Killing a watt

I did end up purchasing a kill-a-watt meter, so anyone who wants to borrow it let me know, I’ll have all I can investigate with it investigated pretty soon.

I did all the things we plug in in our apartment. Some usage:
Fridge – ~1kwh/day (~365 kWh/yr – not too bad for a fridge)

Massage chair – avg of 50 watts, though just using the ‘knead’ function in place is 30 watts, using the percussion function (my least favorite) is 90 watts. 10 minutes is a very long massage for me.

Microwave – ~1700 Watts! (but not used for very long at a time)

Toaster – ~800 watts (also short time of and infrequent usage)

I also investigated ghost loads – the microwave (even though the display isn’t on when it is off) draws a watt or two while plugged in, one lamp I have draws a fraction of a watt when off but plugged in (??), Gil’s iphone charger draws a watt or two if plugged in, even without the phone on it. The toaster, massage chair, and other lights do not draw any measurable power when plugged in but switched off.

I am happy about the massage chair. It was a hand-me-down gift from a friend, and it is lovely, but I worried about power use. Nice to know that it draws about the same as a couple of compact fluorescents, and I rarely use it for a full 10 minutes on a given day.

All together, I calculated that we use less than 2 kWh/day, just as at our old apartment where we were separately metered.

Common power includes the washer (~.3 kWh/load from the literature) and dryer (~2.5 kWh/load from the literature), a 13 watt bulb that comes on when it is dark (quite a span in the winter), hall lights (less than 100 watts total) that should only be on when someone is in the hall, but get left on (need to get the motion sensor switch for them), and a couple of pumps for the boiler (not sure on their size).

All together, about 1 load of wash is done per day, and slightly less than one dry per day, on average. Of that, about 3 loads of wash a week are our family’s, and one or two drys (I air-dry my personal laundry…lets just say not everyone in my family does). SO with the other common area stuff, thats probably about an extra 1kWh per day or so.

Considering that on my last bill, the average usage was 73 kWh/day, and we used about 3 kWh of that (give or take a kilowatt for common area stuff), I’d say I should get an electrician in and separately meter the units as soon as possible!


3 responses to “Killing a watt

  1. Yikes, at that usage differential, if you’re splitting the electrical bill equally now, it’s worth $540/year to you to get the units separately metered. Or… using a 7% discount rate, if you can get the units wired up for metering for less than about $7,500 all in, it’s worth it on purely economic grounds. Crazy.

  2. Actually, it’s much worse than that – I pay the entire electric bill now, and the rents are low enough I could probably charge the same rent when I have stopped paying tenants electric. January was a worst case scenario for many reasons, and electric use is never that high normally. It is still high enough to justify the separation. Especially as it won’t be anywhere near $7,500!

    Average usage (I have a year’s record) is ~50kWh/day; current rates are about 16 cents/ kWh. So if I take all the common electric use plus my family’s use as (generously) 10 kWh/day, I’m paying $192/month too much. That is $2304 per year. That is probably a significant fraction of the cost of the electrical work to separately meter. I could be pretty off if the pump for the heating system is taking way more than I think, but I’m guessing I’m not too off.

  3. I’m for the separate meter just on principle alone– I find people tend to be far more environmental when they are paying for their gluttony. or to be nicer about it– maybe they have no idea about much they are using…and the cost consequences.

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