Mini-split two heads and Transformer

[luvrbus]

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   

[tbfisher]

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?

[tbfisher]

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?

[luvrbus]

   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   

[tbfisher]

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:
 

[luvrbus]

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

[eagle19952]

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 ?

[tbfisher]

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
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

[tbfisher]

   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
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

[tbfisher]

This looks like it might be adaptable to drive a fan speed controller:
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

[tbfisher]

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

I would be very skeptical but having owned one of their hydronic coolant heaters before, the German quality engineering is obvious.