If I were to consider buying a 240 V mini split air conditioner for our coach, could I use a T240 transformer to step up the voltage to 208 V? Would I lose efficiency by doing this? Does that defeat the purpose of having an efficient mini split?
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I am planning to do the same. I'm looking at using a mini split with two heads. Each head would be 12,000 btu's but the outside unit would be only 18,000 BTU's. I am looking at using a trans former to go from 120vac to 240 vac. You have some loses to heat but my advisors say it should work. The mini splits are inverter based should be tolerant to voltage droops. We used an amp probe on a comparable unit and found the amp draw ramps up slowly, no spikes. At present, I have made the decision to go ahead with my plan, but I am working on funding it.
Art
Would be a lot easier with the 120/240v transformer since these are easy to find .Not so easy to find with 208/240 especially in the lower kva ratings .Despite my lack of knowlege on converting btu 's to amps/wattage ,how many amps are you looking at?? About forgot all this stuff since retiring ,I think that if you are 3 kv (3000 watts) you can reverse hook the transformers with no loss in KVA rating.
They make mini-splits up to about 14,000btu at straight 120v. You'll be much happier without the step up transformer. Just buy two units and put one on each leg. Good Luck, TomC
Just stick to ducted roof tops you full timing and starting a family you are going to need the bay and wall space
Scott,
Stick with 120v. Youll thank me later.
We had straight 240 from the generator and it was a pia. This also greatly limits the places youll be able to stay.
The transformer will work initially but I think over time it will be troublesome and down the road youll have issues with not only the transformer but also the mini-split.
Call me if you want to talk about minisplits. Ive had plenty of success and failure in that department.
-Sean
A simple step up center-tap transformer will be around 97% efficient, depending on the model. Close enough to 100% that you can about ignore the loss. It will put out single phase center-tapped power, and normally you look for 2:1 on the voltage, so 120 in you get 240 out, center-tapped for two 120 volt legs exactly the same as a house. 208 volts is usually found with three phase power where the legs are 120 degrees apart, not 180 like house current. You won't get 208 volt three phase out of a normal step up transformer that is fed with 120 vac.
Brian
Quote from: Seangie on May 30, 2016, 06:34:27 AM
Call me if you want to talk about minisplits. Ive had plenty of success and failure in that department.
-Sean
Do tell, do tell. Or would it be better in it's own post so as to not jump the post.
Quote from: krank on May 30, 2016, 09:10:33 AM
Do tell, do tell.
Yes, please share, I am also interested in this realm. I hate roof warts.
happy coaching!
buswarrior
Roof warts do look bad-but show me a $2 million band bus with anything but 5 roof tops. You can't because they need the storage space, the roof tops are easily replaced and now most high end buses have roof liners (fences) around the perimeter where you don't see the A/C's
My bus is set-up with 12/24 and 120 systems; Trace 4024 and Honda EV6010. I went with mini-split 24,000 btu compressor, 9,000 btu in the bedroom, 12,000 btu in the kitchen/living room and 18,000 btu over the driver. I run it off a 5,000 watt 120/240 transformer on the road and camping where 50 amp isn't available and switch it to a 240 circuit where 50 amp is available. No problems in 4 years.
Every build, every decision, is a compromise, biased towards the builder's particular wants, needs or delusions?
The transformers are intriguing. Whether powering a mini-split, or other 240 volt appliance, such as an electric drier, electric cooking units, etc...
keeping the generator wired for 120 (another set of reasons), and the ability to make 240 at a 120 campsite is a whole 'nuther set of fascinating variables for the busnut theorist to ponder?
If thinking was money, we'd all be rich!!!
