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monkey

Thermostats

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Greetings all,

I was wondering if anyone has bothered with any sort of thermostat systems in their fruiting chambers? I once knocked up a temperature and humidity controller using an Arduino (programmable controller) for an unrelated use, which I think I might use when I try to grow some Shiitakes, given the FREEZING winter we are having.

does anyone bother with such complicated solutions or do most species not really care enough to justify it?

I could explain how I did it for anyone interested. The most expensive bit is finding a humidity sensor that works at high humidities. Temperature-only is a piece of cake.

Monkey

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Hi monkey, I'm also interested if others think it's worth it. I've been planning to do a similar thing as I work away a week at a time.

As you say the humidity sensor is the tough part. it seems to be a difficult measurement above 95% rh. Did you find An appropriate sensor?

I've bought a wine chiller clearance from target, it is pelletier cooled. I've also bought a cheap heat/cool controller from ebay. This will take care of temp, but unsure about humidity.

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Write up a tek mate,imsure all the shroomies here would be dead keen to see it!

And yeah, most of us have all kindsa bizzare contraptions and devices controlling all manner of difrent fruiting variables. My Fc looks like the board game mousetrap LOL, pipes n censors and timers everywhere LOL

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You'll find that an Airconditioner thermostat will fit the bill as it's range is what you seek.

I'd go for one from a "Window-Rattler" that's dead (compressor failure) and has a functional thermostat.Turn it back an forth with your hand on the sensing bulb and wait for a "click" sound each way,that's the on/off.

Mount this fellar in a Jaycar style box and it would do the trick.

I am an experienced fridgey/electrician ;-)

Of course power off before removing ANYTHING.

If you can source one,pm me and I'll draw up a wiring diagram.

Cheers

mesc...

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As you say the humidity sensor is the tough part. it seems to be a difficult measurement above 95% rh. Did you find An appropriate sensor?

There are different types of sensors, resistive, capacitive etc. capacitive seem to be the best at high humidities while still only paying a few bucks. I'm using a Humirel HS1100 datasheet here which claims to have an accuracy of 2% below 90% humidity. I've never had to use it above 90%, so I don't know how it goes up there.

Question to those in the know, how would you describe the relative importance of all these variables? Does temp alone and rough humidity control (spraying every now and then) pretty much cover it? Considering a *wide* variety of species too.

Since I've already got the Arduino I'll set it up to control:

-Temp

-Humidity

-Fresh air exchange (using a CPU fan)

-Carbon dioxide levels (overkill but meh. can cost round $50)

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Monkey what kind of relay/circuit are you using to switch the higher load devices from the Arduino?

And how are you planning to control temperature?

I am planning to use an aquarium heater in a container of water as my incubator heater.

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Hey occidentalis, an aquarium heater in water works pretty well. But a flexwatt heater mat i have found to work better and not need a container of water. Also because its flat it doesnt take up much space.

If your in Sydney there is a place called extreme pets that has this heat mat on a roll, i think about $35 a meter. Just cut to size then crimp on the connectors and wire it up. Of course if you aint much good with wiring and stuff get a buddie who is good at it to do it. I also have a plant heater cable that i have epoxied into an aluminium plate for an incubator heat source,the plate really holds the heat and keeps an even temp.

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oh yeah if you can add any thermal mass to the heat pad, such as an aluminium or steel plate it will help heaps, even a baking tray aint to bad

Edited by El presidente Hillbillios

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oh yeah if you can add any thermal mass to the heat pad, such as an aluminium or steel plate it will help heaps, even a baking tray aint to bad

Does that mean the thermal mass of the water with the aquarium heater would be good? I guess the water heater will also add humidity to the room.

Does anybody know anything about this kind of heating and whether it's of any value?

http://www.ebay.com.au/itm/GREEN-HOUSE-PORTABLE-HEATER-GREENHOUSE-TUBE-HEATING-x2-/300564333194?pt=LH_DefaultDomain_15&hash=item45fb07c28a

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When mycelium colonises grain or a substrate it is in effect an exothermic process.

Adding extra heat can speed up the colonisation of grain spawn or PF cakes but after that stage adding extra heat is only really needed if temperatures drop too far below the minimum range that your chosen strain will fruit at.

Cubensis strains can tolerate a very wide temp range and if fruited from a bulk substrate in a monotub they can fruit well at ambient temps lower than 15 deg because the mycelium generates its own heat.

Incubating after spawning to a bulk substrate will many times cause the project to contaminate.

This is due to several things, overheating of the substrate and condensation forming on the walls and running down the sides making the substrate wet.

Overheating can happen easily as the mycelium adds it own heat which rises and falls in cycles, added to the incubators heat that can push the substrate temp too high.

Condensation forms as a result of the hysteresis of thermostats and the corresponding lag in re-heating the heating element, causing a hot then cold environment.

If you are going to add heat, try to keep the temps on the low side and try to reduce any hysteresis from the heating circuit.(adding thermal mass helps a lot in that respect and water is the best way to store thermal mass at the temps needed for shrooms)

Humidity is best controlled with the design of your fruit chamber, electronic control needs to be way too complicated to achieve the same results you'd get from a plastic box stuffed with polyfill ie a monotub, controlling temp and humidity at the same time needs a closed loop system that tends to fight itself at high humidity levels needed for mushrooms.

