Aquaponics Digest - Fri 09/10/99




Message   1: Re: Evaporative cooling

             from Dan Settles 

Message   2: Re: pH Problems

             from Joy Pye-MacSwain 

Message   3: suscribe

             from Bertmcl

Message   4: Re: Evaporative cooling

             from "Barry Thomas" 

Message   5: Re: Evaporative cooling

             from 

Message   6: RCPT: Re: Evaporative cooling

             from 

Message   7: 

             from 

Message   8: RCPT:

             from 

Message   9: Re: RCPT:

             from S & S Aqua Farm 

Message  10: Re: RCPT:

             from 

Message  11: RCPT: Re: RCPT:

             from 

Message  12: 

             from 

Message  13: RCPT:

             from 

Message  14: Re: RCPT:

             from S & S Aqua Farm 

Message  15: 

             from 

Message  16: Re: Evaporative cooling

             from Ronald Polka 

Message  17: RCPT:

             from 

Message  18: Re:       Re: Evaporative cooling

             from "Barry Thomas" 

Message  19: Re: pH Problems

             from "William Brown" 

Message  20: Re:       Re: Evaporative cooling

             from 

Message  21: Re:       Re:       Re: Evaporative cooling

             from "Frank Stancato" 

Message  22: Fwd. New product requests

             from S & S Aqua Farm 

Message  23: Re: Evaporative cooling

             from "Barry Thomas" 

Message  24: Re: Evaporative cooling

             from "Barry Thomas" 

Message  25: Free Guide to Building a Cooler!!!!

             from Mike Strates 

Message  26: Re: Need off grid advice

             from "grizzly" 

Message  27: Re: Evaporative cooling

             from "grizzly" 

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| Message 1                                                           |

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Subject: Re: Evaporative cooling

From:    Dan Settles 

Date:    Fri, 10 Sep 1999 08:38:38 -0400

> Forgive what is probably a stupid question but as the main limiting factor

> in the effectiveness of evaporative coolers is the RH, why not use a

> dehumidifier or two? Especially in the more closed, possibly CO2 enriched

> GHs that Adriana and others were talking about recently.

If you add a dehumidifier it will increase the temperature more than the

few degrees you dropped it by using the evaporative cooler. The only way

to avoid this would be to remove the heat created by the dehumidifier

from the greenhouse.  The unit would then basically be an air

conditioner.  At that point you should just throw out the evaporative

cooler, turn on the air conditioner and watch the electric meter spin

rapidly.

Dan Settles

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| Message 2                                                           |

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Subject: Re: pH Problems

From:    Joy Pye-MacSwain 

Date:    Wed, 10 Sep 1980 10:18:48 -0300

Thanks Claude...... I just switched over to using potassium carbonate

yesterday....

I like the idea of  killing two birds with one stone.  Hummm... will check out

for root rot in the affected nodes, but I suspect that is not the whole problem

because one of the affected nodes only has three beds, half planted with

tomatoes

and otherwise is planted in lettuce. The tomato plants have only been in

that node

for half the time that they have been in the other two affected nodes.  The

lettuce

was only added two weeks ago.  I could possibly see root rot happening in the

older established nodes but not in this recently planted and only lightly

planted

node,

however at this point I am willing to look at any potential problem. Thanks for

your

thoughts.......

Joy

Claude Gelinas wrote:

> Potassium carbonate can be use as a substitute for your normal potassium

source

> and will increase pH.

>

> I'm not shure but pH drop can be caused by root mortality in hydroponic

system.

>

> Claude,

>

> --

>

>   Claude Gélinas Agr., D.T.A.

>   PHYTO Ressources

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| Message 4                                                           |

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Subject: Re: Evaporative cooling

From:    "Barry Thomas" 

Date:    Fri, 10 Sep 1999 14:52:39 +0100

Hi Dan,

> > Forgive what is probably a stupid question but as the main limiting

factor

> > in the effectiveness of evaporative coolers is the RH, why not use a

> > dehumidifier or two? Especially in the more closed, possibly CO2

enriched

> > GHs that Adriana and others were talking about recently.

