Regulating Grow RoomTemperatures

Psilocybe cubensis mushrooms and mycelium are generally the happiest between 22°C – 27°C or 70°F – 80°F. While they will grow in colder temperatures, their growth rates will be be far from nominal, and not ideal for cultivation. This post covers various ways you can heat up or cool down your growing environment so that you can hit those ideal growing temperatures. Using a good quality control thermostat which is able to hold up to the high power requirements of the heater or cooler is key.

Temperatures for growing mushrooms
Temperatures For Growing Mushrooms

Table of Contents - Regulating Grow Room Temperatures

Getting Ideal Temperatures In your Grow Room

Psilocybe cubensis mushrooms and mycelium are generally the happiest between 22°C – 27°C or 70°F – 80°F. While they will grow in colder temperatures, their growth rates will be far from nominal, and not ideal for cultivation. At temperatures over 28 °C or 82 °F, growth may get stunted and the mycelium is more susceptible to contamination. If you are trying to cultivate in temperatures outside this range, you have several options to help regulate the room temperature and bring it to a level which is conducive for growth.

If Grow Environment is too Hot

So, what can you do if the grow environment is too hot? If you have an AC in your home or grow room, then keeping the optimum temperature is just a matter of setting your AC temperature control to about 76°F or 24°C.  If you don’t already have an AC, you have two options: You can purchase a portable air conditioner, although these are pricey ($250-$500). These usually require a vent hole from your grow room to the outside, which is typically done through a window. The other and less expensive option is a small portable misting air cooler. This cooler chills the area directly in front of it and can be used in any size space. If you intend to use the InkBird Thermostat Regulator we recommend, make sure your Portable AC doesn’t draw more than 10 Amps or 1500W.
Amazon Link
Portable ac cooling unit

AC Unit Strength (BTUs) and Grow Room Size Considerations

A British Thermal Unit, or BTU, is an international energy measurement. By definition, a British Thermal Unit is the amount of heat needed to raise one pound of water, 1° Fahrenheit. The table below gives a rough estimate of the AC Unit Strength (BTU) which you will need for cooling your space, according to its size. For a more precise calculation, you can visit this link.

BTUs per Hour Room Size (m²) Room Size (ft²)
5000 9-14 100-150
6000 14-23 150-250
7000 23-28 250-300

If Grow Environment is too Cold

In cold climates where indoor temperatures fall below 20°C or 70°F, you will need a heater to raise the grow room temperature. You should choose a heater that is appropriate for the size of your room. To this end, you can refer to the table below. You should also pay attention to safety considerations when choosing a heater. We like the heater on the right (see picture and link) because it will automatically shut off if the heater falls over, thus preventing fires. If you intend to use the InkBird Thermostat Regulator we recommend, make sure your heater doesn’t draw more than 10 Amps or 1500W.
Amazon Link
Electric heater for mushroom cultivation

Heater Strength (Wattage) and Thermostat Considerations

Heater Watts Room Size (m²) Room Size (ft²)
250 4 43
500 7 75
750 12 129
1000 14 150
1500 21 226

InkBird Thermostat Power Draw Considerations

An InkBird heat thermostat can be used to accurately regulate grow room temperatures. This is required as both the ACs and heaters are not sensitive enough to accurately control the temperature by themselves. The InkBird thermostat shown to the right is a reliable device which works well, and supports electric devices that draw up to 1500W.

 

Amazon Link
Temperature and humidity sensor

4 Responses

    1. I haven’t had much experience with heating blankets, but the little I have showed that you really need to dial in the temperature correctly, otherwise it’s easy to overheat the tub. If the heating blanket has a timer or a temperature gauge, you can try to fine tune it that way, otherwise, you can try regulating the temperature by using an electrical timer to run the blanket intermittently. Can you provide more information on how you use your blanket? Thanks for the input!

      Reply

  2. There are as many good ways to grow shrooms as there are aspiring mycologists. I used a heating blanket successfully for my last grain spawn. The temp had to be monitored twice daily with adjustments necessary to keep at or near 25°C.
    For tighter control over FAE, temps and light needs, I used a Martha tent, mini exhaust fan and humidifier alternating on/off with timers. I got the 4-tier model tent, $50. For temp control, I use an adjustable aquarium heater in a plastic shoe box of water beside the humidifier on bottom shelf. You still have to make tiny adjustments almost daily but the compact setup suits me and my space. Also Amazon has cheap digital thermometer / humidity % display with probe to monitor each tub substrate.

    Reply

    1. Sounds very interesting! I assume you live in colder conditions? Would you be able to describe your set up in more detail and provide links to the hardware used?

      Reply

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