Seersucker

This month I reached into the highest tiered rate, tier III. I really, really need to get to an R-34 insulation level in the attic and a split zone, SEER 17+ AC unit. This will significantly drop my usage.

Armed with a stopwatch, and knowing my bi-directional digital meter has a 1.0kH constant, I can count the pulses over a minute to calculate total kW draw. With the AC, both refrigerators, and both TVs, both DVRs and a game console on, I measured 100wH per minute...which calculates to a 6kW demand. With the AC off, it dropped to 21wH per minute, or 1.2kW.

My AC is pulling 4.8kW! No wonder my original 100A service panel caught fire during the 2006 heat storm.

I believe this to be a SEER 8 or 9 unit, and I know it's 4 ton. Let's assume it's a SEER 9, a $.12 kWh electricity rate, and a 4 ton unit (with one ton roughly 12,000BTu/h) at 48,000BTu/h, and it operates 1,000 hours a year:

48,000BTu/h * 1,000h * $.12kWh / 9BTu/Wh / 1000W/kW = $640 per year...total yearly load -- 5,333kWh.

Now, the above calc of 5,333 kWh doesn't match up with my own calculations (using 4.8kW over 1,000h, I'd use 4,800kWh) so there's an error in my estimated SEER or the tonnage. If I assume it's a SEER 10, then I'm dead on:

48,000BTu/h * 1,000h * $.12kWh / 10BTu/Wh / 1000W/kW = $576 per year...total yearly load -- 4,800kWh.

If I migrate up to a 17+ unit, I should expect to see:

48,000BTu/h * 1,000h * $.12kWh / 17BTu/Wh / 1000W/kW = $338 per year....total yearly load -- 2,823 kWh.

The difference (1,976 kWh) is 2/3rds as much as my entire PV array's yearly output! Again, it tells me that this should have been done first...I should have maximized energy efficiency and conservation before I bought into a PV array. Not only would I save cash I'd also live in a more comfortable house. My existing inefficient system is sucking money and energy away through an R-19 attic. I live in a SEER sucker.