>

>

> If you add a dehumidifier it will increase the temperature more than the

> few degrees you dropped it by using the evaporative cooler. The only way

> to avoid this would be to remove the heat created by the dehumidifier

> from the greenhouse.  The unit would then basically be an air

> conditioner.

Didn't want to take up too much bandwith on the list but it seems I went too

far and didn't say enough here.

I meant that only the 'cold end' of your dehumidifier should go inside the

greenhouse with the warm bits outside. So the dehumidifier should help lower

internal temps directly as well as indirectly via evap cooling(?).

Or is this what you meant by an air conditioner? I live in the UK -

knowledge of these devices is rarely a top priority.  :)

Also occurs to me that a reduced RH should increase transpiration. Might the

plants themselves not act as coolers? The energy to change the the state of

the water in the plants from liquid to gas must come from somewhere?

>  At that point you should just throw out the evaporative

> cooler, turn on the air conditioner and watch the electric meter spin

> rapidly.

More rapidly than when powering large exhaust fans? Also, the large volumes

of air use by fans must make any other form of atmosphere control (CO2

enrichment, filtration etc) very difficult. Might the

performance/reliability enhancements potentially available from a more

closed GH not offset the extra costs?

I'm not, in this or other posts, trying to say 'do it this way' or 'this is

the way things are'. I assume these ideas have already been thought of and

discarded. Just trying to understand why. :)

Barry

barrythomas@btinternet.com

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| Message 5                                                           |

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Subject: Re: Evaporative cooling

From:    

Date:    Fri, 10 Sep 1999 10:17:51 + 5 EST

Barry,

Just a thought.......

If your'e raising fish in your greenhouse (or even if you are not it might

work better for you).  I am a 

teacher in Upstate NY and we are trying to "kill two bidrds with one stone"

on the heating/cooling 

end of things.  If you are able to sink the "hot" end of the air conditioner

in a fish tank (large) you 

would be able to heat your water for fish growth and still benefit from the

cooling in the house.  This 

may be difficult and may not be the recommended way, but it works for us.

Just have to lengthen 

the lines on your AC unit.

Simply something we have tried with some success.  I don't think we are

talking on the same scale, 

however and would not recommend this until you speak with someone a bit more

qualified!

Mike

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| Message 7                                                           |

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Subject: 

From:    

Date:    Fri, 10 Sep 1999 10:24:22 + 5 EST

Hi All,

If ANYONE knows where I can get catfish (either shipped via air or by me

picking them up) in the 

Northeast (upstate NY - near Syracuse)  PLEASE PLEASE PLEASE let me know.

Our school year 

has just begun and we are as yet unsuccessful in locating some for our

students to raise in 

Aquaculture class.  Looking for fingerlings for our system, but any source

would be appreciated!

Mike Comet

mcomet@south-lewis.moric.org

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| Message 9                                                           |

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Subject: Re: RCPT:

From:    S & S Aqua Farm 

Date:    Fri, 10 Sep 1999 09:47:36 -0500

At 10:48 AM 09/10/1999 EST, you wrote:

>Confirmation of reading: your message -

>

>    Date:    10 Sep 99 10:24

>    To:       aquaponics@townsqr.com

>    Subject:  

>

>Was read at 10:48, 10 Sep 1999.

Mike - I get one of these messages for every one of your posts to the group.

Is it a setting in your computer that can be changed?  It's not critical,

but it does add to the volume I have to read.

Glad to see that your system is getting up and running, and I'm also glad

you're able to use the group.  Don't forget to change your subject line to

reflect the topic you're on.

Paula

S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775  417-256-5124

Web page  http://www.townsqr.com/snsaqua/

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| Message 10                                                          |

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Subject: Re: RCPT:

From:    

Date:    Fri, 10 Sep 1999 10:56:30 + 5 EST

Paula - will change that - never occurred to me - hope what I am about to do

works!

