Cool Graph of load and duty cycle on 4 ton AC at night

[SignatureSolarJames]

4 ton AC, day temp 94, night 78

ac temp 68

Just an anecdote

 

[Solarisium]

4 ton AC, day temp 94, night 78

ac temp 68

Just an anecdote

View attachment 152039

Would be even more interesting if you identify each axis, units, and each dataset on the chart.

 

[SignatureSolarJames]

Would be even more interesting if you identify each axis, units, and each dataset on the chart.

kW and Time

from 18k portal

 

[American-Thunder]

4 ton AC, day temp 94, night 78

ac temp 68

Just an anecdote

View attachment 152039

Hey James I am curious what brand/model of 4 ton AC are you using that its pulling under 2000 watts? I would also like to see a daytime graph as that appears to be overnight. I have a similar graph but when my 4 ton AC (with microair easystart) still ramps up and consumes roughly 3500 watts running and yours looks to be consuming much less. My system is about 10 years old and I have been researching an upgrade.

 

[400bird]

I was just thinking the same, my unit is a similar size and uses 3kW.

 

[Rusty959]

Would be even more interesting if you identify each axis, units, and each dataset on the chart.

 

[Zapper77]

Hey James I am curious what brand/model of 4 ton AC are you using that its pulling under 2000 watts? I would also like to see a daytime graph as that appears to be overnight. I have a similar graph but when my 4 ton AC (with microair easystart) still ramps up and consumes roughly 3500 watts running and yours looks to be consuming much less. My system is about 10 years old and I have been researching an upgrade.

My 10 year old economy 2 ton compressor pulls 1,500 watts. Plus another 400 watts for indoor blower.

Edit updated numbers. at night when the temperature drops and the pressure drops...my compressor pulls 1,200 watts

 

[42OhmsPA]

4 ton AC, day temp 94, night 78

ac temp 68

Just an anecdote

View attachment 152039

I'm assuming red is grid, is that correct?
What's up with the ripple on the right side and blips on the left side?

 

[Zapper77]

4 ton AC, day temp 94, night 78

ac temp 68

Just an anecdote

View attachment 152039

Two speed? SEER rating?

 

[Cheap 4-life]

Hey James I am curious what brand/model of 4 ton AC are you using that its pulling under 2000 watts? I would also like to see a daytime graph as that appears to be overnight. I have a similar graph but when my 4 ton AC (with microair easystart) still ramps up and consumes roughly 3500 watts running and yours looks to be consuming much less. My system is about 10 years old and I have been researching an upgrade.

I’m seeing two power supplies or two legs of the inverter each supplying roughly 2000w when AC is running

 

[Cheap 4-life]

I'm assuming red is grid, is that correct?
What's up with the ripple on the right side and blips on the left side?

I’d suspect its short duration backfeed to the grid before the inverter has time to react as loads shutoff

 

[wattmatters]

Here's our last 20 days of ducted AC:



Entering Winter here, so that's mainly for overnight heating. Even though we are now further into Winter, it's actually been warmer this last week, so not much heating needed.

What's more interesting with such systems is how much energy they consume when idle. e.g. this is ours yesterday when it was off the whole time:

 

[time2roll]

Is that cycling I see? When it gets hot mine just runs straight through to 5am. IIRC mine is 3ton pulls 2kW.

 

[wattmatters]

Is that cycling I see? When it gets hot mine just runs straight through to 5am. IIRC mine is 3ton pulls 2kW.

How much any heating or cooling system cycles power on/off depends on the thermal properties of the dwelling/space being heated/cooled, the temperature differential inside to out, the unit's output capacity relative to the space being heated/cooled and the type of controller. Some units are also capable of running at different power levels rather than simply on or off.

A well insulated and draft-proofed space will not usually require a heater/cooler to run continuously once the temperature set point is reached.

Indeed a system running continuously is a sign the building's (or room's) thermal properties could use some improvement.

Here's an example - back in March when we had a late Summer, here's a day where we put the ducted AC on late morning and it ran right through until about dinner time. Can see the power consumption varying through the day but it was pretty much always on. Our place is not great thermally, lots of air leaks and not particularly well insulated.

 

[Philip53]

My 10 year old 2 1/2 ton geothermal unit, pulls right at 2300 watts (on stage 1). Very hard to imagine a 4T unit pulling only 2K watts, even on stage 1 (if it is a 2 speed compressor). Does the data include the outside condenser unit draw as well? Something doesn't look right.

 

[Adam De Lay]

My 10 year old, 3.5 ton A/C takes just over 3kW to run, and that doesn’t include the air handler.

 

[American-Thunder]

My 10 year old, 3.5 ton A/C takes just over 3kW to run, and that doesn’t include the air handler.

Thats more in line with my 4 ton at 3500w not including the air handler. At night we just use mini splits in the bedrooms and air handler on circulate so I rarely see the big boy fire up at night. During the day I have the air handler fan on, mini splits on, and at 100 degrees the Central air will only cycle every 30-45 minutes. Thats the best way I've found to trim my usage here in southern AZ but I asked the original question of @SignatureSolarJames because I am considering replacing the central unit next winter.

 

[Rusty959]

Someone check my math, but for 4 tons of cooling performance to draw 2kW you'd need a SEER of 24.

This doesn't account for the air handler fan, etc. Additionally it looks like there was a base draw of ~500 watts which would mean the AC unit would be pulling even less. So I suspect this is a 2 stage being ran with the first stage only.

Regardless, I don't think that's the point of James posting this anyway, he's just showing off the reporting and a cool graph, not trying to prove anything about the 18kpv's performance. This isn't a big load for it as long as there's a soft start on it.

 

[Zapper77]

Someone check my math, but for 4 tons of cooling performance to draw 2kW you'd need a SEER of 24.

This is what I learned...it's time to upgrade my 12 SEER Air Conditioner.

 

[Zapper77]

My 10 year old 2 1/2 ton geothermal unit, pulls right at 2300 watts (on stage 1). Very hard to imagine a 4T unit pulling only 2K watts, even on stage 1 (if it is a 2 speed compressor). Does the data include the outside condenser unit draw as well? Something doesn't look right.

I'm surprised that your geothermal pulls 2K. Does that include inside air handler and does your geothermal also provide hot water?