have backups.
3T basement here too.
if it got real rough a week in a hotel would be a vacation. so that $500.00 would be well spent waiting on repairs.
my unit by FirstCO out of Dallas TX has been in service since 1990.
since 2004 i have replaced the compressor in 2011 and the condenser fan motor in 2008 because they died and the A coil in 2013 because the condensate pan rusted out.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fs1207.photobucket.com%2Fuser%2Fdphalaska%2Fmedia%2FImage022-1.jpg.html&hash=7a81ae9f58098d4f2b701355118f50e0960d3206)
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2FImage022-1.jpg&hash=f54155314a36d8f8398f1c572ccc1607382a8025)
Quote from: eagle19952 on July 13, 2016, 09:43:25 PM3T basement here too.
if it got real rough a week in a hotel would be a vacation. so that $500.00 would be well spent waiting on repairs.
my unit by FirstCO out of Dallas TX has been in service since 1990.
since 2004 i have replaced the compressor in 2011 and the condenser fan motor in 2008 because they died and the A coil in 2013 because the condensate pan rusted out.
That's really good service, Don. What brand is it? Is it an RV model or a household/commercial unit? Any idea of the current draw and is it 120V? Are parts available OK? Do you have ducts to distribute the cool air?
Thanks, BH
Quote from: DoubleEagle on July 13, 2016, 07:27:38 PM
Having a plan B for cooling is very wise, you can not depend on just one unit to be infallible. I have a 3 ton central air that works great, but I will also add roof airs as backup, and for campgrounds that do not have 50 Amp hookups. Roof airs can be taken off and changed in not much time, and it might cost less than servicing a big unit. Do what the big boys and NASA does; have backups.
Several possible plans B:
http://www.homedepot.com/b/Heating-Venting-Cooling-Air-Conditioners-Coolers-Air-Conditioners-Portable-Air-Conditioners/N-5yc1vZc4m4 (http://www.homedepot.com/b/Heating-Venting-Cooling-Air-Conditioners-Coolers-Air-Conditioners-Portable-Air-Conditioners/N-5yc1vZc4m4)
http://www.walmart.com/browse/home-improvement/portable-air-conditioners/1072864_133032_133026_587564 (http://www.walmart.com/browse/home-improvement/portable-air-conditioners/1072864_133032_133026_587564)
http://www.lowes.com/search?searchTerm=portable+air+conditioners (http://www.lowes.com/search?searchTerm=portable+air+conditioners)
Etc..
IMHO, better than lugging around roof ACs that would rarely be used :)
TBoone
Quote from: tbfisher on July 14, 2016, 06:12:37 AM
Several possible plans B:
http://www.homedepot.com/b/Heating-Venting-Cooling-Air-Conditioners-Coolers-Air-Conditioners-Portable-Air-Conditioners/N-5yc1vZc4m4 (http://www.homedepot.com/b/Heating-Venting-Cooling-Air-Conditioners-Coolers-Air-Conditioners-Portable-Air-Conditioners/N-5yc1vZc4m4)
http://www.walmart.com/browse/home-improvement/portable-air-conditioners/1072864_133032_133026_587564 (http://www.walmart.com/browse/home-improvement/portable-air-conditioners/1072864_133032_133026_587564)
http://www.lowes.com/search?searchTerm=portable+air+conditioners (http://www.lowes.com/search?searchTerm=portable+air+conditioners)
Etc..
IMHO, better than lugging around roof ACs that would rarely be used :)
And a possible plan A:
https://www.ajmadison.com/cgi-bin/ajmadison/LG36KB38.html (https://www.ajmadison.com/cgi-bin/ajmadison/LG36KB38.html)
Quote from: Oonrahnjay on July 14, 2016, 05:26:41 AM
That's really good service, Don. What brand is it? Is it an RV model or a household/commercial unit? Any idea of the current draw and is it 120V? Are parts available OK? Do you have ducts to distribute the cool air?
