Move whole-house AC or get a window AC unit?

[Redflyer]

I'm in a similar situation.

I have a 3 ton unit that runs our large bedroom suite. I bought a 1 ton window unit (my wife isn't too have with the look), and use it to supplement the 3 ton unit. The window unit is PV only and I run it all night. It helps the 3 ton central air quite a bit.

But I'm getting to the point of maybe taking the 3 ton unit off the grid and just powering it from PV. My problem is my PV daily input. I'm in the 33-40 kw per day range. The 3 ton unit runs about 22-25 by itself with no window unit 'help'.

This fall (after the summer heat), I'm going to replace my 400w panels with 450w panels....and add 3 more (7 vs 10). I think I'll have the daily PV input I need for next summer and will most likely pull the window unit for good. It became an experiment really.

And by the way, my 18kpv inverter easily starts and runs the 3 ton unit. Although I haven't tested that when the sun is down. But I have a pretty serious battery bank, so it should be good.

PS - I don't have any, but the Mini Splits look awesome.

 

[JRH]

I’ve been surprised how little fans cost in terms of incremental use on grid. Basically free.

Fans are your friends…they work wonders for reducing the need for a/c…plus listening to the has a calming effect…

 

[Supervstech]

Panama ENERGY STAR DC 54 inch with Remote Ceiling Fan

Panama ENERGY STAR DC 54 inch with Remote Ceiling Fan | Casablanca - Rich in history and tradition, the Panama is a true classic. Inspired by evolutions in the automobile industry, this product has been revamped and revitalized while keeping the foundation and integrity that makes it one of our...

www.hunterfan.com

Big momma 22w. But most people don't run them on high all the time. On medium/low most fans run about 15w. Of course Eggo's significant may keep them at maximum squeak/noise. Typically, around 15 watts on low, up to around 30 on high depending on the fan. It will move move air more efficiently at higher speeds, but usually you just want stir.

This fan, and their siblings are indeed energy sippers.

However, the vast majority of fans in homes are of the PSC, or shade pole variety… using considerably more watts.

I tried looking for specs on an average fan, and mysteriously I could only find the light bulb wattage spec…

 

[Supervstech]

A simple google search turned up average 1200Wh per day if run for only 8 hours a day… so… triple that for each fan run 24/7…

 

[Crowz]

All of those ceiling fan stats the companies claim look pretty and all but I do not see that in the real world. The hunter ceiling fans I have in my house count for about 150watts continuous on medium speed here. I have 2 of them going all the time pretty much so that 75 watts a fan at least.

I think they are 3 years old so not old fans either. But they count as part of my "constant load" to keep from worrying about accidental back feeding to the grid so I guess its worth it.

 

[Bluedog225]

This big b@stard runs at 3 watts to 100 watts. I use my 200 amp hour SOK and a Victron 12/1200. Runs all day without issue.

 

[Citlalatonac]

This big b@stard runs at 3 watts to 100 watts. I use my 200 amp hour SOK and a Victron 12/1200. Runs all day without issue.

View attachment 224239

That looks like a great option. Maybe a little pricey compared to a standard ceiling fan, but Hampton bay isn't moving 25,000 cfm for 100 wh. I'm going to strongly think about this and where it might fit. My main quibble would be using an LED puck that may or may not be replaceable in 10 years.

 

[Bluedog225]

Cheap compared to the big @ss fan. I call it my cheap @ss fan.

 

[glandpuck]

The thread is too long to read in entirety, but this is my 2 cents. A high efficiency condenser or heat pump like a Trane will have a very low LRA start up. Our 5 ton Trane LRA is 16 amps and the full running amps are 19 at 240 volts. So not much power needed.
Next, an attic fan is a big saver of electricity when it comes to running the AC and keeping the home cool.

The brand Quietcool is one of the best makers. Our models are all DC motors, variable speed and go on and off as needed when the attic temperature exceeds 75 degrees. Using DC motors makes them very energy efficient.

LASTLY, I SAW A VERY INTERESTING YOUTUBE VIDEO OF A PERSON HOOKING UP SOLAR PANELS TO AN ENPHASE MICROINVERTER AND THEN CONNECTING THE INVERTER TO THE CONTACTOR OF THE AC CONDENSOR. WHEN THE AC CONDENSOR TURNS ON, THE GRID CONNECTION LIGHTS UP THE MICROINVERTERS AND THUS THE SOLAR PANELS, OFFSETTING THE USE OF ELECTRICITY FROM THE GRID. WHEN THE CONDENSER IS OFF, NO MICROINVERTER POWER IS GENERATED. THIS COULD MAYBE WORK FOR YOU TOO.