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Can someone tell me the most efficient way to heat my fish tank water?  Thanks  Doc

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Here's a family pic next to the composter. That little guy Ariel Fisk standing behind my blonde daughter Erin is now working for that wood gas gen co GEK in CA. Here is their plans link:

http://wiki.gekgasifier.com/w/page/9872593/Inventory-of-Online-Wood...

BTW compost is another good way to ad heat to the gh. 160 deg F easily attained.

Jim Fisk said:

Jon count me in as well.

Been collecting info on woodgas/gen for years and my nephew works for a co in Cal that makes parts and complete units on a pallet but again expensive. I would be happy to pay for your time or trade for my 50 page plans for making my high rate composter that I also sell at my Ebay store under Fiskfarm. (That was even written up in Yankee Mag.) I have a 4kw gen that would be about right. I would be tempted to dig yet another hole in the ground for a muffler so we don't have to listen to the bloody thing:-)

Hi Jon, I have a lot of questions becasue I need to understand the concept on what is being done so with those figures would I get approximately 55,000 Btu's per hour or would there still be more from the gasifier?

I have no idea what 4kwh would give me in electricity but hopefully run my 2 air generators and 2 pumps at night.

What basic equipment would be needed? Am I looking at a generator, building a gasifier and other items to go into the generator, some kind of large hopper and some kind of heat exchanger to get to warm the fish tank nutrients directly or another water storage tank?

Is the idea then with this setup to be able to heat the fish water or another water tank and then get some power to run things and also be able to heat the greenhouse?

In heating the greenhouse would I need another heat exchanger to get warm air into the greenhouse or would the gasifier have the ability to put its output into the greenhouse? Or is the gasifier in the greenhouse and the heat is available then?

I would also need a large enough place to store wood chips and find a source for wood chips. I am out in the country so getting that sent to me might be a problem. Can we burn other things in the gasifier if I can't get wood chips?

Sorry for all the questions but it will help others as well to see what is all involved. I have a 1500 sqft greenhouse and need a lot of Btu's per hour to heat it. Everyone has said that if my waters are 70 then I need my air to be as close to my air as possible so I do not get condensation. heating a 1500 sqft greenhouse to 70 would probably take 200,000 Btu's per hour unless I was able to make temporary smaller inside hoops and spaces just above the lettuce rafts and nursery trays thus cutting the space needed to heat to a way smaller area and then use the 55,000 available from what might come from this setup if I understand all of this correctly.

Jon Parr said:

Oh boy, Joe, I've never worked out that math. And I haven't run it for any length of time to give you much personal data on wood consumption, heat recovery, kwh, and all that, but I can throw some numbers I remember as guide lines. Pretty generic, and in case my memory fails and any of you can correct these numbers, please chime in.

- fixed rpm gasoline engines are about 20% efficient, maybe a bit more for a new, top of the line, fuel-injected, super-ninja Japanese model, and I'm sure there is a bit of loss in the generator portion of genset, so let's just call it 20%. That means if you have a 4 kwh gen running full load, then you are using 20 kwh of fuel to keep it running, giving you 16 kwh of heat byproduct (assuming all waste is heat, which it not, but close enough to call it a wash). 16 kwh is about 55,000 btu, and that is just in the generator, not counting the heat emitted by gasification (which I believe a downdraft gasifier is about 80% efficient, leaving 20% of the original wood energy also available as heat)

-a lb of dry wood is about 1 kwh, so if my above estimate is correct, then my 4 kw generator should burn about 20 lbs of wood per hour. 

-coincidentally, I remember reading somewhere that 20 lbs of wood is about equivalent to a gallon of gasoline, so the gen should burn about a gallon per hour if running on gas. I don't have any idea if that's right, but it's probably in the right range. (actually I just looked that figure up, and gasoline is more like 33 kwh per gallon, however syngas will burn more efficiently in an ICE than gasoline, so maybe the 20 lb wood/gallon is still accurate for argument's sake)

- a cubic yard of dry wood chips weighs about 640 lbs, so running my generator for 10 hrs per day should use about 200 pounds, or a third of a yard. 30 days in a month comes to 10 yards per month, which is 1 heaping load from my local tree service friend. Considering my tree guy averages 3-5 loads per day, I think I can count on free energy for a good amount of expansion.