Thanks, BH
the brand is http://www.firstco.com/ (http://www.firstco.com/)
220v. is what makes it durable but not popular.
and the newer units have bladed fans vs. squirrel cage hence a different installation dimension.
mine is an all electric coach 12kw (maybe 15kw) with electric heat.
ps it was desighned for commercial use on multi storry condo's
the air handler is vertical in a closet in the coach, it is 20"x20"x30" approx. and the roof wall curve is integrated into/as the duct. it runs behind cabinets..
Quote from: tbfisher on July 14, 2016, 06:12:37 AM
better than lugging around roof ACs that would rarely be used :)
I have considered the many portable units that are out there for the bus and my cabin cruiser, but one problem is the floor space they take up, and the problem of spreading the air around from one discharge point. The bigger units are about the same price as the roof-tops. The smallest portable units have a square footage of 1.75 - 2.0. They do have the advantage of being more portable than a roof-top by a good margin. If someone has the space for them, they might work well. Some of them even have heat strips. I have three spare roof-tops, but they stay on the shelf in the garage until they are needed.
Quote from: eagle19952 on July 14, 2016, 12:16:07 PM
the brand is http://www.firstco.com/ (http://www.firstco.com/)
220v. is what makes it durable but not popular.
and the newer units have bladed fans vs. squirrel cage hence a different installation dimension.
mine is an all electric coach 12kw (maybe 15kw) with electric heat.
ps it was desighned for commercial use on multi storry condo's
the air handler is vertical in a closet in the coach, it is 20"x20"x30" approx. and the roof wall curve is integrated into/as the duct. it runs behind cabinets..
Interesting. I'm pretty sure that I can fit three cassettes in my existing ceiling channel. For me, the question will be where to put the condenser making sure that it has adequate air flow. I would prefer to put behind the tag on the passenger side of the coach. Currently, there is a house battery box there which might be moved and replaced with AGMs which would allow more flexible battery placement.
I think that part of the topic here is a great discussion, and I would be interested in a bit more info.
Heck if one can and has room on top or even in the spare tire area if that's an option, no doubt a concern of mine for its placement.
Floyd
Quote from: DoubleEagle on July 14, 2016, 01:36:30 PM... If someone has the space for them, they might work well. ...
Not in my experience. The missing and missed Sean W. once pointed out that they pull their condenser air from inside the room. So basically, what they do is cool some air and then run it through the condenser and dump it overboard. I have a small-medium unit I use in a very small bedroom and in NC heat and humidity, it can hardly keep up.
The instructions clearly show the area that's the intake for the condenser so I've been thinking about adding a reverse-nozzle with a hose that will draw condenser air from the outside.. But I kinda got my hands full with other stuff right now. BH
Quote from: Oonrahnjay on July 14, 2016, 07:14:33 PM
Not in my experience. The missing and missed Sean W. once pointed out that they pull their condenser air from inside the room. So basically, what they do is cool some air and then run it through the condenser and dump it overboard. I have a small-medium unit I use in a very small bedroom and in NC heat and humidity, it can hardly keep up.
The instructions clearly show the area that's the intake for the condenser so I've been thinking about adding a reverse-nozzle with a hose that will draw condenser air from the outside.. But I kinda got my hands full with other stuff right now. BH
That is good to know. It looks like their BTU ratings might not be as effective as the numbers imply. Roof-tops remain more practical at this point. It would seem that the engineers who developed them would have taken the condenser air source into account.
Quote from: DoubleEagle on July 14, 2016, 07:36:38 PMThat is good to know. It looks like their BTU ratings might not be as effective as the numbers imply. Roof-tops remain more practical at this point. It would seem that the engineers who developed them would have taken the condenser air source into account.
"Make it cheaper .." It's the curse of trying to buy anything that works well. As I said, when I get that tuit, I'm going to try to rig up and outside air feed for the intake for the condenser air. As it is now, my unit's most important product is noise, followed by cool air. It is better than nothing, I guess, but I just can't say that it's very good.
