H2O-cooled heat exchanger: design, setup & use (ex., IceBox)

[spurr]

An ICmag member and I were discussing that we have seen very few posts about setup and use, and the effectiveness (or lack thereof) of h2o-cooled heat exchanger (radiator).

The most commonly known brand is HydroInnovations, makers of "IceBox" (link to product page). So I wrote I would start a thread and post up pics of how I use IceBox(es) and what water chiller I use, pumps, etc. Also, my experience with the setup so far, and its effectiveness.

IceBox:
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A great intro into cooling a garden is the Featured Article by our very own Lazyman[1]. If Lazyman doesn't mind, I will link to his article here; it's a great intro into this topic that I don't think I could have written better. H2o-cooled heat exchangers (ex., IceBox) can be used to cool air from an air-cooled reflector, or to cool the hot air from the lamp, and the heat from the room, in place of an air conditioner.

In my case, even when outside temps are > 95'F, and I have 1,400-1,600 watt of HID with two < 1,000 watt ballasts running at midday, as well as fans and dehumidifier, in my grow room, one water chiller and two IceBoxes keep the canopy temp at ~75-78'F in day and ~68-70'F at night. My grow is a closed-room setup; no vent or intake from outside.

[1] "Keepin' it cool, man!"
by Lazyman
https://www.icmag.com/viewarticle.php?articleid=1477&page=1
​

.
Necessary BTU of cooling power; i.e., "what size water chiller should I buy?":

A 1,000w HID (ex., HPS) will put out ~4,000 BTU (3,500 btu of lamp heat and about 500 btu of radiant heat); according to HydroInnovatoins and/or WaterCooledGardens[2]. To use water cooled lamp(s) via Ice Box correctly, you need to add up all the BTU from your lamp(s). Ex., to cool only the lamp heat from the air-cooled reflector, the total BTU for the lamp(s) should be less than 90% of the BTU from the chiller (ideally < 85%).

Examples:

• (lamp BTU/chiller BTU)100 = percent of 'extra' cooling BTUs from the chiller with respect to room BTU of heat, if under 100.
• (chiller BTU)0.9 = max 'usable' cooling BTU from chiller, 90% of the total BTU from the chiller.
• lamp BTU/0.9 = needed BTU from chiller to cool lamp with an 10% 'extra' BTU for cooling left over.

If a grower wants to use the Ice Box to cool the room and the lamp heat they need to add up all BTU in the room (ex., lamp(s), ballas(s), fans, dehui, etc.). Then they need to use a chiller that offers greater BTU of cooling than the total BTU put out by the room. The total BTU for the room should be equal to, or less than, 85% of the BTU from the chiller, ideally. Ex., if one has 7,246 BTU of heat from a grow room, one would need at least 8,525 BTUs of cooling from the water chiller.

Examples of math:

• (room BTU/chiller BTU)100 = percent of 'extra' cooling BTUs from the chiller with respect to room BTU of heat, if under 100.
• (chiller BTU)0.85 = max 'usable' cooling BTU from chiller, 85% of the total BTU from the chiller.
• room BTU/0.85 = needed BTU from chiller to cool room and lamp(s) with an 10% 'extra' BTU for cooling left over.

If a grower is trying to use the chiller as an A/C unit, as well as to cool the heat from the lamp (like I do), they need sufficient BTU output (from chiller) over room BTU input; or less BTU input (from room).

[2] "Size Matters – How to Properly Size a Chiller"
Wednesday, October 27th, 2010
http://watercooledgardens.com/blog/?p=177
​

When horsepower (HP) doesn't equate to British Thermal Units (BTU) of cooling power:

There is an oft repeated claim that '1/4 HP water chiller is all that is needed for a 1,000w HID'; I believe HydroInnovations is the source of that claim, which they now try to distancing themselves from. Many growers believed that claim, then went out and bought any water chiller that was rated for 1/4 HP (ex. black EcoPlus model). Once they setup the water chiller and IceBoxes, they realized the water chiller could not keep the water in the reservoir cold enough, and many growers then labeled h2o-cooled heat exchange setups as bunk. However, the system itself isn't bunk, the problem was/is an under-sized water chiller.