We need more typing about the selection and use of transformers!
happy coaching!
buswarrior
As with all things electric, start with power. I'm getting a new heat pump installed in my house, and it has a 20 amp fused supply (it's a 1 ton unit). So if I wanted to use a transformer to run it, I would look at compressor draw being less than 20 amps at 240 volts, so 4800 watts, and starting loads of less than 3 times that, so I might buy a 10 KVA transformer. Now I might look at available supply. I have a 30 amp generator, and my typical plug in at home or campsite is also fused at 30 amps. That's 3600 watts, and it will transform into 3600 watts less a bit for efficiency at 240 volts, so that is 15 amps at 240. I still might look at the 10KVA unit, or I might downsize a bit to 6500 or 5000 KVA. You want the whole thing to have quite a lot of headroom so you minimize voltage sag when the compressor motor is starting, although selecting a modern Mini-split with inverter driven and variable speed motors will really lower the power requirements.
As with everything, you get what you pay for. A nice thing to have is a regulated or protected output, you can get ones that can boost low campground voltage or that have surge protection and output breakers. At the size you would be looking at they don't have outlet plugs but need to be hardwired on the supply and output side into distribution boxes.
Example of a unit that would probably be typical is here: http://www.220-electronics.com/10-000-watt-diamond-series-voltage-transformer-with-regulator.html (http://www.220-electronics.com/10-000-watt-diamond-series-voltage-transformer-with-regulator.html)
This step up and step down transformer thing is done all the time. I'm looking at a step down transformer right now that steps around 7K volts single phase to center-tapped 240 volt, it's bolted to a pole on the street outside my house. Typical transformers, if they are dry (some are full of oil) are massively reliable. You open up a 60 year old piece of electronics and you don't even worry if the transformers still work. The tubes, the capacitors, the resistors can all be toast, but you are going to have voltage!
The only thing that will kill a dry transformer is a Direct lightning hit !!!
Ok reading between the lines here, it could be done, but it sounds like the 3 phase could be an issue. I want to run something like an 18,000 BTU unit with two zones. Bedroom and rest of coach. Multi zone splits only come 240 volts
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Quote from: Scott Bennett on May 30, 2016, 09:26:44 PM
Ok reading between the lines here, it could be done, but it sounds like the 3 phase could be an issue. I want to run something like an 18,000 BTU unit with two zones. Bedroom and rest of coach. Multi zone splits only come 240 volts
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but the 3 phase is not a part of your discussion. any 220 volt appliance single phase will run on 240.
208 will too, just single phase single phase
208 just happens to be common to 3 phase also, as well as 377 IIRC.
Three phase power is only available in industrial areas, as a rule, and powers large industrial motors. I'm not aware of any residential mini-splits that would require three phase power. 220 or 240 VAC in residential use in North America (not positive about Mexico) is what I call center-tapped 240 VAC. The transformer that feeds your house has two live outputs and a neutral. The neutral is the center tap position, and is referenced to ground, or zero volts. The two legs are 120 volts each with reference to neutral, and add up to 240 volts between each other.
Brian
You can do three phase but a transformer will not convert single phase to three phase.You would need a rotary phase converter available from Ronk.
Quote from: bigred on May 31, 2016, 06:09:59 AM
You can do three phase but a transformer will not convert single phase to three phase.You would need a rotary phase converter available from Ronk.
still not a bus/mobile option.. it would consume a lot of storage space, more then a busnut would want to sacrifice.. not for me.
Actually a phase converter probably would not be any bigger than a transformer.
Quote from: Scott Bennett on May 30, 2016, 09:26:44 PM
Ok reading between the lines here, it could be done, but it sounds like the 3 phase could be an issue. I want to run something like an 18,000 BTU unit with two zones. Bedroom and rest of coach. Multi zone splits only come 240 volts
Scott, The only three phase is coming out of the inverter in the mini split. I'm going to use a two zone unit. I found the same you did that they only come in 220/240 vac. You must have watts in to equal watts out, therefore it takes twice as many amps at 120 vac as the unit is rated for at 240 vac. My friend the HVAC engineer and myself put an amp probe on an acutal, installed and operating unit to read the amp draw. We found that the unit used less amps than the manufacturer specified, but more important to us is that it didn't have "spike" when first coming on the current draw "ramped" up over a period of time. I feel both of these characteristics are because of the inverter technology. The inverter is single phase in and three phase out. The fans and compressor are three phase because the speed of the compressor and fans is easier to control three phase and the units will be lighter. Also, the remotes BTU's can add up to more than the outside units BTU rating. They will compensate automatically.