I have 3 mini-split in bus. One condenser in spare tire compartment intake thru front bumper area exit thru compartment floor to rear. One in old evap bay for orig over road air and one in condenser bay again orig over road air. both intake thru floor and exit thru side. Inverter type total elect draw 20 amp @ 120 volt Max. They put out allot of water--so plan ahead for getting it drained outside bus. 1 ea 12,000 above driver one 9000 mid ship and 9,000 in bed room. 3 is a overkill when parked but if one craps out the other two can run. This is for info only and has worked for me. I have a friend that has both of his condensers in one condenser bay set on angle with a box fan helping pull intake air in thru floor. Ben doing a fine job for 10yrs.This is much harder that the plug and play roof tops. sort of outside box.
Most of the guys here that have done it will not speak up because of chance of misleading some one. you must pay attention to details. I use them as my primary heat source also.
Quote from: robertglines1 on July 16, 2016, 06:56:31 AM
I have 3 mini-split in bus. One condenser in spare tire compartment intake thru front bumper area exit thru compartment floor to rear. One in old evap bay for orig over road air and one in condenser bay again orig over road air. both intake thru floor and exit thru side. Inverter type total elect draw 20 amp @ 120 volt Max. They put out allot of water--so plan ahead for getting it drained outside bus. 1 ea 12,000 above driver one 9000 mid ship and 9,000 in bed room. 3 is a overkill when parked but if one craps out the other two can run. This is for info only and has worked for me. I have a friend that has both of his condensers in one condenser bay set on angle with a box fan helping pull intake air in thru floor. Ben doing a fine job for 10yrs.This is much harder that the plug and play roof tops. sort of outside box.
Thx for the info and ideas. Since I don't have the basement storage area in my 42ft Monaco that one has in a typical bus conversion, I
think I need to limit my system to one condenser and three ceiling cassettes. So far I am thinking somewhere in the rear or right rear area. This makes it easier to run the refrigerant, power and control lines up the rear of the coach into the ceiling channel which runs the length of the coach. I might even fabricate some sort of bracket to mount the condenser externally on the rear of the coach just to make sure everything works well
before I go further. This would allow me to use and evaluate the system without making any irreversible mods to the coach.
I really appreciate everyone's ideas especially since so many here have already "been there and done that" ;)
Has any mini split manufacture ever approved one for mobile or rv use yet ? I have never helped with the install of one, I have only helped on the removals those things are sorta cheap made and the boards are expensive.I still maintain they should work if parked but are not going to last driving much the copper tubing is so thin on those units
Quote from: luvrbus on July 16, 2016, 04:27:22 PM
Has any mini split manufacture ever approved one for mobile or rv use yet ? I have never helped with the install one, I have only helped on the removals those things are sorta cheap made and the boards are expensive.I still maintain they should work if parked but are not going to last driving much the copper tubing is so thin on those units
Do you think that the quality of a typical RV roof unit is any better? I bet not. My thinking is that the mini-split units are now so mainstream that parts and service will be much better and more readily available than RV roof units. IMHO, it is the same with propane RV refers. They are way overpriced and perform very poorly when compared with residential refers that are readily available all over N. America. I replaced my Norcold(aka NotSoCold) 1200($2400!!!) refer with a GE residential model($700)from HD that is far superior to the NotSoCold. It was one of the best mods that I've made to my coach so far. My gut feeling is that the mini-split mod might be the same ;)
My son in law is a HVAC contractor in Bullhead City he says all mini splits are cheaply made lol he loves them they keep his trucks and employees busy, then he does feel sorry for people that need to wait 10 days on board with temps of 110F
Quote from: luvrbus on July 16, 2016, 05:11:57 PM
My son in law is a HVAC contractor in Bullhead City he says all mini splits are cheaply made lol he loves them they keep his trucks and employees busy, then he does feel sorry for people that need to wait 10 days on board with temps of 110F
All of them? Does he have any thoughts/preferences about the best or worst?
I am considered by some to be a little slow...i now understand...stuffing most of these suggestions in a MH is virtually impossible..
i understand your dilemma. sort of...