Anyway, unless I missed something (cross my fingers), a 4 kwh genset running on a wood gasifier should consume about 20 lbs per hour and supply 55,000 btu's of heat in addition to 4kwh of electricity for 10 hrs per day, using 1 full dump truck load per month. 55,000 btu's at 10 hours per day, equals 550,000 per day, enough to raise 55,000 lbs of water (6900 gallons) 10 degrees F, or 5,500 lbs of water (690 gallons) 100 degrees F, which we call in these parts "fish stew".

Jim, what kind of exhaust stack would one need for a gasifier (since building a brick chimney in the GH is out of the question, yet the fancy double walled chrome stacks used in leui of brick with 'regular' wood burning boiler/stoves cost more here than the 'regular' wood burning boiler/stoves themselves). I'm guessing nothing fancy is necessary? 

Hi Bradley,

 

I think you and I have similar size setups, and I like the sound of your plan. Do you have any concern about the insulation getting wet from splashing or rain? My AP system is in a greenhouse, but the plastic does not yet extend all the way to the ground - in the summer the open sides provide for better air flow, but it also allows rain to come in the sides. My first priority is likely to better enclose the greenhouse - then something like the insulation/plastic wrap you plan might work for me too.

Also, I plan to make a heater like you have, but am wondering why you chose to put inline with the pump water rather than submerging into the tank to make sure it never was exposed to air? Obviously submerging means the back (electrical side) needs to be in a watertight PBC pipe leading up to the top of the tank...
 
Bradly said:

Ok, I've given a lot of thought to this, and I know what I'm going to do to my system.

I'm going to wrap my fish tank with unfaced pink insulation (3") from the top...all the way down to and tight to the ground. I'll probably paint the insulation black with some spray paint.  Then I'm going to wrap 2 times around the tank with some packaging roll wrap (20" wide roll material) {the same stuff they wrap around full pallets of boxes to hold them together} to hold the insulation in place as well as providing a tight vapor barrier.  This will be probably $20 for the insulation and $10 for the roll of plastic wrap.... so $30 total.  I think it will work and cost is low. I might even get a side benefit during the day of having the sun shine thru the plastic wrap and kind of heat up the insulation and the dead air space the insulation is in.

I'll do some kind of custom cover insulated too ...haven't worked out the design idea on that yet on the lid...will need to let in air.

I am also thinking I'll pull a layer of this same plastic over top of the grow beds (if I decide to keep water flowing to the GBs), and that will make the growbeds act like little greenhouses during the day accumulating some heat in my river rock grow media.  Then I'll rely on the heater for late evenings and nightimes.

I think this will work.

   Lots of good thoughts. I considered a rocket heater,and running the exhaust from one side of the GH out the other.

Insulated well with cob it would radiate some heat.From articles ive read the exhaust should about come out clean.

     I would put it outside in a steel insulated shed.   Ive used small HP systems and now im doing a lot of reading on making a larger commercial setup.Much of what i read sounds like some large electric bills! Ive also worked with solar and low draw pumps and figuring out how to make this all work is what im looking at.

Yikes, I haven't rec any notices from this thread. Lots of others. I came by to see if it was dead!!

So, I plan on placing some wall supports and then attaching a bed rail welded support for metalbestos pipe of which I have collected lots at yard sales. I plan on prob 3 sections as I want it well above plastic roof. Single Wall thru a thimble and 90 into MB. Spark arrestor at cap as it will be up wind of GH.
Stove is half finished. Will post pics below. Havn't built one in over 40 yrs. Been adding a few tweaks as I go. These are old. Already made changes at elbow.

Vlad Jovanovic said:

Jim, what kind of exhaust stack would one need for a gasifier (since building a brick chimney in the GH is out of the question, yet the fancy double walled chrome stacks used in leui of brick with 'regular' wood burning boiler/stoves cost more here than the 'regular' wood burning boiler/stoves themselves). I'm guessing nothing fancy is necessary? 

