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[email protected]

OK. It's coming straight into the offseason. Time to make corrections & start planning to prevent this years mistakes next year.

My current project (besides hauling manure):

Single 24 VAC control valve (easy to find).

Thermostat. So "the brains" know when the temps are high.

Timer. To initiate temperature controlled irrigation intervals.

Which off the shelf devices do I need? Grainger, Home Depot, etc all have the thermostats. I sell the valves (Richdel 2400T). Radio Shack & Ramsey Electronics both offer low cost timers.

The idea here is to walk off to the real job every day knowing that if the cloches get too hot, a servo will open the vent. Likewise when the cloches are removed, the plants will get a short interval (10-30 seconds) burst of mister activity for as often as is required based on the duration & extent of the high temperature event.

The whole thing should be small enough to bundle & package in a weather proof box that is smaller than a breadbox. The componenets are worth less than $100.

Unless we're independently wealthy, retired, or otherwise unemployed, everyone who lives in a place where the daytime Summer high temperature could exceed 85 degrees F needs one of these devices. And we can't go buy one because there are none being made. Take my word for it.

I'm not interested in a windows based computer program. I know about those. Plenty out there for greenhouse operators. Too many good parameters. Absurd expense.

And we don't need a multi-station controller that costs $500 without any of the sensors either.

So now the question: How do I tie all this cheap, readilly available stuff all together to make it work? Any ideas?

Serious emails only! LOL

Steve

10/20/2003 11:00:15 AM

Brillion Wisconsin

Steve, Great ideas, I had a similar idea about a thermally controled cold frame. My idea was to use D.C. cooling fans like those used on copiers. The fans would turn on at a preset temperature. At night the same device could turn on a 100 watt light bulb for night time heating.

I repair copiers and get all kinds of fans, motors etc. for nothing. It would be fun and cheap to build one.

I never got around to it, too many other things to fix around the house.

I can see the arguement already....Honey what are you doing?.....Building a prototype smart pumpkin plant enclosure....then a few seconds for her to think about it....then pumle in the patch 3.

10/20/2003 12:01:07 PM

Kuna, Id.

Hmmm.....Steve I ran into the same problem this yr with controling the heat in my pkn house. By the way my pkn house is a 1973 full size Blazer with a ceramic heater(29.95) and some cheap (19.95) 2 fan window fans in each door. The fans have on/off settings and seem to be real close to what the temp was inside the Blazer. The plants are raised to window level so they dont get leggy. I could hold the temp at min of 80 and max hit 90 2 times and the plants got all the light they needed. While doing this I was tuning the green houses in the patch as to how big I needed to cut openings and when they needed closed to hold good temp during the night. As far as a misting sytem goes I use 2 timers(39.95 each) bought at Home Depot, each has six settings and I just hooked them into a "Y" built from pvc. I had 12 plants this yr. and over 400 misting heads at 7' off the ground. I could hold patch temps in the 90's even though we had over 17 days over 100. I can add more timers if needed. All this to lose all the plants to soil pathogens. So I just look at it as a few less things I have to work out for next yr. Now I just need to kill the bad crap in the soil.
Ken

10/20/2003 12:16:26 PM

[email protected]

The element of time is easy to manage, as both of you indicate. I also do this now with both a 9 zone Richdel hybrid controller & a Home Depot purchased Melnor controller with built in valve (about $50.00). The Melnor has a swift little misting function. But on cool days there is nothing to prevent it from coming on except on those days I hear the forecast before I leave & remember to shut the thing off. But an inaccurate forecast this year cost me 5 weeks of all male flowers in late June & all of July.

The challenge lies in opening the 24VAC power with a temperature controlled relay switch. <<Or in creating a voltage that is capable of driving a servo (probaly 9-12 VDC for servos)>> This will close the zone valve (by opening the supply voltage) based on input from the temperature sensing device that will then intermittantly open & close the 24VAC supply for as long as the temperature limit remains exceeded.

I already have an irrigation controller, so then in my own case the timing function of the controller may be left undisturbed. This since misting is rarely needed before let's say 11AM or after 4PM.

But now we're assuming the potenntial user has a contoller in place.

It might be more practical to scrap existing hardware & start fresh with an eye towards the greatest number of potential users.

Come on folks. Somebody out there has a bother-in-law or cousin that's an HVAC technician. Remember. The thermostat that controls our home HVAC system is also a 24VAC device just like an irrigation controller.