Thanks!

Mike

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| Message 14                                                          |

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Subject: Re: RCPT:

From:    S & S Aqua Farm 

Date:    Fri, 10 Sep 1999 11:08:39 -0500

Apologies to the group - so much for MY paying attention to headers.:)

Paula

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| Message 15                                                          |

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Subject: 

From:    

Date:    Fri, 10 Sep 1999 12:19:21 + 5 EST

Anyone know where I can get catfish for use in a recirc system here in

upstate ny?

mike

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| Message 16                                                          |

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Subject: Re: Evaporative cooling

From:    Ronald Polka 

Date:    Fri, 10 Sep 1999 10:25:25 -0600

At 02:52 PM 9/10/1999 +0100, Barry Thomas wrote:

>I meant that only the 'cold end' of your dehumidifier should go inside the

>greenhouse with the warm bits outside. So the dehumidifier should help lower

>internal temps directly as well as indirectly via evap cooling(?).

>

>Or is this what you meant by an air conditioner? I live in the UK -

>knowledge of these devices is rarely a top priority.  :)

>

>Also occurs to me that a reduced RH should increase transpiration. Might the

>plants themselves not act as coolers? The energy to change the the state of

>the water in the plants from liquid to gas must come from somewhere?

>

>

>More rapidly than when powering large exhaust fans? Also, the large volumes

>of air use by fans must make any other form of atmosphere control (CO2

>enrichment, filtration etc) very difficult. Might the

>performance/reliability enhancements potentially available from a more

>closed GH not offset the extra costs?

>

>I'm not, in this or other posts, trying to say 'do it this way' or 'this is

>the way things are'. I assume these ideas have already been thought of and

>discarded. Just trying to understand why. :)

>

>Barry

>barrythomas@btinternet.com

>

Barry 

        I will take a guess on this one but I believe the coefficient of

performance on a dehumidifier is not very good, it will not be a very

efficient use of  the electrical power. The bottom line here is to cool

economically. Dehumidifiers run on a refrigerant cycle which is inherently

inefficient if it is air coupled. The cost of running  a dehumidifier that

would be sized large enough is probably prohibitive. 

        The mass of air that typically moves through the greenhouse is quite

large. To give a numerical example I recently sized fans and evap cooling

for a commercial range that used gutter connected houses. The volume of

each 22' x 128' bay was 16,900 cfm (ft3/min). The air flow rate required

for cooling was 36,700 cfm, that is more than two air changes per minute.

The mass of the air moving through this greenhouse bay at the design

location is 2,300 lb per minute. This large mass transfer is what makes

cooling possible in the greenhouse. If evaporative cooling is not

pschyrometrically feasible due to high relative humidity than the mass of

the air movement through the greenhouse must be increased because the inlet

temperature cannot be decreased.

        Temperature control must always come before CO2 control because rapid temp

swings will cause more problems than reduced CO2. The primary reason for

CO2 enrichment is to restore depleted CO2 levels in a sealed greenhouse

that occur when the sun is shining and the house is cool enough so it

doesn't yet need venting. When photosynthesis causes the CO2 level to drop

to 100 ppm growth will nearly stop. CO2 enrichment enables high growth

rates when the greenhouse doesn't need venting. It can only be practical to

inject CO2 into a greenhouse during fan operation if a CO2 source exists on

site that is venting to the atmosphere already. These are specialized

conditions that the hobbyist never sees. This can occur when large

greenhouse ranges are paired with industrial processes or power plants, or

if the range is using geothermal energy for heat and the geothermal fluid

is stripped of its CO2 for corrosion control.

        What it really boils down to is if one is having problems with controlling

heat in a high humidity location in an existing stucture the most practical

solution is to size up the fans and move more air through the greenhouse.

