Sanyo mini split AC (inverter/variable speed)

Dave Angelini

Re: Sanyo mini split AC (inverter/variable speed)

I use what I think he wants like you describe Rich. The bad part is it is not as elegant as your currnet limiting. It is a CC aux derived DC level and if the clouds are intense the pump system will go off. As we know the mini-splits do not have enough intelligence to know the solar is not at normal output (clouds) and the aux just keeps cycling the heat pump at full output. It does protect end of day but it is primative to what I ultimately want. This is the reason that I stay away from using higher BTU pumps as you can get into real trouble on batteries when the grid is not there. I would rather use a small high quality pump that can take being run at full output ( GOOD WARANTY) than risk the deep cycles a large pump could cause.

A smart grid heat pump that communicates with an inverter that knows it's minute by minute power limitations.

XRinger

Re: Sanyo mini split AC (inverter/variable speed)

The way the clouds come and go so quickly, I wonder if it would be such a good idea to be cycling a heat pump off-and-on so much..

I think we blogged about what you needed earlier. To protect battery banks, I would hack my remote control.
My 'Bank Saver' controller would, if in heating mode, would know when the clouds rolled in,
and would trick the remote into thinking the room had just gotten 5 degrees warmer.
The remote would send that info to the Sanyo, telling it to go into standby.

The remote sends an IR data burst every 5 minutes, or anytime a button is pressed.
If you bank had a good SOC, that 5 minutes shouldn't murder the bank too badly.
To get it to send the bust right away, you need a button-push.

I checked the remote's behavior by taking one downstairs (where it's 10 C)
I was watching for an IR burst. The display dropped from 21 to 17C, no burst..
It was too cold to wait 5 minutes!

Utana

Re: Sanyo mini split AC (inverter/variable speed)

Well we are taking the plunge with another mini-split. This one is the 12 ton LG model with a SEER of 26. Our A/C guy says LG is a good brand for these. It cost about the same as the Mitsubishi 12 ton we bought last year about this time. The install is going a bit slower. I've had to look up a lot of stuff on line to install the thing. The installation instructions are not as good with this thing as they were with the Mitsubishi. We're doing it the same as the last time - doing most of the install ourselves and calling an A/C guy to vacuum and hook up the lines. Finally about done with our part now, we need to hook up the electrical to our fuse box (waiting for an electrician friend to help with that), and do some tidying with the lines coming out of the house. Hopefully we can have our AC guy come out first of next week to get it all running. Yay!

Kelly

techntrek

Re: Sanyo mini split AC (inverter/variable speed)

I assume you mean 12,000 BTU (1 ton), and not 12 ton. Most homes only have 2-4 tons total. 8)

solar_dave

Re: Sanyo mini split AC (inverter/variable speed)

techntrek wrote: »

I assume you mean 12,000 BTU (1 ton), and not 12 ton. Most homes only have 2-4 tons total. 8)

Unless you live is AZ, from what I can gather from several source the most reliable my personal AC guy, they are now recommending about 3 tons per 1500 sq ft. I wish I had know about the mini splits when I replaced them a few years back, but I did get a good deal on a pair of Trane with 2 speed compressor. It helps the loads some and is way better than the old builder 10 seer Lennox units in every way.

I have a pair of 3 tons on the house and a 3 ton mini-split on the new building, Way over kill but I wanted the 3 wall units to zone it.

Dave Angelini

Re: Sanyo mini split AC (inverter/variable speed)

solar_dave wrote: »

Unless you live is AZ, from what I can gather from several source the most reliable my personal AC guy, they are now recommending about 3 tons per 1500 sq ft. I wish I had know about the mini splits when I replaced them a few years back, but I did get a good deal on a pair of Trane with 2 speed compressor. It helps the loads some and is way better than the old builder 10 seer Lennox units in every way.

I have a pair of 3 tons on the house and a 3 ton mini-split on the new building, Way over kill but I wanted the 3 wall units to zone it.

And this is what most of trades folk will do. It makes total sense if the goal is to cool down a previously unoccupied space quickly. When you tell them, what if I keep it from getting that hot, how much do I need? They will usually tell you then that you will use more energy. When you finally get them to open their minds up to different strategies they reach the tipping point and "get it"

SkiDoo55

Re: Sanyo mini split AC (inverter/variable speed)

Just a little info on A/C operation. Normally takes about 15-20 minutes of run time to start condensing moisture out and that is when the highest level of BTU thermal transfer takes place on the coil. If you don't get to that point (except for maybe in extremely dry climates <10%) humidity you will cool but it will be a damp cool.
Optimum would be the unit sized to just cool to Desired temperature with the A/C running continuously on your hottest day.

Will note that this would not necessarily be the best if off grid power.

With the inverter based mini-splits trying to keep them on low seems like the target.

solar_dave

Re: Sanyo mini split AC (inverter/variable speed)

SkiDoo55 wrote: »

Just a little info on A/C operation. Normally takes about 15-20 minutes of run time to start condensing moisture out and that is when the highest level of BTU thermal transfer takes place on the coil. If you don't get to that point (except for maybe in extremely dry climates <10%) humidity you will cool but it will be a damp cool.
Optimum would be the unit sized to just cool to Desired temperature with the A/C running continuously on your hottest day.

Will note that this would not necessarily be the best if off grid power.

With the inverter based mini-splits trying to keep them on low seems like the target.

Well I do know that even the big 3 ton Tranes run long on the hottest days when temps are near or above 115F, so I think the sizing is pretty right on. Those are the days when the consumption of power far out strips the solar output by 80 - 100%, thank goodness for net metering. The mini's not so much as I usually only run is on low or super quiet low (not auto) and only one zone with a 9000 BTU wall unit, but in any case is is usually pretty low humidity here. Not had a problem with it so far and I do see it still cycle the compressor on the TED data acquisition .

Edit: This week I have seen the Utility struggling with Voltage levels, so much so that the pair of Grid Tie inverters get kick off line and have to resync. Today it is 101F here.

Utana

Re: Sanyo mini split AC (inverter/variable speed)

HA! Yes, 1 ton. Thanks!

techntrek wrote: »

I assume you mean 12,000 BTU (1 ton), and not 12 ton. Most homes only have 2-4 tons total. 8)

Arkansasoffgrid

Re: Sanyo mini split AC (inverter/variable speed)

Whats the largest btu that is available for 115vac, in a inverter type heat pump?

XRinger

Re: Sanyo mini split AC (inverter/variable speed)

Arkansasoffgrid wrote: »

Whats the largest btu that is available for 115vac, in a inverter type heat pump?

The size will be limited by the maximum amps the basic 120v outlet can provide. Most are at 15A.
I don't think you will find anything higher than a 12,000 BTUh unit.

Here's some typical specs.

Model: LS122HE
Brand: LG
Cooling/heating capacity: 11,500 BTU
Input voltage: 115 V/60 Hz
Power: 10.5 A

BB.

Re: Sanyo mini split AC (inverter/variable speed)

I am locking this "old" thread. Any new discussions should be continued in this thread as the old thread is very long and has some now outdated information.

Mini Split update for Offgrid

-Bill