My Greenhouse FARM In the making!

[cmv]

A few links are broken way back in the beginning and halfway through the thread, here are the fixed ones:

scubadude's thread about visiting stores

scubadude's DIY skimmer thread

Thanks for taking the time to write all this up here and sharing it.

[scubadude]

Thanx CMV

Brian,
I just got done checking the temps tonite at 10:45pm , the two systems that I have w/ underground chillers/heaters, both systems are at 70 degrees and outside air temp in the GH is 50 degrees, Keep in mind though one system is about 450-500 gallons and has a 350watt heater as well as a 250 watt heater on it both of them running 24/7, and the other system is about 300 gallons and it has a 200 watt heater on it right now. Also for comparitive sakes my rock tub which has NO heaters or no underground chiller/heater on it just a pump circulating on a 300g rubber made is 66 degrees right now. From my assumption Im still lead to believe that the two systems that have u/ground insulation are also actually acting as a heater somewhat. Gimme some feedback guys on your thoughts.

[Lunchbucket]

do you think that low of a temp is hurtful to the inhabitants. i know i would be crapping if my tank got to even 75!!

Lunchbucket

[Reefs Rock]

Scubadude

You'll remember we had talked about this way back in February when we met. You found out I was coming to FL to buy land to build a GH and you told me you had just ordered your GH. We were both excited to get to know each other and brainstorm this adventure. Here are my thoughts on geo-thermal cooling units.

They are just that, cooling units. Nothing more. Here's why. At a depth of 4', I believe you are going to have a very stable temperature down in FL. For the sake of this discussion let's use 50 degrees F.

Now all summer long you are pumping, let's say 86 degree water into the geo units and your return water is, let's say 82 degrees, keeping your aquarium water at an acceptable 84 degrees. So, you are giving up 4 degrees of temp in the cooling units as the water cirulates through the cooling units.

Some people would have you believe that the ground around your underground pipes is going to hold some of that heat that's released into the ground. Not so! The mass of earth is so huge compared to your little geothermal units that the heat is dissapated nearly instantly into the netherworld where the grinches, gnomes and angleworms live. .

That's why it works so good as a cooling unit. If you will remember, I suggested shutoff and drain valves to turn it off in the winter months. As it's working right now, you are trying to heat 300' of underground area with an unlimited area to expel the heat.

My advice is to valve it off even if you can't drain it. Just heat the water in the GH containers. I think you will find an increase in temps, maybe not enough with the rather small amount of heater wattage you have trying to keep up with heat loss into the ground.

Sorry my good friend. But those are just my thoughts.

[BGDIVING]

Scubadude, tonight will be a good test to see if your getting a little Geo thermal heating out of your system, my guess is you are but probably only up to 70 degrees or so. Your rock tub is probably a good control to see how much heating your gettting of coarse the heaters probably help a little also.

I just did a 4:30 am temp check. I'm showing 30 to 33 degrees out in the open areas tonight. I'm burning some citranela bucket candels under my mango tree trying to keep the frost away. And I just went out to the garage and over rode the automatic therastat and manually set my heat for 72 degrees tonight didn't really want it go down to the programmed 68 degrees for a few hours before the lights come on cause I don't think it's going to warm up to fast in the morning. Hope your corals stay warm tonight Let us know how low your temps dip. I bet your rock tank dips down to about 61 tonight. Did you run your popane heater tonight?

[scubadude]

Date: 1-05-07
Time: 6:45 AM
Air Temp in GH: 45 Degrees
Geo Therm. Tanks: 68.5 Degrees
LR tank: 60 Degrees

Lunch Bucket,
I would have thought the same thing, but I will tell you that the softie tank doesnt seem to be affected by it too much. The SPS tank is seeming to tolerate it w/out any deaths but I do believe there are some species that dont like it. I have sold off or moved alot of corals that I was real worried about. Realize this is an experiment too, I need to see where my limits are and how they can be approached. So far what Im seeing is that temperature change isnt too terrible even as low as the temps Im getting as long as its done VERY slowly.