He said he has better luck with parts from Senville he can get most parts overnight,it's not that easy with most Chinese units Carrier (made in China) is the worst for parts he told me
I went through a lot of comments on Amazon by a lot of buyers of several brands as a result of this thread. One area of complaint was that the circuit boards can fail more quickly in more humid and salty air areas, and that they were relatively expensive and slow to get. There were a lot of mystery names for brand names, which suggests Chinese origin. The inverter splits are more energy efficient than conventional on/off units, but a failed circuit board can throw that way off. I don't know that being energy efficient is important in our situations because we often pay a flat rate for hookups whether we use a lot or not, and when on a generator the difference might not be greatly noticeable in fuel use, and it is not healthy to run a generator with light loads. Running off batteries might be where they would shine in comparison, but if they are a cheap product that does not last.... :-\
Really do suggest the safest and most dependable are roof tops. I accept the risk of a failure. that is why I have 3 separate units. Performance is far above roof top units and noise is so much less. I hate the roof top noise is why I ventured another way. I can also do my own repair any keep repair tools and 410 with me. have not used yet. Do suggest for the non HVAC guys go the roof tops!! Make your own choices!! I have been watching for the inverter type roof tops to come to USA. Would like to try one on Andy's toter home.
I didn't want roof tops on a Eagle and Mini splits were available then but I chose to go with the Crusiair I loved those units you could turn the fan from 0 to fast 20 years of service and they are still going, yea they were a little pricey to buy and install but they were trouble free
Quote from: robertglines1 on July 16, 2016, 06:55:07 PM
Really do suggest the safest and most dependable are roof tops. I accept the risk of a failure. that is why I have 3 separate units. Performance is far above roof top units and noise is so much less. I hate the roof top noise is why I ventured another way. I can also do my own repair any keep repair tools and 410 with me. have not used yet. Do suggest for the non HVAC guys go the roof tops!! Make your own choices!! I have been watching for the inverter type roof tops to come to USA. Would like to try one on Andy's toter home.
Thx. Inverter type rooftops?? I haven't heard of these. Can you tell me more?
Quote from: luvrbus on July 16, 2016, 07:14:43 PM
I didn't want roof tops on a Eagle and Mini splits were available then but I chose to go with the Crusiair I loved those units you could turn the fan from 0 to fast 20 years of service and they are still going, yea they were a little pricey to buy and install but they were trouble free
Actually what I mainly want is QUIET. The noise level in my coach is 80dB+ when the forward AC is running overhead. Efficiency would
be nice but QUIET and COOL is ESSENTIAL.
Ideas?
Quote from: tbfisher on July 16, 2016, 08:14:34 PM
Actually what I mainly want is QUIET. The noise level in my coach is 80dB+ when the forward AC is running overhead. Efficiency would
be nice but QUIET and COOL is ESSENTIAL.
Ideas?
Mini Splits are not all quite we have a few at the offices in the restaurants you turn 1 on high 480 CFM you can't talk on the phone till you turn it down
Quote from: luvrbus on July 17, 2016, 06:47:13 AM
Mini Splits are not all quite we have a few at the offices in the restaurants you turn 1 on high 480 CFM you can't talk on the phone till you turn it down
It is my understanding that they don't operate like a conventional HVAC system....i.e. full on, full off.......Rather they have PID(Proportional/Intergrative/Derivative) thermostat/controllers that run the system at a constant level where cooling(heat extraction) = heat gain. This tends to be at a much lower speed and thus at a much lower noise level. Years ago, I built and installed my own hydronic heating system for a 99 38ft Dutch Star DP. It replaced the Suburban propane furnace and used an Espar diesel coolant heater. I built a microprocessor controlled circulation fan motor driver that worked the same way. Initially when the system started up and the coach was cold, it ran at max speed and gradually decreased the fan speed until equilibrium(heat input = heat loss) was reached. It then maintained that equilibrium by adjusting the fan speed as necessary. This tended to be a very low and barely audible fan speed and at a very low firing level for the Espar. It worked very well. IMHO it was better than any AquaHot, etc.. that I've seen and a LOT less expensive. The following is a diagram:
You can manually override ours we do it all the time when the makeup air doesn't keep up with the air (AC) the hoods remove.Our units are the Innova 3 speeds 480 hi,420 med and 320 on low that's all I know
Quote from: tbfisher on July 17, 2016, 07:37:34 AM
It is my understanding that they don't operate like a conventional HVAC system....i.e. full on, full off.......Rather they have PID(Proportional/Intergrative/Derivative) thermostat/controllers that run the system at a constant level where cooling(heat extraction) = heat gain. This tends to be at a much lower speed and thus at a much lower noise level. Years ago, I built and installed my own hydronic heating system for a 99 38ft Dutch Star DP. It replaced the Suburban propane furnace and used an Espar diesel coolant heater. [red,2,300]I built a microprocessor controlled circulation fan motor driver that worked the same way.Initially when the system started up and the coach was cold, it ran at max speed and gradually decreased the fan speed until equilibrium(heat input = heat loss) was reached. It then maintained that equilibrium by adjusting the fan speed as necessary. This tended to be a very low and barely audible fan speed and at a very low firing level for the Espar. It worked very well. IMHO it was better than any AquaHot, etc.. that I've seen and a LOT less expensive. The following is a diagram:
now you've got my attention :) can you build another or suggest one off the shelf ?
