What are the best options to measure the electricity usage of common area in a condo?

June 16, 2009 10:32 AM

What are the best options to measure the electricity usage of common area in a condo?

We installed 2 electric heaters in the crawl space below the house to help reduce humidity and alleviate problems we had with fungus forming on the wooden beams supporting the house. The electrician who did this hooked them up to the circuit of the owner of the 1st floor. Since this benefits all tenants we'd like to share the cost of this electricity. Which bring us to the problem of measuring it. We've contacted the power company about installing a new meter and then having an electrician hook the heaters to the new meter but I feel the cost of really too high (~1400 CAD total) compared to what we'll be measuring and splitting.

So does anybody knows of a better (and cheaper) way to do this?

The heaters aren't plugged on a socket so I can't use a device like a kill-a-watt. We'd also like the device to not lose track of power usage after a power outage. And it's a bonus if I don't have to go in the crawl space every 6 months to take a reading (but I'm willing to do it).

posted by coust to home & garden (8 comments total)

Since you can't use a socket, you can use something like an Electrisave that wraps around the electrical feed you want to measure. A list of a few more will let you comparison shop.
posted by fireoyster at 10:44 AM on June 16

What about getting a surplus meter and meter base, and having the electrician install these in the new circuit (between the breaker panel and the load)? With all the "smart meter" installs going on, there must be a ton of old analog meters available for cheap.

You'd have to read this meter yourselves and figure out, based on electricity rates, how much to kick in and give to the tenant whose bill is being charged for the heaters. But I would expect this to be a whole lot cheaper if you can keep the power company out of the project, and especially if you find and supply the parts yourselves.
posted by FishBike at 10:46 AM on June 16

How about just comparing the downstairs tenant's electricity bill from prior month's with the bill since the installation? Good faith assumption that they aren't now running three new dryers in their apartment... Take an average across a few months and call it good, with an understanding that you'll check in every once in a while to make sure they don't feel like they're getting the shaft.
posted by Pantengliopoli at 11:54 AM on June 16 [1 favorite]

months... damned apostrophes, flitting around.
posted by Pantengliopoli at 11:55 AM on June 16

You want an electric submeter. Don't get a whole separate metered line from the utility company when you can install a submeter on the circuit in question and read it yourself.
posted by Chris4d at 12:26 PM on June 16

BTW - depending on your budget, you can get submeters with separate wired/wireless panels for readings, and some even have software for tracking them on your computer.
posted by Chris4d at 12:29 PM on June 16

Make magazine has an in depth write up on this very subject in this months issue.
posted by thekiltedwonder at 1:48 PM on June 16

All you really have to do is count the time the heater is on for, which is a pretty simple little project. Installing a proper sub meter is probably a much better idea though.

Going the utility route is completely wrong. Aside from the high initial cost, there are a lot of monthly fixed fees. Easily $20 often more than $30 per month. The fixed fees are often hidden, places like "delivery charge" which appears to be usage based but is actually a blend of usage and fixed.

Don't add separate bills except where absolutely necessary. For example, you could save your tenants a lot of money by sub metering the units all off of one main feed. Of course there may be landlord tenant law considerations that make that kind of thing impractical...
posted by Chuckles at 3:02 PM on June 16