The problem of under-sized water chillers is due to how water chillers are reported; by HP and BTU of cooling power. For mid-range brands of water chillers, the HP reported does not equal the BTU it should equal. Ideally, one HP of cooling is equal to 1 ton, which is equal to 12,000 BTU of cooling. But many water chiller brands and models do not provide 12,000 BTU at 1 HP. For example, the 1 HP EcoPlus water chillers do not provide true 1 HP worth of cooling BTUs; the white model (I use) provides 8,525 BTU of cooling, not 12,000 BTU.

Of all the commonly used water chillers, the best is probably ChillKing (and most accurate to 'true' HP worth of BTUs; ex., 1 HP is at least 12,000 BTU) and the worst is probably the (older) black EcoPlus. The black EcoPlus chillers are notorious for having low BTU per HP; ex., the 1/4 HP black EcoPlus chiller produces far less than 3,000 BTU of cooling power. The (newer) white commercial models from EcoPlus are much better and offer higher BTU than the older black models; but even the white ones pale in BTU compared to ChillKings ...


A few words about water pumps:

For the pump to be used for the water chiller, contact the manufacturer, or check the label/directions, for the suggested pump size (by gallon per hour (GPH)). A pump too large can damage the water chiller and cool the water less well than an ideal sized pump.

The pump used for the IceBoxes (or other heat exchangers) should have a 'max head lift' at least a few feet greater than the highest point (vertically) the pump will have to move water on the way to the IceBox. Ex., the water hose running from my water rez to the IceBox has a max height of ~7 feet, so the 'max head lift' of the water pump should be at least 10-12 feet.

The water pump I use for my IceBoxes is from EcoPlus (ECO-2254), it has a max head lift of 16 feet, and GPH of 2245. It is strong enough to move water effectively through two IceBoxes on two different reflectors.

'Max head lift' isn't the only criteria by which to purchase a water pump for the IceBox(es). Also important is GPH, higher is normally better, but 'too high' (GPH) can become over-kill too and reduce the cooling efficiency of the setup.

The Danner water pump brand has been suggested to me as a good and solid brand, more so than EcoPlus. I haven't had any problems with my EcoPlus pumps, ever, but I do think they are a bit 'low end'.

To sum up:

(1) Before buying a water chiller figure out the cooling BTU's you will need, via the BTU produced in your room (the help line at HydroInnovations and WaterCooledGardens are very helpful in this regard).

(2) Make sure to find out the BTU of cooling power from the water chiller, and make sure the BTU cooling is above the BTU produced in the room (according to the examples above).


Notes:

(1) The water chiller will have to be placed outside/away from the grow room; to vent the hot air produced while cooling the water.

I have my water chiller in a spare closet in my bedroom, it's directly across from the water reservoir in the grow room closet (both closets share a common-wall). I vent the hot air from my bedroom to the outside, because it has never been in the grow room so it doesn't smell.


Next Post: equipment recommendations and what lease to buy ...

 

[spurr]

Below are the tools I use, along with how I have everything setup:

IceBoxes:

• 8" for the 8" BlockBuster
• 6" for the 6" SS II

Thermostat for fans to cool room to specific day and night temp

• IceBox thermostat (slows/speeds fan to cool room or cool room less well)

water chiller:

• EcoPlus 1 HP white commercial unit (8,525 BTU of cooling power)

water pump for water chiller:

• EcoPlus ECO-1056 (1,056 GPH)

water pump for IceBoxes:

• EcoPlus ECO-2245 (2,245 GPH; 16' max head lift)

water hose (for chiller and IceBoxes):

• 1/2" Inside Diameter (I.D.) soft hose

water reservoir:

• 35 gallon trash bin (plastic), filled with 30 gallon of water; only like $16 instead of ~$60 for 50-55 gallons. I would prefer a larger rez, 50-55 gallons, and I would prefer to insulate it well.

Below are some pics of my setup, I use "ProGrip" rope ratchet light hangers. It allows to me lift the fan and reflector at the same time, and keep the reflector level. That is important for my setup, because I have the 8" inline fan connected directly to the reflector, both hanging inside the 5'x5' tent. I do not close the the tent 'door' because the SS II reflector hangs partially outside the tent.