I talked to my business neighbor, the motor rebuild and repair shop about the transformer and he saw no problems. He did recommend that I over size by 50%. I don't have my data at home, but the transformer that I selected is around $100.00.
Art
Ok. I'm in way over my head on the phase power thing here. Guys, remember I'm just a former computer tech consultant turned singer lol.
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Quote from: Scott Bennett on May 31, 2016, 07:20:17 PM
Ok. I'm in way over my head on the phase power thing here. Guys, remember I'm just a former computer tech consultant turned singer lol.
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now i understand, .... Art has it. a 100$ transformer is probably the size of a shoe box...the 3ph is on the out not the in..o no roto anything is needed.
you could figure a 220 pole/rv park source and a secondary 110v/ transformer alternative when the 220v park pole was not available. I would.
I am the original S in KISS so I'm following this with interest but not a lot of understanding ... but I kept everything on my coach 120V for the simplicity of it. Is 240V worth the complication of transformers and additional circuits and breaker boxes and wiring? I'm thinkin (may be wrong, don't forget the "S" part) that many quality inverters can be "stacked" or combined to get 240V out of two inverters but again, more complication.
What is my weary little brain missing here???
How did the 3 phase get into this are transformers efficient. I don't know of anything that you would put on a coach that would be 3 phase. I would think all large coach,s are wired for 220 volts 50 amp.
My coach is all electric and has a 220 volt stove top (now you can buy 120 stove tops). If we only have 110 volts we use an electric fry pan or start the generator.
Jack
Art, please share the numbers in your plan.
If a $100 transformer lets me avoid wiring for 240, but lets me have a 240 appliance....
a whole new world opens up....
Unfortunately, transformers were on the curriculum of that high school electrical course that got cancelled due to low enrollment, long ago and far away.
Very interesting!
happy coaching!
buswarrior
Ok so ignore 3 phase. My
Muddled mind. Here's my actual finally question:
Can I somehow make a mini split set up to run on 208v input power run on 120volts? Not a big one, just something in the 15,000 BTU range
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If you read the informative reply from Art Gill, you see that in some literature or from a technicians point of view, the motors inside the Mini-split might well be three phase motors. Why? Because three phase motors are smoother, quieter, more efficient, more reliable than single phase motors. More why? Because the mini-split uses inverter technology (similar to but different in application from the pure sine wave inverter that you use to produce high quality AC from your batteries) to take in the incoming power and change it to something that really efficiently drives the compressor and condenser/air handler motors very quietly and at variable speed. The fact that the motors happen to be three phase is irrelevant, they could as well be any number of phases including zero for a DC motor. It just totally doesn't affect a thing as far as powering a mini-split AC unit is concerned. Any mini-split type AC unit sold in North America for residential use is going to have an option for single phase power, either 120 volts or 240 volts nominal, the only difference being the amount of current and hence the wiring gauge needed to hook them up. End of story... I hope! :o
This actually answers a question I had for quite some time. My buddy had a fan motor fail in his heat-pump at home, a 5 ton unit with variable speed this and that, inverter controlled. The new motor was close to $1,000! until the dealer got involved and it was under warranty. I could not figure out how a fan motor could cost that much.
Scott, please share the make and model of your unit that requires 208 volts. Do you already have it, or are you shopping? Every single one I looked at has a voltage input range from 208 - 230, 60 Hz single phase. Every single one could be powered with a step up transformer like the one I posted a day or two ago.
OK, I thought I would continue confusing the heck out of people and explain why the voltage input range is 208 - 230 volts, and why I keep saying 240 volts is the normal residential supply voltage.
In the USA and Canada, the national standard for AC line voltage at the source is actually 120 volts plus or minus 5%. It's supplied to a house at anything from 110 volts to around 125 volts, depending on the region and the distance from the source - the power pole transformer. All of these voltage levels are acceptable and equipment is designed to accommodate the range. In the olden days the standard for voltage was anywhere from 110 to 115 to 117 to 120, and they are effectively interchangeable.