Most people fail with monotubs when they only get a few fruits forming around the edges, all that is is poor air circulation - run a fan on oscillate in the room and monotubs look after themselves- no need to complicate it with high tech gadgets.

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if anybody is looking,

i have the following for sale, as i desperately need to fund my education addiction (no seriously, i'm even tempted to start selling all the glassware that i stole from organic chem j/k... no really, i'm kidding, i sold all that glassware years ago) :P

email me if interested:

1 x 300w titanium coated submersible heater. german made precision baby, none of that mass produced third world shizzle.

1 x thermostat, with stainless steel probe, temperature range is 20-40C, graduation is 0.1C. not sure if those temp ranges are of any relevance in the land of mycology, but i have a feeling that they can be reprogrammed.

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Thanks for the replies everyone,

I guess I'll finish my Arduino system since its half made anyway, even though the consensus seems to be that you can get decent results with a much simpler setup.

Thermal mass is a good thing to get right if you go down the thermostat path, too little and you get annoying temperature jumps, too much (big bucket of water or something) and it might take too long to heat up the air every time you exchange it with the outside air.

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The problem i have found with water containers of water used for heat, is they evaporate of really quick and soon leave your heater in the open air. Plus an aquarium heater take a while for the element to heat and cool, this is no problem with a 100 litre fish tank. In a smalll container it can lead to early failures and very uneven temps.

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Wouldn't water evaporating off be a good thing in this application?? Driving humidity higher?

Also, couldn't you stick a probe heater to the floor of the tank? Who says it needs to be mounted vertically? Then the water level would have to get VERY low before exposing the element.

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I was planning to place the aquarium heater horizontally in a large rectangular tupperware type container with a lid, holding probably about 6L of water. I was going to drill a hold in the lid for the heater cable, and then silicon the hole sealed around the cable.

I figured that this amount of water would be enough to hold some thermal mass and prevent sudden fluctuations due to opening the door, but not be so much that it would take too long to heat with a heater designed for larger amounts of water.

the purpose of the incubator I am building is for small grain bags, liquid cultures and petri dishes, so I don't want a highly humid environment (too much moisture increases contamination). Hence the lid on the container.

My only major concern is that many aquarium heaters (not sure about all) have an automatic shut off above a certain temperature (which is often quite low). This would mean that the water may not be able to get hot enough to warm the entire space within the fridge.

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Within the fridge...hmmm what about setting up a longer vessel? Like those pieces of PVC pipe with a screw cap on each end that 4WDs have on the roof racks. This could spread the heat around. No wait, pvc might insulate. Copper at a reasonable diameter would be far too expensive. Maybe an old piece of cyclone fence post?

Heater at the bottom, warm water rises, cold water falls...that kind of thing.

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you mean put something like that vertically in the back of the fridge?

I guess that could work.

Only downside would be then you'd have to cut holes in all your fridge shelves to fit it through them!

Does it matter if the material insulates? Some heat will still leak out, and as long as the heater can get the water hot enough to warm the fridge space up to the right temp with that bit of heat, you're fine. The water inside the pipe will stay hot for longer, and it might reduce the rate at which your heater has to come on and off.

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Ideally you'd want your heating tube to have maximum surface area, so either lots of tubes, a spiral with a return pipe or even a pipe with 'fins' along it's length, to dicipate the heat away from the tube and into the fridge. The central column of water will control the fluctuations, and it'll all behave once the space in the fridge comes to temp, due to insulation of the fridge.

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El cheapo plastic tubs,one or two smaller and inside the other,verm casings,water,peroxide,bubbler,fish tank heater,top lid tilted......can't go wrong!

:wink:

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A thermostat isn't a neccesity in many cases. Where one may have need of one, say like in winter where there may be large day-night temperature fluctuations, I've found that the probe thermostat sold for reptiles works very well.

Ebay Reptile Probe Thermostat

Edited by Mycot

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I'm soon to embrace the world of mycology with Agaricus & Pleurotus on the cards. In the planning stages with equipment, and have already been considering how to semi-automate the controls of a fruiting chamber (my other hobby demands precise controls through stages of the process also).

I have several STC-1000 temperature controllers rigged up for various purposes, and these babies basically act as an inline switch that's triggered by a set point. It can be wired for heating or cooling. This had me wondering if there was a similar device for switching a humidity device on/off at a set point, and sure enough there's one that looks like it's by the same manufacturer. - Link - I don't know a lot yet regarding humidity variables, or even what to use for generating a humid environment, so cannot speak first hand of the controllers, but if it performs anything like the ST-1000, then I'll be impressed.

These devices require the user to wire them up. As a 240v device, if you dont understand electrical principals, please consult someone who does. These could be very dangerous to you or your family if you don't rig them up properly.

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Excellent, i'll be buying one of those. I have one very similar for temp control for my brewing, but that one has temp and humidity (and it's a fair bit cheaper than i paid for the other one)

Thanks

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yeah that looks somewhat easier to use than those programable chips. I wasn't looking foward to having to learn all that programing stuff mushroom growing is fiddly enough

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