I have both the IceBoxes setup to vent the cool air right back into the tent, the cool air does not get vented from the tent, on purpose. I also have a 4" vent fan setup in the inside, top, corner of the tent, to remove hot air from the tent.

I have two IceBoxes piggy-backed together, off of one water pump and one water chiller. This is good because it increases the cooling ability of the setup; two heat exchangers cooling air is better than just one.

Carbon-ish scurbber and fan for 6" SS II and 6" IceBox:

Vent fan for tent:

Next post: 'bits and pieces' needed to tie everything together

 

[krunchbubble]

damn interesting, props to you......

 

[spurr]

High kruch, nice to have ya' here!

I am going to make a few more posts to get out all the info I need to present. But I hope you feel free to ask any questions or give me suggestions, in the meanwhile, or afterward.

 

[spurr]

Fitting 1/2" I.D. hose over 3/4" male connectors ...


There are many ways to skin this cat, and I chose the easiest and least expensive, but it's still safe works very well.

The male connectors on the IceBoxes take 1/2" I.D. hose. To attach the hose to those connectors I use two hose clamps; tightened very well. I push as much hose (lengthwise) over the male connectors as possible, then attach the hose clamps.

I try to use two hose clamps whenever possible, but many times I could only use one.

In the first two pics below you will see 1/2" I.D. (5/8" O.D.) clear hose(s), connected to (black) 3/4" to 1/2" 'setup down' rubber adapter connector(s) used for indoor laundry mahcines and/or dishwashers. They are easy to find at a place like HomeDepot, or better yet, a local mom-and-pop plumbing supply store. The 1/2" I.D. hose is connected to the 'step down' adapter via (gray) 1/2" 'connector' (1/2" hollow tube). Hose clamps are used to tighten all connections.

The first two pics were taken downward and to the right, so please consider that when looking at them.

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The following picture is of the same connection setup, as above, but this is to the bigger water pump:

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The picture below is of connecting 1/2" I.D. clear hose directory to 1/2" male connector on the smaller water pump:

​

 

[spurr]

A tip to get the hose over the male connectors: heat up a cup of water until it's very hot, then soak the end of the hose for a couple of minutes in the hot water before pushing it over the male connector. That not only makes it easier to get the hose on the male connector, but it also makes a more secure/tight connection.

 

[krunchbubble]

sry, didn't mean to post in the middle of your discussion.....

next time, you might want make the first 4-5 posts in a row, then go back and edit them with what you want to say. so all your info is together.....

 

[spurr]

Okay, now we have it all setup, lets get it going!


Dew Point:

"...the temperature at which air must be cooled at constant pressure in order for it to become saturated with respect to a plane surface of water"
-As defined in Atmospheric Science: An Introductory Survey by Wallace & Hobbs

• The above quote was taken from the good web page: "What exactly is the dew point?" (link)

The water chiller I use, the white commercial model from EcoPlus, 1 HP, seems to have a factory-set temperature differential of 3 degrees; and it can lower rez temps to below 40'F. So theoretically I could set the water chiller to make the rez 50'F, and the room could get cooled very well and very quickly. And in fact I did just that, and once the rez temp was at and below 61'F lots of condensation would build up on the radiator (Icebox) and drip on the plants.

The build up and excessive condensation is due to the "dew point" of the room. The dew point, for our use case, I think can be explained as the temperature of an object at which point it will form condensation (or have condensation formed upon it) when the room temperature is X (ex., high) and RH is Y (ex., high). What that means, is if a hose has very cold water running though it, and the air temp and RH is high, condensation (dew) will form on the hose.

For my room, with RH of 55-60% and temp of 75-78'F, the dew point is below 62'F. That means if the rez water temp is < 62'F lots of water droplets will form on the hose, IceBox and rez tank, then drip all over (some) plant(s) and get sprayed on close wall(s) from the radiator air movement.

Below is a great dew point calculator, you enter the RH and temp of your room, and the solution is the dew point. The dew point, again for our use case, is a specific temperature of water, when running through the water hoses and IceBoxes, will cause will formation of condensation on water hoses, IceBoxes and rez, at room temp X and humidity Y:

• Dew Point Calculator http://www.dpcalc.org/

A general rule is to keep the water temp at (or around) 65'F to stay above the dew point of most rooms.


