So I searched google and here no luck. What is the advantages to having the DC inverter type over not having it? How about 220 vs 110? I am cooling a 25x20 Garage in Phoenix, AZ. Does get down to 40's in the winter at night. Thanks!
Mini Split A/C. Innverter or non inverter?
- Thread starter AZpilot
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http://www.iqdrive.net/pdfs/Inverter_Reprint_FINAL.pdf
I'm making a lot of assumptions here from using inverter drives on other systems outside of the HVAC world.
I have used inverter drives, or more commonaly called VFD's in machine tools and one on my well pump. They eliminate the huge inrush current starting the motor. They run at a speed just adequate to keep up with the process. Kinda liken it to having an automobile with an accelerator, vs one that just has idle or wide open throttle. You've seen the kid at the stop light that takes off WOT at the green light only to slam on the brakes to get stopped at the next red light , and repeats it at every green light, vs the old guy in the other lane that cruises along at 20mph or so and makes every green light. The inverter drive is the old man cruising.
The above two things I just pulled from the internet but they explain how the system only runs as fast as it needs to to keep up with load. I would believe the savings potential of the units, but cannot speak the the quality and reliability.
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theoldwizard1
Well-known member
BIG savings on operating costs !
This technology has been around for several years, a lot longer overseas so I would not be concerned with durability. Stick with a major brand (Mitsubishi, Fujitsu, etc) that is sold and serviced locally and you'll be fine.
JakeKohl
Well-known member
"traditional" systems are either on or off. Inverter systems can speed up and slow down based on demand and put in more or less energy as needed.
Imagine it this way; you have cruise control in your car, right? Imagine what your fuel consumption would be if your cruise control could only cut the throttle or floor it at 100%. That probably wouldn't be very fuel efficient (not to mention comfortable). Now, go to an inverter system that is capable of any percentage between 0 and 100% so that you get a nice smooth throttle response that matches the power needed to maintain the set speed (temperature). It's old school vs. new school. Inverter technology is nothing new from a motor control standpoint - existing technology has just been integrated into HVAC systems. It's here to stay and will be the standard (if it isn't already).
Imagine it this way; you have cruise control in your car, right? Imagine what your fuel consumption would be if your cruise control could only cut the throttle or floor it at 100%. That probably wouldn't be very fuel efficient (not to mention comfortable). Now, go to an inverter system that is capable of any percentage between 0 and 100% so that you get a nice smooth throttle response that matches the power needed to maintain the set speed (temperature). It's old school vs. new school. Inverter technology is nothing new from a motor control standpoint - existing technology has just been integrated into HVAC systems. It's here to stay and will be the standard (if it isn't already).
I always use the driving analogy. Single stage is like driving at the drag strip. You wait for the green light and you are all in (system starts). You go as fast as you can until you cross the finish line(stat satisfied), and you shut her down and coast to a stop.
Inverter you pull out of the driveway, being careful of the nitwit neighbor kids, give it only the gas you need to sensibly get to where you are going. When you get to a secondary road you need a bit more gas (cooling) you feed in only the fuel you need. If it is really hot and you are on the hwy, you boot it an bring in the power (max cooling). As you exit the hwy you back off the gas. Sensible control.
No question the drag strip is more fun, but the "around town" driving is more efficient.
Inverter you pull out of the driveway, being careful of the nitwit neighbor kids, give it only the gas you need to sensibly get to where you are going. When you get to a secondary road you need a bit more gas (cooling) you feed in only the fuel you need. If it is really hot and you are on the hwy, you boot it an bring in the power (max cooling). As you exit the hwy you back off the gas. Sensible control.
No question the drag strip is more fun, but the "around town" driving is more efficient.
Trey T
Well-known member
I was at a trade show couple yrs ago and a lot of HVAC companies are using something similar to variable speed compressor to achieve SEER of 15 or higher. The main components are the compressor(s) (yes some of them have two) and the metering device.
If these mini-split uses DC motor, then the compressor pump can change the speed w/ the proper metering device to achieve higher efficiency.
If these mini-split uses DC motor, then the compressor pump can change the speed w/ the proper metering device to achieve higher efficiency.
JakeKohl
Well-known member
It's the exact same process as interior cooling - just in reverse. A "heat pump" is a system capable of reversing and either extracting heat from the interior space and expelling it outdoors (cooling the interior) or extracting heat from the exterior and dumping it into the interior space (heating it). Anytime the system can make air cooler going out of it, it can extract heat. So, for instance, if it is 15 degrees F outside and the outdoor unit can cool that air to 10 degrees F, it is extracting heat energy that it can dump into the interior of the building.
bazar01
Well-known member
A/C UNIT that provides heat inside the home in the winter without the use of electric heat strips is called a heat pump.
The inverter is a variable speed drive that controls the AC motor inside the sealed compressor to vary the speed of the motor/compressor for capacity control. The ability to vary the compressor speed makes it possible to control the cooling/heating capacity using just one compressor in the unit. Just like having 6 small compressors in one hvac unit and being able to stage from 1 to 6 compressors depending on the cooling load but using just one compressor on the inverter system.
Trey T
Well-known member
^since the motor is AC powered, is it 3-phase w/ VFD?
ssbtech
Well-known member
I'm still trying to figure out why none of the window AC units on the market are inverter types.
My big window AC uses a conventional compressor and it's noisy and annoying and bothers the neighbours. (Apartment).
That's another big advantage of inverters. They're very quiet and you don't have to hear the compressor kick on and off.
My big window AC uses a conventional compressor and it's noisy and annoying and bothers the neighbours. (Apartment).
That's another big advantage of inverters. They're very quiet and you don't have to hear the compressor kick on and off.
Charles (in GA)
Well-known member
The mini-split motor is not AC, it is DC powered, by the inverter. VFD for power tools such as lathes are a different animal, and stay AC, no inverter involved.
Charles
Jinks
Well-known member
Put a Mitisubishi inverter mini-split in my home shop last summer. The thing is SCARY quiet inside & OUTSIDE! I have to pay attention to tell if the compressor is even running, & I haven't seen any appreciable change in my electric bill. Go with the inverter!
Window units are designed to a price point and nothing else. Yes, they cool a space, but you pay a price, so to speak.
awd_maine
New member
I've been looking at something for my house, and have found this....http://www.caribouac.com/ I am all about doing my own stuff and this is the answer to me.
bazar01
Well-known member
No. The motor is 1 phase inveter duty rated AC induction or brushless motor.
Single phase AC input is converted to DC, then uses pwm within the inverter to generate AC output with varying frequency to control the motor/compressor speed.
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Trey T
Well-known member
^LoL.. I think you're confusing yourself.