Ron Polka

Southwest Technology Development Institute

New Mexico State University

Box 30001, Dept 3SOL

Las Cruces, NM  88003

rpolka@nmsu.edu

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| Message 18                                                          |

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Subject: Re:       Re: Evaporative cooling

From:    "Barry Thomas" 

Date:    Fri, 10 Sep 1999 18:24:39 +0100

Hi Mike,

If I gave the impression I have some big commercial operation, I'm sorry -

I haven't. My own small experimental system is Hydro only - no fish until

I'm totally confident about the plants.

I like your idea of moving the heat from the GH to the fishtank and agree it

should work better if heat loss from the tank happens somewhere other than

the GH though it might make things tricky during cold weather(?).

What kind of backup cooling do you have? I would find this 'hard' link

between GH and fish a little scary without some other way. What happens, for

instance, if during a time of unexpectedly hot weather, the fishtank temp

hits maximum and GH temps are still climbing? Boiled fish? Roast veg? Or

backup kicks in and saves the day?

How big is your GH compared to fishtank?

Just the thoughts of an amature...

Barry

barrythomas@btinternet.com

> Barry,

> Just a thought.......

>

> If your'e raising fish in your greenhouse (or even if you are not it might

work better for you).  I am a

> teacher in Upstate NY and we are trying to "kill two bidrds with one

stone" on the heating/cooling

> end of things.  If you are able to sink the "hot" end of the air

conditioner in a fish tank (large) you

> would be able to heat your water for fish growth and still benefit from

the cooling in the house.  This

> may be difficult and may not be the recommended way, but it works for us.

Just have to lengthen

> the lines on your AC unit.

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| Message 19                                                          |

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Subject: Re: pH Problems

From:    "William Brown" 

Date:    Fri, 10 Sep 1999 06:31:42 -1000

I use potassium silicate to adjust pH and found an interesting side affect.

The EC goes way up when adding extra potassium to the nutrient solution.  So

I would caution you to adjust EC/CF before adding extra potassium which has

a high electrical conductivity compared to other elements.

William Brown mahiwai@cmpmail.com

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| Message 20                                                          |

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Subject: Re:       Re: Evaporative cooling

From:    

Date:    Fri, 10 Sep 1999 14:29:45 + 5 EST

Ok - now i understand what we are talking about......

We are using our systems solely for heating our water for our fish.

Luckily, we have a refrigeration 

specialt's wife on our faculty here at school and get a lot of "gratis" work

done.  Our rig is as follows:

1.  If we need cold water for fish (trout, salmon, etc...) we put the "cold"

coil in the tank and put the 

"hot" coil in a 55 gallon plastic drum filled with water (more or less as a

heat sink).  The water that is in 

the drum is agitated by an airstone, so some evap cooling takes place.  When

the water in the drum 

gets too warm (110-125 degrees F) we open the drain on the bottom zand flush

it about 1/2 out - 

then refill the drum with cooler water.  Works great!  In fact, sometimes we

get a thin coat of ice on 

the tank water.  

2.  If we need warm water, we just switch the coils from tank to drum and

drum to tank.  This makes 

the drum "cold" and we don't have to worry about it if it freezes up too

much.  The "hot coil" is in the 

fish tank and works great - warms the water to the perfect tilapia and

tropical species temperature.

3.  This year's big experiment is to split the colis into two separate fish

tanks and run a cold culture 

(trout) in one tank and the warm coil for tilapia in another tank.  IN

THEORY (and we all know how 

that works...) it should swap heat and cold back and forth to do double

duty.  Time and a few dead 

fish will tell.

We have had awesome success with our aquaponics set-up.  We germinate and

harvest in about 

2/3 the time the seed packages say and have more pesto sauce from successful

basil growth than 

we know what to do with.  Also, although it may not be recommended, garlic

is going absolutely 

CRAZY in our nodes - can't stop it from growing although we had concerns

about root veggies 

rotting on us in such a moist environment.