Setting the temperature for the water in the rez:

If a grower is only using the system to cool air from reflectors, then chilling the water to about 10'F below ambient temps (goal canopy temp) is a good place to start. Getting the rez temp ideal takes a little practice, but the 10 degree guide is a good place to start.

If a grower is using the setup to cool the room and the air from the reflector, instead of A/C, then at least 15'F below goal canopy temp is a good place to start.

I keep my rez temp set to 62'F or 63'F (I'm still working on perfecting the setting), which means the rez temp stays at ~63-65'F. I would like a bigger rez, and I would like to insulate it, that way it will stay cooler more easily.



Fire ...

Having so much water and electricity so close scares me, so I wanted some protection. Besides setting the max temp control for my Sentential 'Master Digital Timer' at 86'F, and using GFCI grounded outlets, I have setup two automated fire extinguishers ("Flame Defender") that go off when temps exceed 155'F. The fire extinguishers are rated for A, B & C type fires. Pic of the unit inside my tent is below:

 

[spurr]

sry, didn't mean to post in the middle of your discussion.....

next time, you might want make the first 4-5 posts in a row, then go back and edit them with what you want to say. so all your info is together.....

Oh, it's not like that. I didn't care one bit you posted, my bad if it seemed otherwise. I was just saying hello, that's all.

 

[BlueHaze]

1)Your water chiller is in another room?
2)I had an assumption that those unit work more efficient when you put them outdoor?
Very nice setup indeed.

 

[spurr]

1)Your water chiller is in another room?
2)I had an assumption that those unit work more efficient when you put them outdoor?

Yes, it's in another room. And yup, most of the time a water chiller goes outside. But in my case I need stealth, which is half the reason I bought the setup. I can cool my room, better than with A/C, and my outdoor A/C isn't running in the middle of the night* (when it's cool outside and there is not reason to use one).

The water chiller is also stealth because I don't vent from my grow room, so no worries about nosy neighbors (and I have a few!). I add Co2 to my grow and the only venting from my grow is from my bedroom. That is where hot air from the water chiller is vented, directly outside because it doesn't smell; it has never been in my grow room.

Besides stealth, the water-cooled system cools the room so much better than A/C. And the RH isn't stolen as it is from A/C; when using this setup.

Ideally I would have the water chiller outside, but for now I need stealth and how I configured everything gives me that in spades.

* with this setup I can run lights on in the day, when outdoor temps are > 95'F, and the room stays cooler than the rest of the house under central A/C. So with A/C I need to run my lamps at night, but with this setup I can run them in the day; which is much more convenient for me.
​

Very nice setup indeed.

Thanks. I am still 'dialing it in'. It's easy to get it working well, but not so easy to get it working perfectly, IME so far.

 

[FreezerBoy]

sry, didn't mean to post in the middle of your discussion.....

next time, you might want make the first 4-5 posts in a row, then go back and edit them with what you want to say. so all your info is together.....

No sweat. Readers that want to read spurr's posts alone need only click on his name and use the filter option. Makes everyone else's posts disappear.

 

[spurr]

Oh yea,

All told, the setup above* would cost about ~$1,500 give-or-take, at current online prices. That may sound like a lot for a single 1,000 watt HID, and I would be inclined to agree (in most cases); however, if someone has some money to spend and wants a great system, it's easily worth the setup cost to use with a single HID.

If a used water chiller can be found/purchased, the price would drop, a lot. The majority of the ~$1,500 for my setup came from the ~$1,000 for the water chiller. Likewise, if the water pumps can be bought used, more money could be saved. I know where I live there is a small but thriving aquarist community, where used a chiller as well as pumps might be available. I bet if at least the water chiller was used, the cost for the whole setup would be about (or less than) $800.

If buying used just make sure to get the chiller BTU and pump GPH and max head lift.

I like the setup I have because it's not limited to one HID, as shown by the pics above. I think I could hook up at least two 1,000 watt HID lamps like the setup above, and still be fine. Right now I have a 400w MH running in the SS II, but this week I am buying a 600w magnetic ballast and will run my backup Hortilux SuperHPS; so the chiller will have to cool 1,600 watts of HID, instead of 1,400.

* water chiller, two water pumps, two Iceboxes, Icebox thermostat, hoses, clamps and connectors.

