Sincere curious question...
What square footage does it cover and what does your average summertime electric bill run you and what are you paying per KW?
I've learned in my thread on our family vacation to Northern California next month (first time to that area) that the SF area really has some funky weather in the summer time and if I wear shorts I could freeze my butt off, which I found surprising.
In NC, heat pumps are a sizable portion of the market for good reason.
Upon rereading my post above, I think I should clarify that what meant was that I can't believe a 1976 AC is still alive and kicking. I am amazed that it is still in running condition. That is probably because we almost never use it.
Don't get me wrong, I would love to have a heat pump, though I worry about the heating capacity, as our 100,000BTU propane furnace can run for four hours straight first thing on cold winter (34F) mornings. That's a lot of heat from a heat pump. I have worked out our winter thermal losses, and I think that we need at least a 60kBTU heat pump, and probably more like an 80kBTU unit. We have no interest in splits both from an air filtration perspective and from a home layout that would require lots of heads. In general, the trend in Northern California is toward heat pumps since the climate is, in general, quite mild.
However, yes, we live in one of those funky microclimates. The old rancher who sold the land to the couple who built the house, insisted that they move the house site to where it is. I mentally thank him many, many times a year. The house is tucked into a hillside ravine with mature California Bay trees above us, and above them the top of the 2800' ridge to the west. The result is that the house is sheltered from almost all storms, and during the summertime there is almost always a downhill breeze that is significantly cooler (10-15F) than the top of the hill. The hilltop itself is usually ten degrees cooler than the city down the hill, so we get snow a handful of times a year despite being "in" the Bay Area. The couple's son bought a property across the street and put his home on top of a little knoll, where it gets baked in the summertime, and freezes in the winter. Their heating and power bill is about five times ours, despite pretty similar home construction. Unlike North Carolina, we have very dry air out here. So dry that I accidentally shocked the dog last night petting her.
We rarely run the AC, as in sometimes not for two or three years, unlike all of our neighbors. When we do, it tends to be for a week or two. Mainly either during wildfire smoke occurrences, or during heatwaves in August / September when we get hot winds out of the Central Valley with terrible air quality.
The house is a 1970s vintage 2,200sq. ft. building with an R-10 roof over two thirds of it (we couldn't add more when we redid the roof without enormous expense and permitting hassles), R-60 over the rest, R-15 in the walls, lots of windows with less than perfect seals that leak air. I would love to redo the window seals, but apparently nobody out here does it, and it isn't clear to me that I can do any better than just replacing the brush strips with new brush strips, and I think that won't do much for the air leaks. The replacement windows that we have been offered are less fire resistant, barring radiant films, so new windows aren't an obvious solution either, though I would love to find some.
So, with that preamble, peak power is $0.65/kWh, off peak $0.26/kWh. We installed 6kW of solar seven years ago, and it is fully amortized by our power savings. So, our "bills" are actually payments from the utility. To answer the underlying question, we use around 20kWh/day, or 600kWh/mo, which includes charging a plug in hybrid. We are net power exporters from March through October, and net exporters for the whole year. Two years ago, we added batteries for backup during outages, but they also enable us to store our off-peak solar power and run the house entirely off of our stored energy during peak times. We almost never buy peak power, even in the wintertime. All CFL/LED lighting, and not much in the way of electrical/electronic toys, or power draws. Base household load is ~0.2kW.
We are very fortunate, and grateful for that.
All the best,
Peter
