@Ebt - comparisons y/o/y are worthless in the general sense especially when HVAC is involved. You have to correct for degree-days for starters, and then it gets more complicated as its not JUST degree-days, its ALSO cloud cover (which nobody has decent stats for you can use.)
If you want to try to validate that this thing "works" there is an easy way to do it. Turn off all non-reactive loads (incandescent lights, water heater, etc.) at the breaker panel so they cannot queer the results. Turn ON all your reactive loads (refer maybe, but the big one is the HVAC.) Go outside to the meter and using a STOPWATCH measure consumption in kWh recorded over a fixed time with the unit NOT plugged in, making sure you give it enough time to get a statistically-valid measurement for the percentage change you believe is in play (10x is a large enough oversample to be VERY confident, 5x is reasonably confident.) Then, with the HVAC still running, plug in the "magic" unit and do it again.
Here is why its important -- my current month consumption .vs. last year is absolutely flat. BUT, I KNOW the HVAC system is pulling almost-exactly 20% less power. Why? Because my utility company gives me consumption in kWh ON AN HOURLY BASIS and I have from my own control system both metering on many loads but also exact time in which things happen (e.g. HVAC is in "cool", and for how many seconds across a given time period.)
One very, very accurate such period is when I go to bed, because I intentionally drop the temperature of the house by 3 degrees. The unit has to run for about an hour and a half to do that, continually, assuming it starts at the daytime setpoint. Further, since I just went to bed there are no other loads beyond minor parasitic ones (e.g. the 2w that the line-powered smoke detectors consume and similar stuff) so it is ALL the HVAC plant. Well, all I have to do there to validate that indeed it is more efficient is look at the month PRIOR to when it was changed out on the hourly graph during that same hours as I go to bed roughly at the same time every night, find the single-hour spike and divide. 20%, and there's so little pollution of the data set that I'm absolutely SURE what I'm looking at. And my collected data from metering devices on my own matches EXACTLY, within reasonable instrument tolerance, what the utility gives me on those graphs. Thus I KNOW that KUB's data is correct.
OK, so why is last month's bill flat .vs. last YEAR, when the old system was there? Because that 20% delta was offset by other things, such as my kid doing a lot of climbing and trips with her b/f
and then she comes home and runs five loads of laundry, which hits BOTH heating water AND the dryer. That absorbed the ENTIRE HVAC change! If I HADN'T changed it I would have seen a LARGER bill this last month .vs. last year.
As another example, the DAILY usage here over the last month has a 100% range! Why? Because there are days that I was here alone, I took a shower but otherwise did not use the hot water heater (its gated on use) and didn't wash or dry clothing, nor run the dishwasher (which uses hot water, obviously.) Thus only the espresso machine, the computer rack which is always on and the HVAC were loads of materiality and it rained that day, so the HVAC load was much reduced. On the other hand three days earlier Sarah ran three loads of laundry, it was a cloudless, sunny day and I took TWO showers (I did a crap-ton of yardwork in the afternoon and got NASTY) plus ran the dishes and such on top of it. Even though my instrumentation says BOTH days had equal average outdoor temperatures one had DOUBLE the power consumption of the other!
If you can't control for these things
and without instrumentation at the sort of level I have here you can't then you have NO WAY to run a valid comparison. Instrumentation IS THE ONLY WAY.
@Supertruckertom -
Quote:
Are there any worthwhile devices for residential uses that would be installed such as whole house surge protection or slow start motor kits on AC heat pumps, well pumps or other large loads?
Just paid off a 4 ton York heat pump and I want it to last as long as possible.
Fall Service checkup is Scheduled for Thursday afternoon.
YES BUT.
First, a QUALITY whole-house surge suppressor installed AT THE PANEL is always worth it in a modern home. Why? Because damn near EVERYTHING has a DC power supply and a microprocessor, and the manufacturers go cheap on the margins in the power section because not doing so costs money. Siemens makes what is arguably the best split-phase (residential) units that are sold in the market today under their "First Surge" line. They have various models but the difference between "pretty good" and "excellent" is so small you're NUTS not to buy the FS140 unit (excellent.) This should be installed at the main panel. They claim you "should" use the top two breaker slots but the difference between top two and any of them is not large in terms of actual protection (there IS a difference in certain situations but we're talking about the extreme margins here -- mine isn't and I'm not concerned about that at all.) The science on this is a function of propagation and activation time as the busbar has low enough reactance to be a non-factor; in fact if the difference is more length left on the leads on the device or further down the busbar you're better off with the busbar as it has less reactance than the lead wires do -- not a big difference, but a difference.
As for a soft starter yes, those are useful too. MicroAir makes good ones; you have to buy them based on the horsepower (or tons in the case of an AC) of the motor in question. These are only useful in the case of an older-style non-modulating condenser outdoors (or a well pump which is a straight induction motor.)
Modulating condensers, which already use an inverter drive, are neither compatible with nor would they benefit from it.
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