In response, our greenhouse is not completed yet.  Our students raised

nearly $40,000 last year 

for this greenhouse and there dreams are now about to be built.  We are set

to begin construction 

of a 30X40 house in the near future.  

Sorry this is totally irrelevant to your needs - but other may appreciate

the info!

Mike

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| Message 21                                                          |

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Subject: Re:       Re:       Re: Evaporative cooling

From:    "Frank Stancato" 

Date:    Fri, 10 Sep 1999 14:59:23 -0400

Mike, sounds like a nice system. But unfortunately I am at a loss as to the

difference between the cold and hot coil? Could you please elaborate.

Thanks,

Frank

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| Message 22                                                          |

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Subject: Fwd. New product requests

From:    S & S Aqua Farm 

Date:    Fri, 10 Sep 1999 15:59:01 -0500

Adriana sent this to our address, but I believe it was meant to go to the

list.  Paula

-----------------------------

>Date: Fri, 10 Sep 1999 16:50:06 -0400

>From: Adriana Gutierrez & Dennis LaGatta 

>To: S & S Aqua Farm 

>Subject: New product requests

>

>Hi Gail,

>My smallest customer (and one of my favorites) has asked me to grow

>tsome special products for her and I have a few questions fromanybody

>who has experience with them.

>

>PEA SHOOTS (sprouts?) - I have not been able to locate any seeds for pea

>shoots and have never grown sprouts outside my kitchen.  Can you help me

>with:

>

>1.  Seed supplier - Johnny's and Ornamental Edibles don't carry them

>2.  How do you grow them and how long does it take?

>3.  Yield - how much seed is required to produce 1# of shoots?

>4.  What kind of special post-harvest handling is required?

>5.  Do you recommend any special peckaging?

>

>PURSLANE, SALAD BURNET, TREVISIO RADICCIO

>1.    Can these be broacast densly as you would salad mix or should the

>plants be  spaced farther apart?

>2.  Can you cut and come again?  How many cuttings before you have to

>re-seed?

>3.  How is it harvested - leaves, cuttings?

>4.  Any special handling requirements such as cold sensitivity?

>5.  Will they grow in our warmer climate - for the next 6 months our

>highs will be in the 80's.

>

>Any suggestions would be greatly appreciated.

>

>Adriana Gutierrez

>Green Cuisine

>Sarasota, Florida

>

S&S Aqua Farm, 8386 County Road 8820, West Plains, MO 65775  417-256-5124

Web page  http://www.townsqr.com/snsaqua/

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| Message 23                                                          |

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Subject: Re: Evaporative cooling

From:    "Barry Thomas" 

Date:    Fri, 10 Sep 1999 22:42:02 +0100

Hi Ron,

Many thanks for your detailed post - heaps of info there to think about.

A few things for the moment though...

> I will take a guess on this one but I believe the coefficient of

> performance on a dehumidifier is not very good, it will not be a very

> efficient use of  the electrical power. The bottom line here is to cool

> economically. Dehumidifiers run on a refrigerant cycle which is inherently

> inefficient if it is air coupled. The cost of running  a dehumidifier that

> would be sized large enough is probably prohibitive.

I'm sure you're right but a dehumidifier in a fairly closed GH would have

several effects: Direct lowering of air temperature. Reduced humidity

giving greater transpiration and reduction of some diseases/fungi/moulds

and (possibly) increasing the plants ability to cool themselves. Another,

which could be of importance in some regions, is that you should be

able to recover almost all the water that would normally be lost through

transpiration/evaporation - could be a significant saving if you have to

get all your water through eg an RO unit?

> The mass of air that typically moves through the greenhouse is quite

> large. To give a numerical example I recently sized fans and evap cooling

> for a commercial range that used gutter connected houses. The volume of

> each 22' x 128' bay was 16,900 cfm (ft3/min). The air flow rate required

> for cooling was 36,700 cfm, that is more than two air changes per minute.