ReefsRock,
I think Im gonna disagree with ya bud! My LR tank should be proving that right now....I mean its at 60degrees and the Geo Thermal tanks are almost 10 degrees warmer! Ok so there is a 200w heater on one of the systems thats 300g but I guarantee you that heater does NOT have a heatup of 10 whole degrees

[eddie]

I've did alot of reading on ground source heat pumps recently.


if they could be made with water exchangers like a chiller that would be nice if I could afford around 3,500 per ton installed.

the ground source heat pump concentates the heat and cold & very efficantly heats & cools a house around 50% cheaper in power.

you might could put a tee on the input line to the radiator and put a container full of water next to it, put a submersable pump in the container tied to the tee on the input line ,put it on a timer or run it all the time to keep the radiator water going but still be detached from the frag tank .

if the tank was insulated it would probably stay at higher temps ,or mabey even just put a sheet of styro over the top at night to help a bit .


I plan to try a well source type exchanger so water volume & draining arnt a prob.
A large insulated container with a overflow that is slowly filled with water from my well ,containing coils of PEX tubing to pump vat water thru (the stuff they use for radiant floor heating)

this is way cheaper and easyer than installing ground loops for me & easyer to control.I got the idea from a diagram showing differant types of ground source heat pumps.

I've decided to turn my 14x16 attached greenhouse frame into a 14x16 closed in air conditioned indoor coral prop room.
on the south east wall outside it Im going to build 2 insulated 4x8 vats, Ill just build a frame around them that I can easly control the temps in.(any more than this in my area will take a lot more planning & investing I can still fit ALOT of frags in 2 vats that size)

acording to anthonys book he had a 600 a month gas bill in his greenhouse because he found temps are easyest to keep stable by ambiant air temp.

though its not cold as Pittsburg here in NC it is cold .under the liner in the 4x8 vat Im puting PEX tubing to connect to a gas water heater so it will be heated like radiant floor heating.at night Ill cover it with styro. (also some ebo jabbers)


I plan to use 2 400watt iwasakis over them 4-5 hours per day also winter times since it will be mainly sps frags in them .mabey I'll even just run them all day when its cold enough for heat also .(dont really know yet)

oh ...another pob i see with detaching the radiator even if the waters moving all the time if it stays cold long enough wont it kill stuff living in the water like bacteria or somthing & still be polluted if reused later?

[Reefs Rock]

scubadude

Hey Bud, it's OK for you to disagree with me. We are just brainstorming here.

I'm just trying to get you to realize that the reason your system works so good during the summer is the temperature difference between the water going to the thermal units (86 degrees approx) and the underground temperature at 4' of depth (I used 50 degrees in the above example) allows for greater temperature reduction in the return water to the system.

Lets say I'm way off on your underground temp and it really is 60 degrees (Which I truely doubt.) it is not going to raise your water temp because you are returning water in the 70 degree range. That's a phsycal impossibility, right? Your still fighting a cooling effect in your underground unit. Turn it off for one night. see what temps you get and report back.

[Reinhold]

I'd guess that your soil temp at four feet deep is much higher than 50 degrees. My guess is that the temp is more like 70 degrees.

Just as the water will lose heat in the summer to the surrounding dirt mass through the radiators, the water will GAIN heat from the dirt mass when the water temp is less than the dirt, thus the higher temp in your tanks than in the LR containers.

I would agree that some sort of isolation valve would be a good idea during the winter months, as you'll never be able to heat that much water, only to have it lose the heat in the radiators.

Perhaps you could limit the flow through the radiators into the tanks to just a trickle for top off and occasional water changes, while circulating the radiator system water through otherwise empty Rubbermaid tubs to keep it oxygenated, usable and clean.

[Reefs Rock]

Reinhold

You are correct. We are only guessing at the ground temps 4' under, all of us are guessing.

The only sure way to solve this is to find out the REAL temp of the ground at that depth. My guess would be that someone in the FL Aggriculture Dept of a University would know or the FL Farm Bureau. Somebody knows those temps. All discussion about it is pure conjecture until some possitive temps are known.

A well driller might be able to tell us the ground water temperature and that would be about the same temp as the ground.

