Experimental Incubator/2.1 mamut tamna

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On this page you can find more info abot the experimental incubator 2.1 Mamut-Tamna prototype, where Tamna suggests locality where it was build and tested.

This prototype was build based on the blueprints of the 2.1 mamut within the Food Hacking Base group project which help was truly appreciated.


Desired features, goals of the prototype

This prototype was aiming to function in a same manner as 2.1 mamut measuring therefore the temperature within the incubator chamber, displaying it on the LCD display, allowing for heating and cooling functions set by button interface running software shared in our Github repository. The power was sourced from a standard computer PSU offering therefore 5 VDC and 12 VDC. For heating the peltier element was used, power estimated to 60 W. The distribution of the heat was carried out by two aluminium heat sinks and thermal paste which were cooled by standard PCU fans, each mounted on the top of the heat sink. The peltier and fans were controlled by Arduino through a circuit composing of darlington transistor multiplying the signal from the Arduino digital pin to switch on/off the mechanical relay providing the power for the fans and peltier (two separated outputs).

Below you can find two different set ups for testing. First, let's say temporary one had a polystyrene box as a chamber, size: a=76cm, b=46 cm and c=46 cm; V= 0.160 816 m3, front of the box covered by think polystyrene insulation and cardboard paper. The heating and cooling unit were attached on the top of the box (in the hole cut and sealed in the polystyrene). Second set up had "cooler box" as a chamber, size: a=55cm, b=30cm and c=29cm. The heating and cooling unit was set in a wooden frame made sealed by "polystyrene like" insulation and silicon positioned on the top of the box with doors opening at a side from bottom up.


Performance - Latest testing - cooler box



Heating Experiment 25/5/2014

Time (min) Internal temperature (t) (°C) External t (°C) Difference of internal t (°C) Sum of t difference (°C)
0 23.12 23.4 0 0
10 31.18 24 8.06 8.06
20 36.75 24.2 5.57 13.63
30 41.31 24.3 4.56 18.19
40 43.12 24.4 1.81 20
50 45.06 24.5 1.94 21.94
60 46.75 24.7 1.69 23.63
70 47.93 24.7 1.18 24.81
80 48.81 24.8 0.88 25.69
90 49.5 24.8 0.69 26.38
100 49.93 24.8 0.43 26.81
110 50.37 25.1 0.44 27.25
120 50.68 25 0.31 27.56
130 50.87 25 0.19 27.75


Temporary post about Marcel's experiment

Marcel is using a box made from 3cm layered plywood desks and insulated by 5cm PIR boards. The internal dimensions of incubator chamber are a=42.5, b=49 cm and c=45.5cm, total volume = 0.095m3. Two peltiers were used for heating and cooling type: TEC1-12709, which has peak power of 138W at 15.2V but rated 90W at 12V. At 12V the peak current is 7.5A at turn on which quickly settles down to 5.6A stable, which is only 67W, both for heating and for cooling per peltier, therefore 134W total heating respectively cooling power.


Performance - previous testing - polystyrene box

At approximately 20-21°C external temperature, heating the chamber for two hours resulted in 14.25°C increase of temperature from 18.56°C to 32.81°C (12.06°C temperature increase after first hour). Cooling at similar external temperature resulted in 3.62°C temperature decrease after 2 hours, cooling the chamber from 20.93°C to 17.25°C (3°C after temperature decrease after first hour).

I've shared a link to the Google spreadsheet so you can have a look on the values, however all of the values and graphs are shared below too.


Heating Experiment 14/4/2014

Time (min) Internal temperature (t) (°C) External t (°C) Difference of internal t (°C) Sum of t difference (°C)
0 18.56 20.10 0.00 0
10 23.10 20.00 4.54 4.54
20 25.87 20.10 2.77 7.31
30 27.56 20.30 1.69 9.00
40 28.75 20.40 1.19 10.19
50 29.81 20.60 1.06 11.25
60 30.62 20.70 0.81 12.06
70 31.25 20.80 0.63 12.69
80 31.75 20.90 0.50 13.19
90 32.12 21.00 0.37 13.56
100 32.37 21.00 0.25 13.81
110 32.68 21.10 0.31 14.12
120 32.81 21.10 0.13 14.25
130 33.00 21.10 0.19 14.44


Cooling Experiment 17/4/2014

Time (min) Internal temperature (t) (°C) External t (°C) Difference of internal t (°C) Sum of t difference (°C)
0 20.93 21.9 0 0
10 19.68 22.4 1.25 1.25
20 19.06 22.4 0.62 1.87
30 18.62 22.4 0.44 2.31
40 18.31 22.4 0.31 2.62
50 18.12 22.3 0.19 2.81
60 17.93 22.3 0.19 3
70 17.81 22.2 0.12 3.12
80 17.62 22.1 0.19 3.31
90 17.56 22.1 0.06 3.37
100 17.5 22.1 0.06 3.43
110 17.37 21.9 0.13 3.56
120 17.31 21.9 0.06 3.62
130 17.25 21.8 0.06 3.68