> The mass of the air moving through this greenhouse bay at the design

> location is 2,300 lb per minute. This large mass transfer is what makes

> cooling possible in the greenhouse. If evaporative cooling is not

> pschyrometrically feasible due to high relative humidity than the mass of

> the air movement through the greenhouse must be increased because the

inlet

> temperature cannot be decreased.

So, in this example, you must push more than 60000 cubic metres

of air,  weighing over 60 tons through each bay of this GH per hour?

Sounds like fairly serious energy use. :) Especially when your plants

get tall enough to act as a baffle. Also, this much air must act as

quite a conveyor belt for pests...(?)

> Temperature control must always come before CO2 control because rapid temp

> swings will cause more problems than reduced CO2. The primary reason for

> CO2 enrichment is to restore depleted CO2 levels in a sealed greenhouse

> that occur when the sun is shining and the house is cool enough so it

> doesn't yet need venting. When photosynthesis causes the CO2 level to drop

> to 100 ppm growth will nearly stop. CO2 enrichment enables high growth

> rates when the greenhouse doesn't need venting. It can only be practical

to

> inject CO2 into a greenhouse during fan operation if a CO2 source exists

on

> site that is venting to the atmosphere already.

But that was the point I was trying (badly) to make. Increasing the CO2

level

is almost impossible in a GH that must have this kind of throughput of air.

If

you were able to greatly reduce this throughput, enhancements like this

become available - increasing yield and system viability.

> These are specialized

> conditions that the hobbyist never sees. This can occur when large

> greenhouse ranges are paired with industrial processes or power plants, or

> if the range is using geothermal energy for heat and the geothermal fluid

> is stripped of its CO2 for corrosion control.

I would _really_ like to see a system like this. :)

> What it really boils down to is if one is having problems with controlling

> heat in a high humidity location in an existing stucture the most

practical

> solution is to size up the fans and move more air through the greenhouse.

Again, I wouldn't argue with you. It just seemed to me that if an

alternative

method of cooling could be used, the amount of air flowing through the house

may be reduced to the level actually required by the plants. Maybe low

enough for some level of filtration at the inlet (probably a bit much to

expect

a bacterial filter but something insect proof so you're not, say, wafting

clouds of aphids over your plants) combined with a slight positive internal

pressure would increase security against pests. Also, any predators added

to the house are more likely to stay there and be waiting for those which do

make it inside.

At the exhaust, further water recovery could take place.

Is it not possible that all these (plus several more I'm sure I've missed)

potential gains may outweigh the costs?

I know there are a lot of ifs and maybes in all this but if only ever looked

at what is possible now...

Thanks again,

Barry

barrythomas@btinternet.co

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| Message 24                                                          |

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Subject: Re: Evaporative cooling

From:    "Barry Thomas" 

