Very old newbie.

Paul_L · 09-06-12, 04:35 PM

Hi everybody,

I just found this board today while doing a google search for a differential temperature controller. Google found Daox's diy design. Then I saw robaroni's introductory post from the Catskill Mountains and I figured I'd better join.

Over the last two years I've been installing a geothermal heat pump in my house. It's a 5000 sq ft ranch. I dug a 120' x 60' x 8' deep hole, watched it fill up with water and turn into mud, pumped the water out, dried out the mud, dumped in 6" of sand, thermally fused a ladder network of 6000 feet of 3/4" HDPE pipe with 300 feet of 3" HDPE header pipes, ran the headers into the basement and hooked them up to a pump and an 8 ton hydronic heat pump, installed a 120 gallon heat resorvoir tank on the output of the heat pump, jury rigged a temporary hookup to an air handler, and started it working in cooling mode in June.

Then I rested! (How's that for a run on sentence?)

Now I'm trying to devise a method of controlling this monster. I have found nothing on the market that is smart enough! Since I'm supposed to be an engineer,I decided to design one myself. Since I'm a very old engineer, I first tried to do it in using analog circuitry. That didn't work out, I couldn't make it smart enough. I am now resigned to doing it in a digital design, but I am too old. (Most engineers over 70 years old are automatically disqualified from doing digital designs.

) I'm trying to figure out how to selectively multiplex the outputs of eight temperature sensors into a microcontroller and then store the data. Then I can programmatically review the data and make logical decisions about running the heat pump.

It should be fun. I'm hoping to get some help here from Daox and robaroni, and maybe from some of the other resident geniuses.

I would be glad to post some pictures of a very big hole with a lot of mud in the bottom if someone will explain to me how to post pictures.

Paul_L

09-06-12, 04:35 PM	#1
Paul_L Old Physicist-Engineer Join Date: Sep 2012 Location: Dutchess County, NY Posts: 3 Thanks: 0 Thanked 0 Times in 0 Posts	Very old newbie. Hi everybody, I just found this board today while doing a google search for a differential temperature controller. Google found Daox's diy design. Then I saw robaroni's introductory post from the Catskill Mountains and I figured I'd better join. Over the last two years I've been installing a geothermal heat pump in my house. It's a 5000 sq ft ranch. I dug a 120' x 60' x 8' deep hole, watched it fill up with water and turn into mud, pumped the water out, dried out the mud, dumped in 6" of sand, thermally fused a ladder network of 6000 feet of 3/4" HDPE pipe with 300 feet of 3" HDPE header pipes, ran the headers into the basement and hooked them up to a pump and an 8 ton hydronic heat pump, installed a 120 gallon heat resorvoir tank on the output of the heat pump, jury rigged a temporary hookup to an air handler, and started it working in cooling mode in June. Then I rested! (How's that for a run on sentence?) Now I'm trying to devise a method of controlling this monster. I have found nothing on the market that is smart enough! Since I'm supposed to be an engineer,I decided to design one myself. Since I'm a very old engineer, I first tried to do it in using analog circuitry. That didn't work out, I couldn't make it smart enough. I am now resigned to doing it in a digital design, but I am too old. (Most engineers over 70 years old are automatically disqualified from doing digital designs.) I'm trying to figure out how to selectively multiplex the outputs of eight temperature sensors into a microcontroller and then store the data. Then I can programmatically review the data and make logical decisions about running the heat pump. It should be fun. I'm hoping to get some help here from Daox and robaroni, and maybe from some of the other resident geniuses. I would be glad to post some pictures of a very big hole with a lot of mud in the bottom if someone will explain to me how to post pictures. Paul_L