 

[zor]

cool setup and indeed, there is not alot of info on these setup.

The chiller is indeed expensive. However, it is stealthy the way you have it setup. Could be a decent way to setup a nice tent grow in a condo without drawing any attention.

 

[spurr]

@ all:

I just edited the first two posts a bit, for accuracy and correctness, but also to make it easier to understand and put into action. I hope it makes using the info I posted easier ... I tend to ramble on ...


@ zor,

Thanks. Yes, I agree on the stealth issue, that is exactly what I did in my apartment. I had a neighbor ask why I need a water chiller, I told her it's for my fish tanks, nice and easy

 

[spurr]

FWIW, for smell removal in my closed-room setup focused on stealth to my neighbors, in my grow room I have:

Two Organic Air, model "6 inch Deau Passe" filters (they use "triple layer charcoal fiber filter elements"; and I'm not sure they do a good job): http://www.organicairfilter.com/product_detail_triplelayer.shtml

One Can-Filter, model "75" filter: http://www.canfilters.com/canfilters_75.html​

And I do not let RH get above ~60%, ideally my canopy/room RH is 55%, because once RH hits ~65% active charcoal in the Can-Filter (and all carbon filters) are much less able to remove smell efficiently/effectively, to the point of not removing smell noticeably.

 

[Oldmac]

Hey spurr,

First, nice setup and explaination of the chiller system. IMHO a well designed chiller system is more efficent then an AC setup.

If you don't mind I'd like to tell you what I have done. Just recently I needed to up size the light in my mom/veg room from 400w MH to 600w MH. Temps had been borderline with the smaller light and I knew would be too high with the larger 600w. I did the ice box routine on an air-cooled hood plus added a reflector insulation cover. I also added an ice box to my flower room light, that didn't need much cooling plus a stand alone icebox in my work area.

For cooling resivior I used a 30gal plastic "pickle" drum, but instead of using a compressor based chiller, I used a 3/4" soft copper coil in the drum that takes incoming water to the house and runs it thru the coil first. The water temp from my well tank is 52'F year round and everytime water is used in the house that 52'F water runs thru the copper coil. Kinda a poor man's geothermal unit. The only electric used is the 3 fans at each ice box. It has proved to be very effiecent and has made for very controlable temps in all three rooms.

Hope I added something here.
OM

 

[spurr]

hey OldMac,

Nice setup, I wish I didn't have to use the water chiller, too!

 

[spurr]

@ all,

I figured I should post up some pics of how I have my grow setup, to increase irradiance ...

I place SunSystem "Sun Sheets" (link to product) reflector inserts (the same 95% reflective pebbled insert found in SunSystem reflectors) along the outside of my canopy, to increase irradiance for the plants with lowest irradiance.

I am getting an extra 50-150+ umol/area^2/second for some plants on the outside edge of canopy, using the reflective sheets. So now my peak irradiance is ~900-950 umol/area^2/second and lowest irradiance is ~550-600 umol/area^2/second. Still not ideal, but better than what it was, and better than 99% of other growers using a stationary light and square canopy (my canopy is rectangular). All that is possible because of the simple fact I can see the exact irradiance anywhere along the canopy (I love using my quantum sensor; it's a must for every indoor grower IMO) and adjust the grow setup accordingly.

Once I get the 600w ballast and start using the 600w Hortilux Super HPS, instead of generic 400w MH, the irradiance will be even better. My goal is for each plant to get at most ~900-950 umol/area^2/second, and at least 700 umol/area^2/second; but ideally all plants would get 800-950 umol/area^2/second. The lowest irradiance I begrudgingly accept, if I cannot 'fix' it at this time, is 500 umol/area^2/second.

I find once irradiance exceeds ~1,000 PPFD (e.g., ~1,000 umol/area^2/second) for the whole daylength, I find plants are hindered, ex., chlorophyll seems reduced, as well as growth, etc. This topic is about Daily Light Integral ...


Anyway, here are the pics of my setup, with the Sun System 'Sun Sheets' in place:

• Sorry for the poor quality pics, I used my phone camera.

 

[cracka magik]

Don't take this as trolling, just my reasoning and research in defense of a simple AC

Don't take this as trolling, just my reasoning and research in defense of a simple AC

I've looked into this briefly before and realized that it really can't be as efficient as it is being advertised and the equipment is far to expensive, but with your very well put together and informative post I decided to look into it again, and unfortunately came to the same conclusion.