Date:    Sat, 11 Sep 1999 01:03:29 +0100

Hi Mike,

> Sorry this is totally irrelevant to your needs - but other may appreciate the info! Actually, this could be exactly what is needed. How does this sound: A while back there was talk on the list of using a long piece of water-filled tubing formed into two 'coils' for cooling. One coil was distributed around the inside of the GH, the other buried in the ground. The water was pumped around the tubing, transferring heat from greenhouse to ground. One problem with this is that the ground often isn't a good heat sink. Maybe your idea could be applied to this? If you altered things so that you kept the loop inside the GH and had a large tank of water outside, the two could be bridged using the kind of heat pump you describe. The cold coil is placed in a small tank inserted into the large GH loop and the hot coil in the large external tank. During the day, heat is transferred from GH to tank. At night, the hot water in the tank could be wasted or, if needed, an additional heat pump connected the other way around could transfer heat back into the GH. Ron pointed out that air-coupled refrigeration wasn't very efficient. This way, at least one side is liquid-coupled, could this raise efficiency enough to be worthwhile? It seems possible that the large GH loop could be kept at a lower temp than would be possible using the ground as a sink, maybe even low enough for condensation to form? Might be able to arrange things so that you get a dehumidifier / water recovery from the same hardware? Does this sound viable to you? Ron or others? Thanks for the info and good luck with your project - though what you've all achieved so far makes me think you probably won't need it. :) Barry barrythomas@btinternet.com .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. | Message 25 | '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' Subject: Free Guide to Building a Cooler!!!! From: Mike Strates Date: Sat, 11 Sep 1999 11:34:24 +1000 On Fri, Sep 10, 1999 at 02:59:23PM -0400, Frank Stancato wrote: > Mike, sounds like a nice system. But unfortunately I am at a loss as to the > difference between the cold and hot coil? Could you please elaborate. I beleive he is talking about a slightly more complex version of an external evaporative heat exchanger. These devices, as I've explained to fellow greenhouse lovers numerous times are great -- because they DON'T add moisture to the greenhouse atmosphere and don't need a lot of moisture to work properly. In fact, they TAKE moisture from the greenhouse -- the little droplets of water form on the heat exchanger coil and eventually drip into the pond. Mike's Passive Evaporative Cooler ********************************* Copyright (C) 1999, Mike Strates FOR THE SOLE USE OF THOSE ON THE AQUAPONICS EMAIL LIST This evaporative cooler is designed to be based OUTSIDE of the greenhouse, with only the tubing for the heat exchanger and maybe the overflow pipe going in. As such, this cooler does NOT add any humidity to the greenhouse and functions quite well. It can lower the greenhouse temperature by around 15F. Materials Required ================== * 1x 44gal drum/barrel (or similar) * supply of running, cool mains pressure water * 1x large (around 5') length of PVC pipe * lots of flexible garden hose * 12 volt car fuel pump or other external well-washed pump * 1x garden hose inline T-connector with flow control valves * 1x garden hose inline control valve/tap * power supply to run the pump * drill * silicone sealant or equivilant Overflows and Clean Pipe ======================== The barrel has TWO overflows. Drill one overflow (call it the TOP overflow) one foot from the barrel's top on the side of the barrel. Drill the second overflow around 1/2 a foot lower than the TOP overflow. Hence, you will have your TOP overflow and your BOTTOM overflow. You'll also need your CLEAN PIPE. Drill your clean valve as close to the bottom of the barrel as you can without damaging it. All three holes which you have drilled for both the TOP and BOTTOM overflows, plus the CLEAN PIPE must be just large enough to accomodate a small length of garden hose. Water Inlet Tube ================ A hole must be drilled in the CENTER or close to that of the barrel on the top lid of it. This hole should be just large enough to accomodate a 5' high length of PVC pipe. Insert this piece of pipe, ensuring it protrudes around 1' inside of the barrel and glue in place. There should be a 4' high statue protruding from the lid. Once dried, drill some small holes around six inches from the top of the actual piece of pipe to allow air to flow into the pipe. Just drill some holes all around, but don't go overboard. Then, its time to fix up the end cap. Drill a hole into the middle of the end cap, just large enough for a length of garden hose. You shall use this later on in the text. What We've Acheived =================== Right now, you should have a barrel sitting up next to you with around 4' of PVC pipe protruding from its lid, with some holes around the sides of the piece of pipe around six feet from its top. The sides of the barrel should have TWO overflow holes, realitively close to the top of the barrel, and ONE drain hole, very close to the bottom. You