In a normal residential hookup, power is delivered to the house with a single phase 240 volt feed that has three components - two 120 volt live feeds that are opposite in phase (but still the same phase) and neutral, which is tied to ground and is a reference. So you get your two 120's and if you connect across them you get your 240. That is the nominal voltage - it's usually lower, has around a 5% tolerance and equipment people put 230 on their spec sheets. Which is all fine.
In a light or heavy industrial situation, the power feed to the building will be three phase. It's supplied over four wires - one for neutral, and three live feeds to carry the three phases. Each phase is 120 degrees apart from the other two, so instead of a power pulse every 1/60th of a second (60 Hz), a motor would get a power pulse every 1/180th of a second, three pulses per rotation. Hence smoother, quieter and more efficient. In a typical light industrial building the power feed will be 208 volt three phase, other standards are 440 volt, 480 volt, 575 volt. A big building will have a power plant with transformers to take in the high voltage and divide it down to whatever the machinery or equipment happens to need, and it gets quite complicated. But there is always a need for plain old 120 volt 60 hz power. If you take a 208 volt three phase system and measure the voltage from one hot leg to neutral, it will be 120 volts. If you measure from one leg to another leg it will be 208 volts (they don't quite add up because the two legs are only 120 degrees apart, not 180 degrees apart like they are in a single phase system. All buildings with three phase power coming into them will normally have an option to supply 120 volt for all normal desktop type stuff, and 208 volts for higher power but non-industrial things like air conditioners.
So that is the sad story of why you see both 208 and 230 volt specifications on residential type air conditioners - because they might be installed in a building where the power is derived from an industrial three phase supply, so they are built with the option to use that type of power.
Quote from: bevans6 on June 01, 2016, 09:05:42 AM... So that is the sad story of why you see both 208 and 230 volt specifications on residential type air conditioners - because they might be installed in a building where the power is derived from an industrial three phase supply, so they are built with the option to use that type of power.
So if they're used at 208, it's still a single-phase service. And if a 120V unit is used and it's wired in properly, it's single-phase and half-a-full-phase sine wave - just like it would be if it were wired into a single leg of normal 240V service?
I live in a 50 year old house in a little country town; everything here is old-fashioned, behind the times, and low-tech. Every time I measure voltage anywhere, I see 119.5-121V (or 240V +/- a fraction). I'm happy to call it 120 and 240 volt.
Can I somehow make a mini split set up to run on 208v input power run on 120volts? Not a big one, just something in the 15,000 BTU range
yes.
with the proper transformer.
are you absolutely sure that the unit is restricted to 208v. it is relatively uncommon for an electrical device not to be operable in a voltage range.
ex: 208v/220v or 220v/240v 0r 208v/240v etc.
exactly what unit are you wanting ?
Brian is spot on.
These AC's will run on 220v (230, 240...all the same, 180 degrees) all day long with no problems.
Here are some power issues you'll need to think about when you go to a mini-split -
1. Construction - Most of these mini-splits (That we are looking at anyways) are cheap and affordable because the electronic components in them are not high end. They are designed to be hooked up to a 220v service that is constatnly supplying good power 99% of the time. A power outage wont kill them but power off/on/Off/on/off/on does not contribute to the longevity of the electronic components in these devices
2.The issue you could have with a transformer is that you need to make sure its a heavy duty transformer capable of delivering clean power to both legs 100% of the time. A 120v unit could pull as much as 12-15 amps on startup, A 220v unit is going to pull about 8-10 amps on startup. Your going to want to get a 4000-5000 watt inverter. Most of the wattage listed on these inverters is the wattage for 110v electrical.
3. Power quality is another issue why you might not want to take this road. Usually you cannot tell what type of power you are getting from a park pedastal. It could be solid 220v tested when you hook up on Thursday afternoon but by the time Saturday night hits and the park is full and everyone is running 2 or more AC units in the middle of July you could see a voltage drop that might be big enough to add quite a bit of heat to the circuitry in your mini-split. Even if you have a power regulator that adds voltage from your battery bank to correct the voltage its still not the type of power these mini splits are designed to run on.
