Mother of all solar hot water heaters

[David HK]

Hello folks,

Progress on my batch solar water heater is going well. I will soon put up on this web site photos that show the construction from start to finish.

In the meantime can anyone help with this question. I would like to find some computer hardware and software that will enable me to constantly monitor the following:-

Ambient air temperature.

Relative humidity.

Water pipe temperature in the solar box.

Air temperature in the solar box.

Perhaps someone has experience in this. I have searched the Internet and can find a lot on the subject with prices ranging from expensive to make it yourself.

Any ideas and suggestion would be welcome.

Regards from a cool and slightly damp Hong Kong. By the way, Spring has arrived and my mango tree is in full blossom.

Dave HK

[zapmk]

Hi Dave,

Have you looked at the Dallas 1-wire devices.

and the 1-wire viewer. you can get free samples

on there web page. the neatest little devices

I have ever use.

I use the 1-wire devices to monitor  

and control my solar hot water panels

circulating pump, and a lot of other things two.

like monitoring my PV panels, Battery banks

wind gen, hot water circulating from the wood stove.

I probably have a more sophisticated system then most.

But if you like I could gave you a run down of my system.

I like to let my computer do most of the work.

Mike

[GaryGary]

Hi Dave,

I use the Onset Computer data loggers -- they are reliable, accurate, and easy to use.    

You could use the logger in the U12 family that does humidity + 3 temperatures.

To use these, you hook them up to your PC, and setup the logging interval you want and some other data.  Then you disconnect them from the computer, hook up the sensors, and let them log.  They will log for up to months on the internal batteries.  When you want to see the results, you hook up the computer, download the data from the logger to the PC, and do plots on the PC.  The Onset plotting software is very flexible.  To me, the only downside of this deal is its fairly pricy -- $120 for logger, $30 each for temp sensors, and $90(?) for software.

I have also heard good things about the one-wire system mentioned above, and they would be cheaper, but probably require a bit more work to get everything up and going.

I added this section on doing measurements on my site -- you might find something useful there:

http://www.builditsolar.com/References/Measurements/measurments.htm

Not sure exactly what your aim is for the measurements, but if you want to get the hot water energy the collector is producing, you will have to measure the water flow through the collector in addition to the items you mentioned -- see the blurb on measuring collector output and efficiency at the link above.

Looking forward to seeing your pictures.

Gary

[GaryGary]

Hi Mike,

That sounds like an interesting monitoring system.  Can you describe it in more detail?

Thanks,

Gary

[zapmk]

Hi Gary

I'll try and not make this not to long winded, Back several

years ago I started getting in to the house automation

thing, to control things around the house and it has

bloomed from there.

Baseically this is the software I'am using

HomeSeer home automation software www.homeseer.com

and a pluggin (addon)called McsTemp this pluggin is

what I use with the Dallas 1-wire devices,

you can use it to monitor/controll/

graft/log to a database.

I whent total electric with my house. So I installed

an electric hot water tank, a hot water airhandeler for heat,

4-4X10 hot water panel on the roof,and a Earth wood stove with a

hot water coil on the back, How comes the fun part.

Some of the 1-wire schematics I got from this site

www.hobby-boards.com they do have prebuilts and kits

for 1-wire devices but I chose to build my own.

For my heat and hot water I use the software and pluggin above

the Dallas DS18S20 for monitoring incoming and out going

water temp,for both roof panels and coil on wood stove

to control the pumps. To turn the off and on the pumps and

control the water flow I use some wireless Z-Wave relay switchs.

This is what I do for heat and hot water and it all

controlled by my computer.

If you would like more info on the PV panels logging ect.

or how I use the software and 1-wire for the wind gen.

Let me know, probable sould start a new thread on this.

Mike

[David HK]

Thanks Gary and Zap MK,

I am still moving forward and installing the distribution piping. Today (Friday) I take delivery of the double glazed glass panel covers for the solar box. Might have the kitchen on line early next week and the rest of the house by the end of the week.

Still have to lag the hot pipe after that and tidy up before finishing the project.

Am still working on the sensor aspect and note your comments with interest.

Dave