Sorry to drop the ball here. Ariel Fisk works at Berkeley. They used one for elect at his wedding in Austin! Very cool (and green) Let me know when u get the chance to do write up and pics. Building my wood stove right now as it's getting friggin cold around here and Sandy has already dumped 8" of snow on us.   I can send u the composter plans on cd any time.

Jon Parr said:

Does your nephew work for the GEK folks in Berkeley, or another? You don't have to pay me for anything I've done and can share, but I'd love a copy of your composter. Amen on the muffler noise. I plan to box the genset in designated sound room (well, more of a little cubicle than a room), and the exhaust gets piped into the concrete slab under the FT's, which should deaden the noise, I hope

Jim Fisk said:

Jon count me in as well.

Been collecting info on woodgas/gen for years and my nephew works for a co in Cal that makes parts and complete units on a pallet but again expensive. I would be happy to pay for your time or trade for my 50 page plans for making my high rate composter that I also sell at my Ebay store under Fiskfarm. (That was even written up in Yankee Mag.) I have a 4kw gen that would be about right. I would be tempted to dig yet another hole in the ground for a muffler so we don't have to listen to the bloody thing:-)

Here are some pics of the last minute changes I made to the sec air intake tube. I did this to avoid tha ashes down the tube prob.The 4" exhaust burner pipe will reach down to that small pipe which aims hot air at the hot coals. That's a bearing flange cover ot the end. Now to find a 4" x 15" pipe and pu another barrel.

Finished wood gasifier wood burner HW/HA for GH. Here are some photos for those interested in using wood. Right now I am running one 3/4" x 6ft SS loop as can be seen in photos (it blackens by itself). I will make a coil for the other side soon and I will put together a YouTube slide show of construction. Brings up temp about 10 F in 24 hrs for 1500 gal while it heats the room. For those who have purchased the plans I will be sending you about 60 pics of the build. The blower is a new addition and works amazing. Quickest start ups ever. The water has been hard plumbed since these were taken. The chimney is Metal Bestos 6" supported by my bed iron mounts. I will post some pics of that soon. I collect sections at yard sales and such at a fraction of retail.

I'd like to thank Jim for providing the basic design for his gassifier. I built (a slightly modified) one. This thing bellows heat like Fafnir on crystal meth. I could not find a decent squirrel cage fan here, so I'm making due with an 1800Watt AC hair drier that I've converted to to a 15-18Watt DC blower (9 volts at the moment). At first I had the silly notion that I could just remove the heating element from the circuit and continue to use the motor and switch as an AC device. This hope quickly dissipated when I opened the thing up and realized that the heating element is basically wired as a big resitor. My first thought was to replace the element with a suitable resistor, which seemed silly after about 20 seconds since any resistor would consume as much energy and dissipate it as heat much like the original heating element would. So I stripped the whole shabang down to what it was at it's very core...A permanent magnet DC motor capable of running on 6 to 20 (or perhaps 24) volts. This proved to be a much better idea. Cheaper too.

I'm working on getting it to run on a switchable 12, 15, 16, 18, 19, 20, or 24v circuit, I don't think it will draw much more than around 300mA, but am afraid to mess with it anymore right now because it's all I have and if I fry that little motor I'm screwed. For now I will leave well enough alone. The volume of air the little motor moves is decent enough, but it is a very low pressure design (which kinda suck for this app). I'm sure that if I had a proper mid-pressure blower, this stove would be even better.

There is a big 50cm, 240v 1.2Amp fan moving the hot air throughout the GH and helping to keep the back of the stove cooler. This was ridiculously strong, so I wired in a potentiometer and now have a smooth choice of operating speeds (and electrical energy consumption). Standing in front of that thing, before I wired in the pot was like standing in a wind tunnel...and I was worried that the motor wouldn't be strong enough...I guess I over do shit sometimes...Anyways...

The week before last, during a cold spell, when it was -7 to -8C outside I was able to obtain a delta-T of about 10-12C degrees in a 2130+ square foot GH. The glass panels are 4mm thick and i believe the r-value of the glass is 0.91 (though I am not 100% on the exactness of that number...at any rate it's in the ballpark).

