Mini-Split Heat Pump

[Kenny]

Anyone ever use a Soleus Mini-Split Heat pump for both your AC and heat? Kenny

[robertglines1]

using on project now..only problem is condensate tank drain un level and leaking when not level or in motion..solution  get one that has drains on both ends of tank or build a catch tank around unit and drain from it..don't  know if the brand your looking at has dual drains.conquer that problem and they are great...several members have them and have had no problem with drains..Including a close friend in his MCI 8 and he is a HVAC guy..Pay attention to drains .wether one or two and I think you will be happy...he used two twelves and said in 90 plus weather they are not maxed out.Bob

[Kenny]

Bob, are you or your friend using the Soleus brand heat pump? If not, whose are using?
Kenny

[robertglines1]

LG-brand; don't know if there is much difference..just what our local supplier has..cheaper than internet..

[twocnusa]

we are using a mini split air and heat system 12500 btu made by ramsond. cost about 750.00 draws 8amps, works great. been in mid-west and southren states all summer.has one drain hose, no problems.  ron

[Handyjim]

Twocnusa:  Where do you mount the outside unit?  What about ventilation?

[pvcces]

Kenny, we have been buying heat pumps for our apartments in Ketchikan, Alaska. Most of the Chinese units have been fine, but some don't have as good of performance.

The Soleus is one of those brands that we avoid. The low ambient ratings are worse than most, and if you have been checking around, the market is about flooded with them.

To get good units, do not accept any that use heat strips or show a low ambient rating above 19 degrees F. The R410A really improves the low temperature heating capability. Our 19 degree units have worked down to 11 degrees, and didn't quit.

You can buy a better unit that uses less power and is rated down to -4 F. For running on a generator, you will probably much prefer inverter units, as they will change generator load gradually, where the non-inverter designs turn on and turn off, changing the generator load with large swings.

The better units will generally be quieter, but be sure to check the ratings. Most of ours are in the low 40s for sound ratings, and there are some models that carry ratings in the high 20s. This makes them a lot quieter.

We won't accept any if the seller will not disclose all the specs that matter to us. If you go by that and check out the specs that you are furnished, you should get a handle on them.

For what it's worth.

Tom Caffrey

[Kenny]

Tom, Great feedback. Was thinking about the inverter unit for smooth operation. Want a unit with a small condenser box. Any recommendations on price vs performances?
Kenny

[buddydawg]

I have 2 Mini-Split Heat pumps.  I have a Sanyo 12K BTU in the front, it has the inverter compressor.  It is a very quiet unit, I have had it installed for 2 years with no problems.  The compressor is mounted under the bus and also draws air from under the bus and exhausts through a vent on the side.  The condensation pan has a drain on both sides so there is no issue with leaking.  It is a very nice unit although rather pricey ($1500).

I also have a Klimaire 12K BTU Mini-Split HP in the bedroom.  I just installed it 2 weeks ago.  I put the compressor where some of the stock coach equipment was located on the top rear of the bus.  It is concealed by the stock fiberglass cover.  It does not have the inverter compressor and was half the price of the sanyo.  So far I am pleased, with both units running I can get the interior temp down in the 60's on a hot summer day.  Neither unit draws more than 10 amps and I have yet to have an issue with the generator cutting out (Onan 5K Watt).

I chose to go this route because I did not want to mount anything on top of the bus. I prefer the look of a clean roof. (I also prefer the look of a painted bus, but I am not quite there yet)

[twocnusa]

where i mounted my unit. look at our blog: ourbusandus.blogspot.com  When u get to our blog look at the left side, scroll down until u come to aplir. click on April and u will see where we mounted the inside and outside unit and much more.  ron

[artvonne]

  Could someone explain how these work, or direct me somewhere where I can read more about it?

 I am considering a bus conversion where I would use the OE evaporator and condensor, replacing the DC fan motors with 240 volt AC motors, and run a small residential air conditioning compressor, about a ton or so capacity, for cooling. I imagine it wouldnt be that hard to reverse the flow and make it a heat pump? Any advice for or against, or if it would even work would be kindly accepted.

 

[twocnusa]

from one newbie to another (ha ha) hi artvonne, look up  acworld.com  then look at mini-split system's. it will tell u how they work and i found they had the beat price.  ron

[TomC]

Artvonne- About the only way you'll be able to use the stock bus A/C's evaporator and condenser is to run the A/C with a 10ton electric compressor-which would be out of line with what you need. 

A little on A/C basics-the sizing of the evaporator, condenser, and compressor have to be all balanced to work properly together.  Using the giant condenser, may not be a problem, but trying to us the giant evaporator with one or two small compressors would create a cold spot at one corner of the evaporator and not really much of any cooling coming from it.  The OEM A/C equipment is both very large, very expensive to keep up and entirely too large for what we do (unless the entire system is still operational).

On my bus, with 2.25" of sprayed insulation (I have a 40x102 transit with large windows) I can keep the bus cool running two of the three roof top air conditioners when running down the road.  Insulation is the key.

Instead of experimenting with trying to keep the on board existing A/C, I would suggest you rip it out and install either conventional roof top airs (which really work well and are cheap), use RV style basement air (which keeps the roof clean, but takes basement space), or create your own with mini-splits, or like what I'm going to do-use the Duotherm Penquins as basement airs since they are the only roof top air that has a squirrel cage blower for the condenser that can be ducted.  Then you have a cheap roof top air in the basement out of site.  Good Luck, TomC

[artvonne]

   Thanks for the insight Tom. Years ago I learned that a large condensor was a big key to keeping cool. Sizing the evaporator I didnt know about, but it makes sense. I am curious though what some are calculating for heat loss/gain values. The original AC system was capable of removing the heat of 40 plus passengers while running through the Arizona desert in 110 plus heat. These busses were poorly insulated and do have a lot of glass, but were only talking about roughly 300 square feet of living space. Remove 4 windows on each side, close off the rear glass, and double insulate it all with high performance insulation, it would seem a 10,000 btu air conditioner should be more than sufficient, but its not. Many are claiming 35,000 btu furnaces are only good down to 0-10F. Where is allthe heat going??? Are you guys insulating under the floor?

[Kenny]

Tom, did you know Duotherm has a combination AC/Heat pump that is priced reasonable? Don't know though if it has the ducting needed to put in the basement.
Kenny