I'm still felling that in FL in the winter the ground temps at 4' are closer to 60 or less than 70 degrees, especially when we are talking about night time air temps in the low forties and even in the thirties, as BGDIVING has pointed out. The earth atmosphere losses huge amounts of heat at night to outer space.

In fact for every 1000' of altitude the air temp drops 3 1/2 degrees. That's a fact I learned in flight school. Ask any pilot.

[Lunchbucket]

now this is getting complicated

i hear you scuba...it is cool to see the limits and what will actually happen if you don't heat much. nice info to see and know.

Lunchbucket

[beetlejuice]

More pics?

[H2OENG]

Hi all.
Whenever I recommend geo chiller to people, this is how I tell them to plumb it:
Run fresh water through the ground loop, inline pump, closed loop style. Run a bunch of PEX (containing closed loop water) coiled into sump or other heat exchanger. Tank water constantly flows through heat exchanger. Control cooling by turning on or off inline circulator pump to closed loop.
Scuba,
You could easily modify your ground loop to work this way, and save a ton on your elec. bill.
Your loop now, with heaters on, is still absorbing heat. It WILL give up heat, too, but only when the tank water is COLDER than the ground temp.
You can cut the inlet and outlet to the loop off and bush them down to 3/4" or so (install tees and plugs for further expansion) and hook up several hundred feet of PEX and an inline circ pump (like a mag 24). Put this PEX coil into a food barrel or trash can.
Now take the in / out plumbing to the tank and push the water through the barrel. Thermostat (same type used for chillers) controls the circ. pump- On in cooling, off when setpoint is met. You dont want the heaters running at the same time.
Also, insulate your plumbing with split foam tubing, and insulate the tank with styrofoam sheeting. It will help to maintain temp in hot and cold weather.
HTH,
Chris

[BGDIVING]

Scubadude how deep did you say your radiator system is? I'm under the impression you dug down 6 ft. The real quetion we need to figure out is - just how deep do you need to go to hit a stable temp? and my guess is your close to that depth if your at 6ft deep.

I just went out and tested my well water temp - 77.2 degrees! that would definatly do some Geo Thermo heating for you. When I tested the well water the pump had been running most of the day, the pump house is in the 60's so it's not picking up any heat from there, the out side air temp near the hose bib is in the 50's there is about a 10ft run from the pump to the hose bib though copper pipe which is all in the shade. The same didgital termameter shows my 170 in the house at 74, one of my 55's in the garage under 4 VHO's at 78.4 and a low lit tank in the garage at 73 so the thermater is reading fairly close to correct in those ranges. I do NOT know the dpth of my well.

If your ground temp is close to my well temp then you should be picking up some heating from your Geo Thermal system. The closer your descending water temp is to the ground temp the less efficiently the ground will work to change the temp of your tanks. If your ground temp is 74 degrees and your tank temp is 69 adding a heater (up to the temp of the ground) is not a total waste becuase your helping raise the tank temp a little and them when the water goes under ground it gets raised a little more before it comes back into your tanks. What you really have is your tanks are acting as radiators and they are trying to heat the green house using the Geo Thermal enery. Therefore maintaining Maximum water flow (with minimal suface disturbace) though your Geo Thermal system all night would be the best bet for maintaining temps up to what ever your ground temp is.

Reefs Rock there's no way our ground temp at 6ft or evan 4 ft would be as low as 50 Degrees or evan 60 degrees.

H2OENG using a heat exchanger on Scubadudes system would cost him a couple more degrees of both cooling and heating, his pipes are already acting as a heat exchanger with the earth and to use a 2nd heat exchanger with in a heat exchanger would be ineffiecent.

One other issue that has been brought up is I believe the earth is acting like a heat sink and the water scubadude is running through the system is affecting his ground temp although I don't know how long he can store heat in the ground. In the summer the ground water level is possibly high enough to make this system a more effcient radiator but very likely in the winter the ground water has dropped below his pipes and the earth is acting more as a heat sink so during the day he may be pipping warm water down to the ground to be stored and released later that night if green house temps during the day get up over ground temp other wise he will be gradually cooling the ground around the geo thermal system.

[scubadude]

You guys RAWK!

