Not my hot water exactly.
The technician who installed my thermal solar (hot water heater) unit had me buy a router (to the pleasure of my children with laptops who occasionally drop in). Then he ran a cable from the control panel of the unit and plugged it in. From there it sends data to an off site server and after he set me up an account, that is where I go via browser to monitor what it going on. The email was from the site notifying me it was ready to go.
December 2010 was the 11th coldest on record and we never had a temperature above freezing nor a sunny day for the first 15 days after installation. Finally we got a day with some midday sun and even with subfreezing ambient temperature I got some hot water production. See the graph of the first hot water I ever got from this unit. The area in red indicates water temperature rising in the storage tank. The yellow line shows the pump circulated antifreeze through the heat exchanger.
Since then we have still had below average temps and mostly cloudy days, but if we get a few hours of midday sun we are getting some water heated by the sun.
The solar crew showed up the day after the Amish crew finished the roof. It had snowed some so while two of them were working on installing the tank in the basement the third went up on the roof to clean off the snow to prepare for installing the racks that would hold the collectors.
My wife was talking on the phone and all of a sudden I heard her gasp and say, “Was that human? Something just fell off the roof!” We rushed to the window and sure enough, there was the guy tentatively getting up and brushing off some snow. He said he was fine and worked the rest of the day but I am sure he was sore the next day.
Here is the crew with some help from Janardhan who was here working on a different project getting one of the collectors up to the roof.
Here it is being installed on the rack.
Note the insulated flexible stainless steel pipe that the antifreeze circulates down to the tank through.
Even on cloudy days after a snow, within a few hours the snow melts off the collectors, so don’t let this picture scare you off.
Just that little bit of uncovered space at the top heats it up and soon the snow is in a heap at the base..
Even on a cloudy day with temps below freezing the fluid warms up, though not enough to effect heat gain unless one were to use an inordinate amount of water and pull a lot of ground temperature water into the tank.
I keep mentioning the tank which I just went down into the basement to take a picture of but although I can get to it to see the gauges my wife has the basement so stacked with boxes of gourds she is crafting that I can’t back up from it to get a decent picture.
It is larger and better insulated than a normal electric hot water heater. Unlike a regular hot water heater which has two heating elements one at the top and one at the bottom, the auxiliary heater elements in this one are at the top and in the middle. That keeps about the same amount of standby hot water available stratified at the top with cooler water at the bottom. As hot water is drawn off to be used the replacement water inlet is at the bottom.
The heat exchanger for the thermal collectors is in the bottom so it has a cooler water in which to work.
Whenever there is a 7 deg (4 C) differential between the fluid in the collectors and the water at the bottom of the heater the pump circulates the fluid.
We have the auxiliary heaters thermostat set to kick on to keep water at 120 F (49 C). Another of the features of the unit is that if the pump kicks on, the thermostat automatically rises to 135 F (57 C). This means it doesn’t turn on as quickly , allowing the solar collectors to take the lead in heating water. If the pump doesn’t run for 30 minutes, it resets to 120 F.
It also appears to turn off the axillary heaters at night, coming on again at 8 Am. This helps minimize off cycle standby losses.
I know it works, now all we need is some sunshine with warmer weather. We have reached the turning point of the winter. Statistically, the coldest days of the winter are January 18-20th here so the future looks bright.
When the collector is (eventually) really cranking, the temperature of the water in the storage tank can get quite high. They warned about bumping into the the external brass pieces like the drain valve as one could get burned. There is a mixer valve with the unit so the faucet temperature will never exceed 120 F (49C) so that will be safe.
120 degrees is, FYI, the “green” temperature they recommend even for conventional hot water heaters in order to conserve energy so check out your tap hot water temp and adjust it accordingly if you can.
It will be interesting to see how early in the spring we can start getting all our hot water from the sun.
” ‘I am the taste of water; I am the shining illumination of the sun and moon.’ Who has not seen the sunlight? Who has not seen the moonlight? Who has not tasted water? Then why do you say, ‘I have not seen God’? If you simply practice this bhakti-yoga, as soon as you taste water and feel satisfied you will think, “Oh, here is Krsna.” Immediately you will remember Krsna. As soon as you see the sunshine, you will remember, ‘Oh, here is Krsna.’ “
Journey of Self Discovery 6.3: Spiritual Advice to Businessmen