10/20/2003 12:59:03 PM

Deer Park WA

Tremor, I built exactly what you are describing only 110 volt. I used a single pole double throw remote bulb temperature controller (honeywell, but Penn Johnson will work) the temp range is adjustable from 40 degrees to 110. I installed the selonoid valve, temp controller, and cheapo appliance timer in a five gallon bucket with the hose connections piped through the sides and siliconed, as was the pig tail for the extension cord. I set the timer to come on between 9:00 am and 8:00 pm then set the remote bulb t-stat to 85 degrees with it wire tied under a nozzel. It works great for me I built two of them (patent Pending!).

10/20/2003 3:05:55 PM

Key West, FL

Gerry, what language is that? lol

10/20/2003 3:11:03 PM

Jackson Twp, Ohio

So basically what we need is an electronic switch between our irrigation timer and our valve. Or a temperature controller that would control the main valve? It might be easier to make the thermostat run a main irrigation valve. just my two cents worth. Time to get the heat gun and the old thermostat out.

Nick

10/20/2003 3:17:37 PM

[email protected]

Lord I forgot how much I hate shoveling cow dung. Rained over an inch yesterday. Darn near totaled the wanna-be truck. Lame Expedition platform Ford F-150 peice of *@#!!&@!! *hit excuse for a man's truck...What in God's name was I thinking.

Anyway. Now we're getting somewhere. Gad's. How often does the unit cycle? I was thinking ON for 30 seconds. OFF for around 120. Back & forth until the temps drop below threshold. Is that how it runs?

Maybe since you have it all worked out I should buy a completed unit right from you. So long as the patent is applied for & pending, I can't swipe it from you anyway.

What say?

Steve

10/20/2003 5:35:25 PM

Oz

steve,look in the phone book for ac/heat supply house.
draw up what your trying to do.
they will sell you the right stuff cheap.
tell them to keep it(thermal relay) simple and non powered if possible.
granger,,etc,,are expencive!!!
the ac supply houses are best.
trading a AG to a heat air guy is the cheapest!!
also..if you use a bellows type relay(mechanical) thats rated for 110volts ac/15ampsetc,,, you can run 24 volts across the contacts.that is if the relay is thermo mechanical,and doesnt need power to operate.
make sure your connections are tight...silicon grease keeps water out.even silicon adhesive.......

10/20/2003 6:35:14 PM

Bristol, ME ([email protected])

I took an old water conditioner timer head and modified that. It has a built in 24 vac solenoid which could be hooked up to a valve easily for use on city water or a well..The pins allow you to set it at 2 min intervals..I used the timer portion to turn the pump from the river on and off, running 4 min on, 30 min off, but it could be set to whatever you need. By bypassing the daily switch, it would run in cycle all day, I just unplugged it after temps cooled in the evening. I believe this could be adapted very easily to anyones needs. The heat in a cold frame can be accomplished with a 110v trailer thermostat inline with your heat source, i.e. light bulb, ceramic heater, etc. Throw in a couple of appliance timers and your automated. Just my 2 nickels..

10/20/2003 7:03:52 PM

ny

I have lots of green house temp controls, CO2, light and everything on the market that costs about what you marry together. Might want to check them out as it makes life easy, plus the 3 year warrantee a plus to protect your investment! It might help you out?

10/20/2003 9:20:16 PM

Wood River, Nebraska

Steve, get yourself a White Rogers digital thermostat and a remote temp sensor from Graingers. Use this to switch a 24v relay on say at 85 degrees for cooling and another one on for heating at 50 degrees. Now you can control a fan for cooling and a light bulb for heating in your hoop houses early season and a sprinkler valve for cooling later. Couple this to a cyclestat II and you can control the misting time and duration. I set mine for 15 seconds on every 15 minutes when ever the temp is above 85 degrees up until six pm. The thermostat has four program times so you can program a higher temp for night time to prevent misting in the evening and wet foliage.
dave=stewee

10/20/2003 10:10:12 PM

Deer Park WA

The thing is if you use a 24 volt system you have to throw a step down transformer into the mix. There is a battery powered (9-volt) selonoid valve that Rainbird sells but I can build two auto water buckets for the cost of one of those babies. Also the Water buckets can be used for simple auto irrigation. Tremor I can adjust the differential on the t-stats from two to ten degrees so the on/off time can be adjusted from 1 to five cycles per minute depending on where you place the remote bulb. Ben thats just engineering lingo from my energy management design/install days. I will fish my water buckets out of storage and post a few pictures. I have all the details in my video from last season.

10/20/2003 11:21:59 PM