Hacker News Reader

Comment by js2 | Hacker News Reader

Over 4000 sq feet, three stories, mid-atlantic. I need to have an energy audit done though; it's still a lot.

That’s a _lot_. That would cost you 5k euro a year here! Do you have a good sense where it’s going? Unless there’s something obvious, you might want to get the meter checked.

It's the kind of figure that suggests someone has tapped the supply and has a cannabis farm next door.

8-9 tons of A/C split across three units. High ceilings. All windows, some of them quite large, are on the east and west side of the house. They are double-paned, but still. We have shutters but they are mostly open because we like the light. I work from home, and we home school our kids, so the house is always occupied.

We don't keep the house exceptionally cool. 78° during the day, 74° on the second floor at night just before bed.

I really need to try and track things down a bit better. I've got two sub-panels and it's a lot of circuits to track it down. I can start by monitoring the obvious things though: A/C units, refrigerators, dryer. I recently replaced two of the A/C units, but around the same time switch from natural gas dryer to electric and that seems to have been a wash.

Power comes from a nuclear plant less than 10 miles away, so at least it's clean? :-(

If I've done my math right on the A/C units, they pull a combined 8500 watts. It would only take them each running on average 15 minutes per hour to eat up 52 kWh per day.

Two 14 SEER units, one 3.5 ton, one 3 ton, and a 10 SEER 2 ton unit.

1 ton = 12,000 BTU.

(6.5 x 12000) / 14 + 2 x 12000 / 10 = 7971 watts.

The air handlers have 1/5 HP motors, call that another 150 watts per air handler, so we're up to 8500 watts at least.

52 kWh / 8.5 kW is a little over 6 hours, or 1/4 of the day.

To use less power and still have a comfortable home, I'd have to insulate it better and switch to smaller and more efficient A/C units. The units are sized properly according to:

https://asm-air.com/airconditioning/what-size-central-air-co...

Yeah, that seems entirely crazy to me.

I was like "That seems high" so I checked my usage meter and it say 112kWh. OK then. Then I notice it's set to monthly.

So that's about 4kWh per day. It will be a bunch more in winter, and your place is much bigger than mine, but still - that number seems kinda crazy huge to me.

That is awful.

Reply on news.ycombinator.com