Energy Usage

Audrey Takes a Dip

Improving energy efficiency in the ol’ homestead is one reason Audrey exists. Living though summers in the Phoenix area, one thing to be conscious of is the amount of electricity it takes to cool the house. My local power company uses smart meters to help determine electricity usage. That plus a profile on what kind appliances you have can generate an energy usage profile which I show mine here. I strive to be efficient and how I use my resources is no exception. I have shown in example how I use Audrey to watch the climate in the house by managing the thermostats and ceiling fans based on scenarios and I am looking for other ways to improve that like using virtual machines instead of physical computers. One cost-saving feature for Audrey is around the pool pump. I know its further down on the list but common knowledge in Arizona says that you should run the pool pump one hour for every 10° of the daily high.   To further clarify, here is an example:

High temperature for the day is 110° / 10° = Pool pump should run for 11 hours

For most lazy Arizona pool owners, this means they’re overpaying for electricity and poolpump repairs because they let the damn thing run 11 hours every night, regardless. But since I have taught Audrey how to control the pool pump, she determines the high temperature for the day and then sets the length of time that the pump should should run. When I am feeling even more Scrooge-like, I even have Audrey shave an hour or two off the run times to save even more power reducing my carbon footprint even more without jeopardizing my crystal clear, blue watered cement pond.  I also added a SwitchLinc Relay to control the pool light to automatically for that cool nighttime ambiance that instills the oooh, and ahhs.

With these tips plus some additional things Audrey does for me, I have been able to reduce my electricity bill by 11% compared to the same time last year even though the cost of generating electricity has gone up. I hope to become even more efficient in the coming year.

How do you save the Benjamins around the house? 

Details for the Geeks

For the tech on how I did this, here are the ingredients:

After the switches were installed and added to Homeseer, I created an event that runs every night at 10pm (after the offpeak time starts) with the script below.  Basically it gets the high temperature for tomorrow, divides by 10, trims some more minutes to be a miser, and then sets a delayed action to turn it off at the new time.

Remember, I am not a professional coder by any means so edit for your own purposes and use at your own risk.

<div class="code">'=============================================================
' poolpump.txt
' Starts pool pump and sets end time to be tomorrow's high temp/degperhour - trim mins
' Lee Rogers 4:37 PM 2/17/2010
Sub Main
devcode = hs.GetDeviceCode("Outside Pool Pump")
strINIFileName = "weathercom_xml.ini"
degperhour = 10
intTrim = 90
intTemp = hs.GetINISetting ("Forecast","DayHi2","",strINIFileName)
strMinutes = ((intTemp / degperhour) * 60) - intTrim
strFullDate = dateadd("n",strMinutes,now())
strDate = formatdatetime(strFullDate,2)
strTime = formatdatetime(strFullDate,4)hs.SetDeviceStatus devcode, 2

hs.NewTimeEvent "Pool pump off (delayed action)", strTime, strDate, 1, 1, 1, 1, 1, 1, 1, devcode &amp; ":off", 1, "","Delayed Actions"

hs.writelog "Pool pump","High temp: " &amp; intTemp &amp; ", running for " &amp; (strMinutes / 60) &amp; " hours, off at " &amp; strDate &amp; " " &amp; strTime

End Sub


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