Monitoring energy use of a mini-split unit?
davidsmartin
| Posted in Energy Efficiency and Durability on
Can I install a kwh meter like this $14 one from China on ebay to measure how much power my new mini-split unit uses? The description says that it works up to 260VAC, up to 100 amps and measures both instantaneous usage (volts, amps, watts) and kw-hours. If it is this simple why doesn’t everyone do it?
http://www.ebay.com/itm/231602812752
Thanks,
Dave
GBA Detail Library
A collection of one thousand construction details organized by climate and house part
Search and download construction details
Replies
David,
What matters is accuracy and dependability. The one you link to is an unknown product from China.
Many energy nerds (including Marc Rosenbaum) favor utility-style kwh meters -- the round ones that have a glass front that are mounted on the outside of your house. You can buy used ones. Here are links to two possibilities:
GE meter, reconditioned, $35: http://www.infinigi.com/ge-kilowatt-hour-kwhr-reconditioned-utility-meter-with-ez-read-100a-p-5106.html?ref=99
Itron meter, remanufactured, $30: http://www.solarhome.org/itroncentrondigitalmetertypec1sfm2s240vcl200remfg.aspx?gclid=CjwKEAjw1f6vBRC7tLqO_aih5WISJAAE0CYwMD-0RvHagD_Vb4LQfHtzz5IZVppbx4B9B4R9SwkZWxoCA1fw_wcB
The reason everyone wouldn't do it, even if it is very simple, is that the vast, vast majority of the population doesn't really care and wouldn't know how to interpret the results.
Thanks to both of you. I asked the contractor who will install the system if he could also install a meter and he basically said that he did not know how. So I guess there has not been much demand.
Not sure about the $14 unit from eBay, but you could definitely use a monitor from Brultech. You don't need the builder to install it, you can do it yourself if you're willing to connect a wire or two to circuit breakers inside your panel.
An electrician should know how to install either the traditional electromechanical one or the cheap one you found. Code, or some interpretations thereof may prohibit an electrician from installing it it is not UL listed. That would be a good incentive to use the traditional meter, though an option might be for the electrician to provide a box where you install it.