4. Using a 220v Mini Split gives you a single point of failure. If you have a 2 head or 3 head unit and the single outside unit fails, you can't run anything until you get it fixed. And if it does fail you know it will be that 100 degree day with 60 percent humidity in August. Unless you spend a good ton of money, this outside unit is not made to be replaceable nor does it have field replacable parts on it. They are meant to be tossed. The first unit I bought was sent with slightly newer evaporator/head units than the compressor, I'm talking the next model number up. Yet the outside unit wasn't compatible with those newer evaporator units. I ended up having to ship all of them back (After installing and paying AC guy to come up and setup) and get something different. So within 2 months the brand new parts that I ordered were out of stock, no longer available, no parts to replace or repair and not backwards/Forwards compatible with the new model.
5. Airflow, Airflow, Airflow - You cannot get enough air to flow through these 220v units. They get hot quick. They are made with just enough fan to keep them running. By putting these units in a bay expect that you will probably have to keep a bay door open to keep the outdoor unit from overheating. The best way to do it would be to build the outside unit right to the exterior of the bus and have a tunnel through to the other side of the bus to pull fresh air in. other than that you just are not going to be able to get enough air through the exterior unit to cool it. 120v 9000btu units don't get as hot. 120v 12000btu units are going to get pretty warm, its a 9000 btu unit beefed up to 12k.
6. Fixtures - Not designed to be bounced all over at 70mph. Cracks in the copper inside the unit and at the attachment on the exterior of the unit can appear. They are not designed with shock absorbers. If you have the screw on connectors, make sure you sweat them on so they dont back off.
7. They are badass. These mini splits are sooooo effecient. I ended up with a 24k btu (2x12k) unit and on our first trip we had no open windows, driving to Florida on a 96 degree day and within 15 minutes of being at the park it was ICE COLD on that bus. They are very quiet and work extremely well. I just don't think that they are ready for fulltiming on a bus.
I know there are quite a few bus nuts out there that use them. How many of those bus nuts are fulltiming, constantly putting miles down and running their units 12 months of the year? I know that Dave & Amy (TIKVAH) have a unit on their bus. It works very well. Dave has lost a unit to park power (we were in the same park and tested that power and didn't see anything unusual, may have been a spike or slump) but had to figure out how to get another unit to replace it. It was a stressful day for them. They only have one unit and it keep their entire but very comfortable. How long until they loose the new unit? I'm hoping it lasts 5-6 years. Trust me, i want to see these mini-splits work, I'm cheering for all you guys that run them.
You just gotta make sure you understand the risks that come along with a project like this. You can make all the changes and modifications to make it work but as soon as you loose it, there is no insurance, warranty or anything else that is going to cover your 1200 - 4500.00 investment.
Thats my 2 cents.
-Sean
PS - On my next bus build I'm going to engineer the mini-splits into the bus, but I;d stick with (2) 120v units.
in service 25 years..by me for 14. new condenser fan motor 2007, new compressor 2011, new A coil 2012. the a coil was fine but the condensate pan rotted/rusted out so i decided to replace it..
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2FImage022-1.jpg&hash=f54155314a36d8f8398f1c572ccc1607382a8025)
in this photo you can see the air handler/medicine/broom/storage closet. and a small portion of the duct work.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2F0295035-R1-018-7A.jpg&hash=61fca6ac9a0d07fcb8465cf7720e2b59b8cac343)
the duct is behind/integral to the cabinets curb side seen here:
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2F0295035-R1-054-25A.jpg&hash=0dd8313b56a6aeef45ec86c3d90a1ad73f16983c)
Quote from: eagle19952 on June 01, 2016, 12:34:22 PM
in service 25 years..by me for 14. new condenser fan motor 2007, new compressor 2011, new A coil 2012. the a coil was fine but the condensate pan rotted/rusted out so i decided to replace it..