This surpassed my expectations and allows me to drastically reduce the amount of propane I now need to use. Last Feb. we had over a month of sustained -13 to -25C temps, this year, with Jim's help I'll be ready. So thanks once again Jim.

The only significant, non-cosmetic deviations from your design are; super beefed up metal drums (2.5mm wall thickness), a 5mm cold steel heat shield (L-shaped) above the burn tube yet below the baffle to protects the back of the drum. This heat shield doubles as a shelf on which fire bricks are placed...adding to the thermal mass of the stove. This necessitated an access panel on the upper barrel to get to the shelf/bricks. Those are really the only changes worth mentioning.

Vlad that is simply awesome. I never get tired of feedback especially when someone adds their own mods. I love it. We are running about 20F at night and the stove keeps the GH at about 45F all night no problem while heating the AP water as well.

Did you make a water coil for yours yet? Only problem I've had with that so far is if we get a power outage even for a minute, the coil looses it's prime and before long it melts the pvc connector. I plan on putting the pump and air pump on my 1400w ups (which is still sitting in the garden shed because I need to come up with 24v of batteries) so that can't happen again. I have also been designing in my head a low inertia ck valve for the loop because as you know flow is a delicate thing and requires easy working ck valves and I want it pvc rather than metal. I'll post some pics when that is done.

I only wish I had more DRY wood cut to the long lengths the stove loves. I hate to keep stealing the house wood. Here is my temp. solution



Vlad Jovanovic said:

I'd like to thank Jim for providing the basic design for his gassifier. I built (a slightly modified) one. This thing bellows heat like Fafnir on crystal meth. I could not find a decent squirrel cage fan here, so I'm making due with an 1800Watt AC hair drier that I've converted to to a 15-18Watt DC blower (9 volts at the moment). I'm working on getting it to run on a switchable 12, 15, 16, 18, 19, 20, or 24v circuit, I don't think it will draw much more than around 300mA, but am afraid to mess with it anymore right now because it's all I have and if I fry that little motor I'm screwed. For now I will leave well enough alone. The volume of air the little motor moves is decent enough, but it is a very low pressure design (which kinda suck for this app). I'm sure that if I had a proper mid-pressure blower, this stove would be even better.

There is a big 50cm, 240v 1.2Amp fan moving the hot air throughout the GH and helping to keep the back of the stove cooler. This was ridiculously strong, so I wired in a potentiometer and now have a smooth choice of operating speeds (and electrical energy consumption). Standing in front of that thing, before I wired in the pot was like standing in a wind tunnel...and I was worried that the motor wouldn't be strong enough...I guess I over do shit sometimes...Anyways...

The week before last, during a cold spell, when it was -7 to -8C outside I was able to obtain a delta-T of about 10-12C degrees in a 2130+ square foot GH. The glass panels are 4mm thick and i believe the r-value of the glass is 0.91 (though I am not 100% on the exactness of that number...at any rate it's in the ballpark).

This surpassed my expectations and allows me to drastically reduce the amount of propane I now need to use. Last Feb. we had over a month of sustained -13 to -25C temps, this year, with Jim's help I'll be ready. So thanks once again Jim.

The only significant, non-cosmetic deviations from your design are; super beefed up metal drums (2.5mm wall thickness), a 5mm cold steel heat shield (L-shaped) above the burn tube yet below the baffle to protects the back of the drum. This heat shield doubles as a shelf on which fire bricks are placed...adding to the thermal mass of the stove. This necessitated an access panel on the upper barrel to get to the shelf/bricks. Those are really the only changes worth mentioning.

BTW Vlad,

My blower came out of a residential dishwasher. The dryer blower. So ck out your local dump. The first place I shop! I still had to make a damper on it to slow down the draft. This morning's fire started distorting the rear of the drum it got so bloody hot.

My wife likes the stove so much she has me making another for the house and I plan to use a "Steelcat" 6" in that one for a super clean burn. The new drums seem to be a lot thicker as well. Will keep you informed.

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