This is the kind of input I wanted! BGdiving I believe is right on the money though! Brian my depth ranges from 4.5 - 5' depth on the U/G radiators. I am mostly gonna side with BGdivings thoughts on the whole issue but there have been some great points brought up by everyone here!

[H2OENG]

his pipes are already acting as a heat exchanger with the earth

Right. If the ground is colder than the tank, it will absorb heat from the water. If the ground is warmer than the tank (77 degrees??) then it will give up heat to the water.
If you are getting 77 deg water out of the ground, then add an air coil to heat up the greenhouse, too. If this is the case, he could leave it this way.

to use a 2nd heat exchanger with in a heat exchanger would be ineffiecent.

Adding heat electrically, only to have it pulled out by the cold earth is wasteful and expensive. If the system cannot maintain the temp, then something needs tweaking, IMHO. I would want this sort of flexibility and control on my system anyway. I don't think you would lose or gain 2 degrees by adding an exchanger, and if so, its about 8 degrees out right now.

So the big question here is what temperature is the ground around his piping. Heat only flows from warm to cold, so this is what will determine whether his loop is adding or removing heat from the system.
You could get a piece of copper pipe about 1/2" x say 6-8' long. Cut the end 3" into strips, bend and solder it to a sharp point. Insert a thermocouple into the pipe and drive it to depth. Let it sit a few minutes and record the temp. This should give a good representation.
Regardless of all the current readings and ideas, insulating the whole system- tank, piping, exchanger barrel, etc. will help to maintain temp. Insulating against the heat of the greenhouse in the summer, or the lack of heat in the winter.
Its good to see all this data coming in and ideas flying. It makes us all smarter in the end.
Lets find that ground temp.
Chris

[Reefs Rock]

H2OENG

Lets find that ground temp.

This has been my point all along. I was using hypothetical figures to get a point across.

Without actual temp data we're all guessing as to what is happening.

The input has been interesting and will help me when I begin my GH in FL.

[BGDIVING]

Reefs Rock, Don't forget your a litle North of us so you could possibly have about 2 to 3 degrees cooler temps at the same ground level as we have which would make yours a more effiecent cooler but might put you just below crittical temp in the winter if you stayed connected, where as Scubadude may be able to use his Geo Thermal system to heat on cold nights. Speaking of cold nights I've got to go out and protect my mango tree again tonight looks like another cold one. This cold weather is going to really sweeten up the oranges evan if it's not so great for more tender things like Mango trees and corals.

Scubadude looks like we're going to have another night like last night Hope your corals stay warm. Do wonder if you'll have any cummative cooling with successive cold nights??? I've been venting a little warm air all day because of all my lights but I'm going out there right now and close things up tight and start preserving some heat for tonight!

[Reefs Rock]

BGDIVING

You are right about me being N of Scubadude but I'm not sure where you live in FL.

Of course you guys realize I'm in WI and not familiar yet with FL's temps. I'm just trying to add my thoughts of geothermal heating/cooling into the conversation based on my 40 years training as a pipefitter here in WI. Our frostline in winter is 3' so 4' up here is probably 34 degrees, BBRRRrrrrrrrrrrr. Get me to FL.

Anyway, this has been a fun discussion and has alerted me to some of the problems I'll be facing when I get started in FL. I always did tell scubadude he was going to be my guenie pig and I would learn from his experience. Thanks scuba bud.

[BGDIVING]

Reefs Rock One way we measure the frost line down here is by where you can grow mangos (a tropical fruit) at my latitude you can only grow them with in a couple miles of the gulf that's our frost line. actually we get 2 to 4 frosts a year here most winters but occasionally go a winter with out a frost. I'm about 25 miles north of Scubadude but a little closer to the Gulf so we're both sitting right along the frost line, which might put us just far enough south that we could possibly use simple Geo Thermal methods for heating as well as cooling but only if your going to allow your corals to get a lttle bit chilly or insullate well.

Scubadude - maybe if you ran your over flow from your tnks into your rock tank you'd get a couple more degrees warmer air temp in the winter in the green house and a we bit coooler in the summer. Of course that's asssuming ypur water quality in your rock tank will not mess up your coral tanks. just a thought.