Quote from: eagle19952 on July 17, 2016, 05:09:23 PM
now you've got my attention :) can you build another or suggest one off the shelf ?
I am a retired(mostly) physician/engineer EE hobbyist. I will help you as much as I can but can't build it for you. Since
PID controllers are everywhere, I suspect that there are some off the shelf out there but don't
know of any off hand. Here's what I used as a starting point
many moons ago:
http://learn.parallax.com/tutorials/language/pbasic/pid-control (http://learn.parallax.com/tutorials/language/pbasic/pid-control)
I used a Basic Stamp 2 microprocessor. The input was simply a voltage divider circuit with
a thermister which sensed room temperature. The output was a simple low current(1amp)PMW
controller to controlled the speed of two high efficiency 1 amp EBM/Pabst tube axial fans pushing air through the
heater core and then out the floor ducts.
If you are interested in more details you can email me privately and I will help as much as I can ;)
Quote from: tbfisher on July 17, 2016, 06:29:57 PM
I am a retired(mostly) physician/engineer EE hobbyist. I will help you as much as I can but can't build it for you. Since
PID controllers are everywhere, I suspect that there are some off the shelf out there but don't
know of any off hand. Here's what I used as a starting point many moons ago:
http://learn.parallax.com/tutorials/language/pbasic/pid-control (http://learn.parallax.com/tutorials/language/pbasic/pid-control)
I used a Basic Stamp 2 microprocessor. The input was simply a voltage divider circuit with
a thermister which sensed room temperature. The output was a simple low current(1amp)PMW
controller to controlled the speed of two high efficiency 1 amp EBM/Pabst tube axial fans pushing air through the
heater core and then out the floor ducts.
If you are interested in more details you can email me privately and I will help as much as I can ;)
This looks like it might be adaptable to drive a fan speed controller:
http://tekmarcontrols.com/products.html (http://tekmarcontrols.com/products.html)
Quote from: tbfisher on July 17, 2016, 06:38:54 PM
This looks like it might be adaptable to drive a fan speed controller:
http://tekmarcontrols.com/products.html (http://tekmarcontrols.com/products.html)
I used two tube axial fans from this company. They were very efficient, quiet and only drew 1 amp
each @ 12V. Of course since the heat exchangers and fans were all mounted in the basement under
the floor duct, this contributed to the quietness of the system. Don't recall the specific model number:
http://catalog.ebmpapst.us/search/search.asp (http://catalog.ebmpapst.us/search/search.asp)
Checkout the specs on these. The AC 420 II model is rated at 31,400 Btu requiring only 61 amps @ 12VDC and is only 6" tall.
https://www.eberspaecher-na.com/fileadmin/data/countrysites/EB_Kanada/pdf/EB_AC403_420_Spec_WEB_READY_01_27_15.pdf (https://www.eberspaecher-na.com/fileadmin/data/countrysites/EB_Kanada/pdf/EB_AC403_420_Spec_WEB_READY_01_27_15.pdf)
I would be very skeptical but having owned one of their hydronic coolant heaters before, the German quality engineering is obvious.