the first electric bill

[solarbird]

Just got the July electric bill. It covers June, including the record-shattering heat wave.

Remember, back in April we paid a buttload for a new furnace, new full-time whole-house MIRV 15 filtration, AND new ductwork partially for that but mostly for top-floor-only AC. (It's a separate ducting system, the old ductwork was designed exclusively for heat and wouldn't work for AC well at all.)

All this, just in time for the hottest June in history, the hottest days in history at all. 'Well timed there,' if I do say so myself. Regardless, it ran full time for days, and I've been thinking "well, it's worth it, but let's see how much it costs."

And now the bill is here. Our electric usage and bill last month was...

lower

...than last July or August, when we had the two usual room AC units set up, and no such thing as whole-house filtration.

Last July and August weren't even record-breakers. We had to run the room ACs pretty much full time anyway, because we had to have the house sealed up thanks to a horrible smoke season. We also ran the old furnace's fan full-time with good filters - not quite MIRV 15, but close - which helped a lot with the smoke, but not at all with the cooling.

And here we are, with a bill that's gone...

down.

And we never got above 26 (79F) in the uncooled part of the house last month, thanks to the top floor being cooled full time and with lots of circulation running. We couldn't've managed anything close to that with the old systems. This may've been an expensive experiment on my part, but holy fuck did it work out.

So after the Event, I knew it worked for cooling. Those little indoor wheelabout AC units with vent hoses are better than nothing, but they're still garbage, and the system we had put in is not. I was just afraid of how much more using it would turn out to cost, but turns out? That cost is less.

It still has another test to come, of course. Fire season, which started a few days ago. If we get a smoke event and have to seal up the house again, well, we'll see how it goes. But at this point, I'm feeling pretty confident. I think we'll be okay.

Holy hell, the bill went down.

Mind you, it's still one of those "It'll pay for itself in only... [calculates]... 375 years!" BUT STILL.

Down.

I gotta tell you, it's a relief.

Comments

[dewline]

Definitely an improvement there!

[solarbird]

HUGE improvement.

Not cheap. Ductwork isn't cheap, AC isn't cheap.

But fuck it's so much better.

[talkswithwind]

I'm so glad to hear that! Always a pleasure when something that makes your life easier to live ends up being cheaper in operating costs.

[solarbird]

Seriously. I thought it might cost more but I was willing to pay more - particularly for the filtration for smoke season. And I was hoping the better efficiency would cover the additional cooled area so it'd end up kind of a wash.

This though? This was a surprise. Just a good one, for once. xD

Wow, go you!

[kathmandu]

Good decision there. And the "pay for itself in x years" calculation has an insurance component--if the outside air quality gets really bad, or if virus gets into the house, and the very good air filtration and ventilation saves someone's lungs, that's a huge potential cost prevented.

Efficiency is said to be cheaper; it's nice when it really works out that way.

Re: Wow, go you!

[solarbird]

Oh of course, that line is mostly a joke. A one with halfassed/approximated numbers too, so don't take it too literally. It's based off a glance at some usage bars so. xD

[kevin_standlee]

That's impressive! We keep talking about having a home HVAC system put in, which would probably pay for itself more quickly given how expensive firewood in (even the energy logs), but it's still very expensive, and if we had to get a new power drop to bring us up to a full 200A service it would bring the cost somewhere heading toward $20K, which makes it a lot to swallow. So we just live with what we have for now and consider less expensive things like replacing windows and putting in more insulation.

[solarbird]

That sounds about right, I'm afraid. But do you really need 200A? This AC unit - which is a high efficiency heat pump really - is wired up to paired 20As at 240V, and pulling less than that at times.

Hell, the blower alone on the old heater was drawing 7A continuous in operation (and higher at startup), and the new one draws less than 1A, if obviously more at startup.

The efficiency on these things has improved a lot in the last 15-20 years is what I'm saying.

[kevin_standlee]

This is part of an overall issue with the house. We have only 125A service to the house, and there is clearly a power deficit on this house, to the extent that Lisa is thinking of putting in an either/or switch that would switch out the water heater to allow us to actually use the large clothes dryer we bought a decade ago. Lisa says that with everything we have here plus what we'd like to add means we should get the modern 200A service, but that also means replacing the main box and tackling the screwball way this house was wired. (She said that the two legs are not balanced properly. I leave the details to her and stand at a distance wearing insulated gloves in case I need to pull her off a live circuit in those rare cases she can't isolate the circuit.)

[armiphlage]

yay!

[solarbird]

Indeed.

[stickmaker]

Part of the savings are matters of scale. All other factors being equal, larger units tend to be more efficient (with modern technology the differences are minor, but still there).

Something else is probably having more impact, though. If the "little indoor wheelabout AC units" were 110 Volts and the new unit 220 Volts, well, there's a lot of increase in efficiency, right there. Again, all other factors being equal, higher voltage equipment operates more efficiently.

[solarbird]

Yeah, you know, these things. Little wheels, plug into a 120V outlet, have a hose to a mount in the window. Kinda trash, but, well, it's what we had.

(We can't use more standard window-mount AC units, we don't have the right kinds of windows.)

And yeah, we've gone from 120 to 240, so that's most likely part of it.

[hour_of_the_wolf]

Central systems are almost always more efficient.

What's on the boggling side is that you're usually better off over-sizing the system for the environment. You'll pay more up front for the capacity you won't use, but the efficiency curve means that the bigger system does less work.

In Michigan where we have actual weather throughout the year, it's not uncommon for our systems to be undersized, and we usually find that out late in the game.

[solarbird]

It's certainly appropriately sized - if not oversized - for the top floor. The problem is it couldn't use the pre-existing ductwork, because that was optimised completely for heating, which means it would cool very unevenly and very badly, particularly where such cooling is needed most, on the top floor.

(We have five levels. Garage and basement, ground floor, main floor, upper floor, attic which now has a floor so kind of counts as a level. Oh, and also a crawlspace which is on another level and is about... 3/4 height down to 1/3 height depending upon where you are. It's complicated.)

Garage/basement and attic have no service, of course, and neither does attic. Ground floor is between not underground and entirely underground depending upon where you are, and needs much less to no cooling and lots more heat. So the top floor and main floors are the two that need cooling, and really, it's the top floor that actually needs it for real.

Running new ductwork to the ceiling of the top floor from within the attic didn't require anything too complicated. Getting anything onto the main floor below that would require serious tearing into walls - EXCEPT for our stupid pointless useless UNTIL NOW two-storey entry, the ceiling of which is in fact the attic floor! so we could put a nice big duct to a grill there directly from the attic, spilling coolness down onto the main floor, and best of all, specifically the hottest part of the main floor.

It was an experiment but it sure as fuck worked out so yay :D