should also have a PVC end cap on the ground near you with a hole large enough to accomodate a length of garden hose in it. The Pump Assembley ================== You'll need your well-washed 12 volt fuel pump, or an external pond pump now. Using a length of garden hose long enough to reach to the pump's INLET (if you stuff up, and cut too short of a length, use a garden hose joiner). Glue one end of the pipe into the BOTTOM overflow (the SECOND overflow from the top). Once dry, run the opposite end to the pump. The Water Inlet Assembley ========================= >From your hardware store, you'll need a garden hose T-connector WITH control valves. These only cost around $2.95. You'll need to glue a length of garden hose into the PVC end cap you made, only around 2' long. Once the end cap has dried, press it onto the top of the large PVC tube you have protruding from the top of the barrel. Connect the end with only one connector of the T-connector (ie: the end opposite the |_|) to the piece of garden hose coming out of the end cap. Then, run a length of garden hose to one of the connectors on the T to a nearby water tap, but don't turn on the water yet or muck around with the valve on the connector. We'll discuss this later. The TOP Overflow Pipe ===================== The top overflow pipe will drip out water very slowly under normal operation. You can place a length of garden hose here and direct this flow anywhere you'd like, as long as it is lower than the barrel.. for this reason, you may like to put this barrel on a roof or on stilts. The DRAIN Pipe ============== Buy a garden hose control valve (just an inline tap for garden hoses) from a garden or hardware store. Affix a length of garden hose to the DRAIN HOLE we made eariler at the very bottom of the barrel, and then to the inline tap. You can then run a hose from the tap/valve to a nearby drain or just let it fall on the earth. The Pump Outlet/Heat Exchanger ============================== Next, connect a length of tubing to the pump's OUTLET and direct it in a coil like fashion into your greenhose for cooling. Bring the other end of the pipe back and connect it to the SECOND T on the connector which goes up to the large PVC tube and set its valve on the connector to FULL FLOW. Additional Aeration =================== If you want better performance, you can add additional airstones into the barrel. This is beyond the scope of this document. Getting it ALL Working ====================== Once everything is dry, set the valve on the T-connector which goes from the mains water tap to the large tube to FULLY OFF/CLOSED. The second valve which goes from the greenhouse's heat exchanger should be set to FULLY ON/OPEN. Go cautiously to the mains water tap, and give it a turn and make sure that everything holds water while it is off. Then go over to the valve on the T-connector and slowly turn it FULLY ON so that the barrel fills. Once water begins to spew from the TOP overflow turn the pump ON, and reduce the amount of fresh water going into the barrel using the T-connector's valve until just a small trickle comes from the TOP overflow. Measure the temperature of the barrels's water with a thermometer and check it one hour later. You should also see fine water droplets condensing on the tubing inside of the greenhouse. Congratulations, you're done! -- Mike "Skyfox" Strates ; www.croftj.net/~mstrates Voice: (011) 613-9440-5778; Voicemail (US): 1-888-392-4832, ext: 2913058153 ICQ #47663425 "... and while you're at it, why not treat the pax to some zero G's. Just knock the yoke right down the stoppers with one hand, and after you've made a perfect recovery, advise all on board that this terrible mishap was a result of clear air turbulence" -- Mike's 101 Never-Fail Ways to get fired from United. .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. | Message 26 | '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' Subject: Re: Need off grid advice From: "grizzly" Date: Fri, 10 Sep 1999 22:33:35 -0400 Hey are you related to Joe Nasmeth .------ ------ ------ ------ ------ ------ ------ ------ ------ ------. | Message 27 | '------ ------ ------ ------ ------ ------ ------ ------ ------ ------' Subject: Re: Evaporative cooling From: "grizzly" Date: Fri, 10 Sep 1999 23:34:03 -0400 Hi,I have a few ideas on this subject,first on your shade cloth,if you will leave a space between the cloth and your poly it will reduce heat gain thru convection. Second,instead of using misters inside your greenhouse,run the misters inside the dead air space between layers of poly,that way you can cool the air around your greenhouse without increasing the humidity,the heat inside the greenhouse will transfer to the cooler air inside the dead air space,be sure to place vents at the lowest and highest points on the outside layer of plastic only.Third,you can place misters above your shade cloth,evaporation will cool the surrounding air.I just had another thought,I have read many times about someones Poly being better,because it sheds water,which inhibits light penetration,but so does shade cloth,I wonder if you used a system like i'm suggesting,would you even need shade cloth? Opinions welcomed. Griz

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