I was interested in if my 1/2 hp Active Aqua chiller was in any position to do some extra cooling to take some load off of my ac since its way over kill for my 100 gal hydro system and its only 360 watts to run, awesome right? This all sounded great until I found out it’s only rated for about 4000 btu or so and was therefore unable to cool shit. Well except for the hydro system it was built for…

So at this point I was disheartened, but still invested in this idea enough that I at least wanted to find out what I really needed to water cool my 4k garden, and with very little work I found hydro innovations fancy dancy calculator:

Cooling System Sizing Chart

Oh, only a 2 hp, 24,000 btu model for my 4,000 watt setup? This is of course where I hit a dead end and am now kicking myself having spent about an hour and half researching different products and methods of water cooling such as the expensive air handler I now needed to buy to replace my heat producing dehuey... or use alongside as the fine print said…

The 2 hp model is selling online for about $2,500. Now I can't find a price on the air handler but I'd guess it’s more than another $1,000. Then I’d be looking at a lot more expenses and unnecessary work hanging iceboxes and hooking up plumbing.

The price alone really puts me off, but where I'm left feeling perplexed cheated is when I look at the power consumption of these units. I can't find the watt usage of the 2hp chillking, but if the law watts = amps x volts is somewhat correct for this kind of appliance then it’s at 11 amps x 220v = 2420 watts. This puts it right on par with a 24,500 btu window ac which are around 25,000 watts, same amps, same volt, but only $500 and can handle everything in the room and don't require ice boxes or heat shields for hoods and a separate air handler since that's what an ac does...

In defense of the water chiller, it probably won't be on all the time, but with my little experience with ACs, neither will they especially a 24,500 btu model for a 4k room. However, if the water chiller is on less than the AC would be it’s still going to take years to pay off the extra expense from minuscule electric savings and you’re never going to pay off the hassle of having all that extra shit in your grow room and outside your house.

So my conclusion sits at this absolutely makes no sense for my own requirements, but it could work for a lot of money for a small setup if you are attempting to keep your cooling stealth as spurr has provided which obviously is working great for his own situation, but I urge you to look into this before jumping in and joining the rest of the miserable others who first bought the 1/4 hp to chill a 1k when there are other far cheaper and more effective/efficient methods out there that I’m sure they learned of afterwards. I still just think that air cooling is the way until there is greater innovation in water cooling (like water chillers that are more efficient than cheap window ac units) or you can ditch the chiller.

Hey spurr,

First, nice setup and explaination of the chiller system. IMHO a well designed chiller system is more efficent then an AC setup.

If you don't mind I'd like to tell you what I have done. Just recently I needed to up size the light in my mom/veg room from 400w MH to 600w MH. Temps had been borderline with the smaller light and I knew would be too high with the larger 600w. I did the ice box routine on an air-cooled hood plus added a reflector insulation cover. I also added an ice box to my flower room light, that didn't need much cooling plus a stand alone icebox in my work area.

For cooling resivior I used a 30gal plastic "pickle" drum, but instead of using a compressor based chiller, I used a 3/4" soft copper coil in the drum that takes incoming water to the house and runs it thru the coil first. The water temp from my well tank is 52'F year round and everytime water is used in the house that 52'F water runs thru the copper coil. Kinda a poor man's geothermal unit. The only electric used is the 3 fans at each ice box. It has proved to be very effiecent and has made for very controlable temps in all three rooms.

Hope I added something here.
OM

Oldmac, that setup is an awesome idea, you could definitely set that up with an automated thermostat to control the flow of water when its not in use but unfortunately you would be wasting water... most don’t seem to mind using some though if you look at all the waste from RO, might as well use that for something like cooling! I believe that this is the same concept of a standard heat-exchanger.

Oh and btw, stealth isn't a benefit for my recommended chiller for it’s an outdoor unit, I think they do have a stealth one though for an extra 2-3k. You could also just pick up a similarly rated ac unit off craigslist for cheap remove the cover and bend the coil into the water tank for a whole lot less and achieve the same result with possibly even more efficiency with a high eer rated AC.