Need Advice

I would like to try solar heating in the future. I currently use natural gas for space heating and water heating. I know my total gas consumption, but would like to be able to find out
how much each appliance consumes. Flow meters are too expensive.
Can I use the ir/motion sensor from a light to monitor when the flame on the water heater comes on? Can I use an old, 10 mhz, 286 computer to monitor the on/off cycle, or would a 120 mhz Pent. be better for this job? ( Future expansion for solar system controls possible ? ) Is there a better/best difference between using serial, parallel or game port? ( I cannot afford a $ 1,000.00 system for DAQ hardware and software from Omega.) Is software for this type of system available ( DOS, WIN or LIN ), or should I learn Q Basic and try to write my own DAQ software? Are there better options? Am I asking the right questions?
Tia
Cosmopolite
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This would be for hot water heating and not space heating, correct?

The *best* option is to get the manufacturer's data sheets for everything you have hooked up to the gas (you mentioned only water and space heating, so this should be easy). Each data sheet will give you typical gas comsumption figures. If you get the ratio of the two of them and divide this by your gas consumption, you can work out on paper how much gas each appliance is consuming.
If you need a bit more accuracy you could turn off everything other than the hot water for, say, a month; record how much this uses on your gas meter and subtract it from the previous period (month) when you have everything running.
The only other way to do it properly will be to install flowmeters and datalogging, but that will probably cost more than $1000 to do.
Hope this helps, Cameron:-)
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The flame fail safety device monitoring the pilot of gas fired appliances consists of a thermocouple that is wired in series to a simple solenoid consisting a small number of turns of heavy gauge wire. (Get a junked unit and take it apart.) The low voltage developed by the T/C drives enough current through the low resistance coil to hold the spring loaded valve in the open position. These T/Cs are readily available in appliance shops. If you connect one of these to a simple, home made, relay and insert it into your flame, you can have an on/off relay for under $5. Keep in mind, though, there are on and off time lags. That should be easy to accommodate in your calculations. A simple way of measuring time in service would be to let the relay control the power to an old style electric clock. They are excellent accumulators.
The cheapest solution that works reliably is ALWAYS the best. The relays works at 0.000 000 1 GHz. That is quite fast enough.
Walter.

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Walter Driedger wrote:

Wonderfull ! This sounds like what I am looking for. Will give it a try. Thank you for the info.
Cosmopolite

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