● sensor location	updates every 10 seconds	48 HOUR chart updates every 10 minutes hover mouse over chart to see details
4 - 4X8ft. Sun Earth collectors	COLLECTOR TEMP.	Heat exchanger pump:
Rheem 80 gal. water heater used as storage tank	STORAGE TEMP.
Bosch Aquastar AQ125-PLP-S	Chart shows propane tankless heater on/off cycles. Heater is: (turns on when solar tank drops below 120F and pump(s) are turned on)	Baseboard pump: Radiant floor pump:
My 2nd floor office/lab	2nd FLOOR OFFICE TEMP.
	OUTSIDE TEMP.
Things to notice: Sudden increases in the room temperature are due to my lighting the wood stove that has a heat reclaimer blower.  It is mounted in the flue above the stove as shown at right and it raises the room temperature by 5-10F in 10-20 minutes. The propane heater only operates if the storage temperature is below 140F, and it brings the temperature up to 140 to feed the radiant loops.  In the absence of solar gain the storage tank will settle out between 70 and 110°F.  110°F is the return temperature of the hot water from two baseboard radiators on the second floor, while 70° is the return temperature from the concrete radiant floor.  The collectors augment this base temperature when the sun is shining.  When you see the propane heater short cycling - that is when it is heating the 2nd floor via radiators, and the storage temperature typically will rise in steps each time it runs if it was below 110F. On sunny days you will see the room temperature rise in the late afternoon due to the direct solar gain of sunlight entering the west facing windows.  This effect can be significant in spring and fall.
I drain and fill the collectors seasonally since they would over heat in the summer.  If antifreeze gets too hot it will turn acidic and rot the copper pipes.  We have a long heating season in Maine and I fill after the first frost and drain once temperatures get above 40F consistently. DRAIN FILL 05/22/09 -- 05/03/10 -- 05/31/11 -- 05/33/12 10/05/12 05/29/13 10/12/13 06/01/14 10/20/14 06/29/15 10/16/15 06/01/16 10/08/17 06/14/17 09/01/17 06/14/18 10/04/18 06/24/19 10/11/19   10/05/20
I also monitor the solar domestic water heating system on my house, and the solar electric power generated by my solar array.  If you are an electronics geek like me, then you need to know about the technology behind this web page.  It is a device called an ioBridge that is designed to monitor and control things through the internet.  It is affordable and relatively easy to set up.  In order to monitor the AC and DC pumps on this page, I built my own interfaces to the ioBridge.  Here are the schematics for them.