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2FImage022-1.jpg&hash=f54155314a36d8f8398f1c572ccc1607382a8025)
in this photo you can see the air handler/medicine/broom/storage closet. and a small portion of the duct work.
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2F0295035-R1-018-7A.jpg&hash=61fca6ac9a0d07fcb8465cf7720e2b59b8cac343)
the duct is behind/integral to the cabinets curb side seen here:
(https://busconversionmagazine.com/forum/proxy.php?request=http%3A%2F%2Fi1207.photobucket.com%2Falbums%2Fbb468%2Fdphalaska%2F0295035-R1-054-25A.jpg&hash=0dd8313b56a6aeef45ec86c3d90a1ad73f16983c)
Don - Thats not a cheapo 700$ mini-split. Thats awesome though :) Ive seen those pics before.
Curious - Do you have to leave the bay door open when you run it?
Quote from: Seangie on June 01, 2016, 12:41:44 PM
Don - Thats not a cheapo 700$ mini-split. Thats awesome though :) Ive seen those pics before.
Curious - Do you have to leave the bay door open when you run it?
No... but when i feel sympathetic... i do :) we both know that heat is the death of compressors :(
i have often run it going down the road.
i had no idea the mini-splits were a $700.00 deal :(
the new a-coil installed was 1300$. but i decided it was a good investment :) the day is coming when a SEER rating will make rebuilding/parts for R-22 systems impossible if not illegal.
but..if you consider the 2 million dollar coach with 5 roof tops... then the price is comparable and i have never found a residental HVAC guy who didn't want to work on it ... beats the heck out of an attic installed air handler repair in Florida in July :)
This is all so fascinating to me... Ok, shanks is like a brother to me so I take any of his advice to heart. Heck, the guy helped me change brake calipers on my truck in front of his bus in Texas. I desperately want a higher seer a/c and heat system. Heating with propane or electric resistance is expensive. Seriously, our rv park power bills are regularly in the $200 a month range summer and winter. It really stinks to me that we are somewhat prisoners to the lame rv industry's roof tops that have got to be the biggest power jobs in the climate control business. Not to mention they look hideous and add height to our already tall bus. Sean's right, we have an intense schedule and having something somewhat exotic break down on me in the summer or winter would be lame. So if I wanted to install the most efficient a/c heat pump according to the KISS principle in my coach, what should I be focusing on?
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I would find out if 220-240 is an option rather than 208. The 120 to 240 transformer is a standard where a 120 to 208 maybe a special order. My design keeps my coach all 120 vac and the transformer will only serve the mini-split. As with most things you buy you get what you pay for and that is true with mini-splits. There is/was some cheap imported mini-splits that had no support. The unit I have had for a number of years has given me good service. I made sure the copper refrigerant lines were well attached and supported. My HVAC friend will not sell me anything but a Diakin AC because that what he sells and supports and we eat lunch together a number of time a week and if it fails he will hear about it at lunch every day. So buy a brand name that has his support.
My application is a little outside the box. My Eagle has a large compartment over the engine that had contained all the fans and coils for the over the road AC and heat and that is where I have my present outside unit and plan to install the replacement outside unit. They make a inside unit designed to fit in a 24 x 24 ceiling grid and we plan to put one in each old escape ceiling hatch. That will require a cover of some type on the roof over each unit. My plan is to run the refrigerant lines down the roof to the outside unit in the compartment over the engine.
We studied the manufacturers specifications for current draw at 220 vac and then we ran a real world test on an unit of the same size that was installed in the garage of my HVAC friend. We found that the current draw was less than specified and that they was no spike of current in rush on startup. We have decided on a 4000 watt transformer. That will be 33 amps in at 120 vac and 16 amps out at 240 vac. A transformer is inert as far as electronic components go. It is two coils of wire, in this case, one has twice as many coils as the other and a core of steel. A transformer only works on AC current.
Art
What are your thoughts on these new kingtec solar air conditioners? http://kingtecsolar.com/products/
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back at square one... what percentage of your life is boon docking ?
there is nothing as dependable/efficient as all electric.
there is zero risk of carbon monoxide.
two fan motors and a hat full of limit switches fixes almost any problem.
but..3-4 1200 watt electric cubes are almost as effective... for heat.
i feel your distress :(
i hate it when my SO is not warm ...
to anyone who wants to answer ... why are you opposed to wiring a 220v service coach ?
Quote from: Scott Bennett on June 01, 2016, 06:30:39 PM
What are your thoughts on these new kingtec solar air conditioners? http://kingtecsolar.com/products/ (http://kingtecsolar.com/products/)
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where were you going to source 48v DC ... ? Reliably ?
Scott - Do 1 rooftop and 1 120v mini-split. Youll most likely only ever need the mini split and you can have the rooftop as a backup.
We ran both rooftops most of April in Texas and our electeic bill was 65$. I think your fridge is the other 135$.
-Sean
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Don it comes with a 110v power supply for pole usage. It just appeared to me that they put more effort into making the unit more efficient. But as shanks mentioned, maybe I'm chasing Pennies and it's costing me dimes. Those solar units are almost $3000
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Quote from: ArtGill on June 01, 2016, 06:26:48 PM... They make a inside unit designed to fit in a 24 x 24 ceiling grid and we plan to put one in each old escape ceiling hatch. ...
Art, I thinkl you might have just solved my biggest A/C problem. What's the brand/model of this 24 x 24 ceiling grid. How thick is it????
Thanks, BH
I have a 9 k split up front that cools the coach 90 % of the time up until it is over 99 f ( parked ) on the road then I turn on the roof rattler in the bed room for added cold this is in the mci
on the featherlite I have 3 roof a/c 's but I am shocked at how quiet they are ( well the front 2 our original the rear is 2 years old and is loader ) all are the 13.5 btu units ducted , yes I would like to have a split unit again but I can't see replacing them for no reason
you should find that with the help of the spray foam insulation it should be easer to heat and cool
dave
BH, Google "minisplit ceiling cassette"
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Quote from: Scott Bennett on June 02, 2016, 03:13:33 PM
BH, Google "minisplit ceiling cassette"
Sure is a lotta them informations there. That's gonna be harder to digest than a Buick!
Bruce, go to DaikinAC and look up FFQ09LVJU and download the Data sheet. The ceiling cassette is about 12 inches thick.
Scott, go to http://www.220converters.com/store (http://www.220converters.com/store) and search for THG-4000UD
Note: These are heat Pumps without heat strips, so the heat becomes less efficient as the outside temperature gets lower.
Art
Art, the newer mini split heat pump's are so efficient they work 100% down to 5° and will produce heat down to -13°F
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Quote from: ArtGill on June 02, 2016, 05:59:39 PM
Bruce, go to DaikinAC and look up FFQ09LVJU and download the Data sheet. The ceiling cassette is about 12 inches thick.
Scott, go to http://www.220converters.com/store (http://www.220converters.com/store) and search for THG-4000UD
Note: These are heat Pumps without heat strips, so the heat becomes less efficient as the outside temperature gets lower.
Art
Thanks, Art. All this is good info. As I look at my bus, I realize that probably my best setup is going to be for one of the long, low, thin air handler/evaporator boxes. One of those should fit right above the windshield, upper and lower. And I had in mind that I'd go for two separate 120V "outside units" - redundant, simple. But the idea of a 20 SEER single outside unit, with two evap units running off a transformer is starting to sound like a nice package. After all, I do have two levels to provide cooling for and I've never thought that that was going to be easy.
Quote from: Scott Bennett on June 02, 2016, 07:18:33 PM
Art, the newer mini split heat pump's are so efficient they work 100% down to 5° and will produce heat down to -13°F
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Wow, that is efficient. I had three Duo-Therm Heat Pumps back in the nineties that only worked down to about 40 degrees F, and then nothing. Two out of three failed completely within six months, so I returned them under guarantee and got my money back.