Experimental Incubator/2.1 mamut tamna

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

• Basic overview of the cool box set up
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  Overview of the set up of the experimental incubator 2.1 mamut tamna.

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  Close up on the heating/cooling unit, arduino brain and wiring.

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  Internal chamber with 500 ml swing top bottle to get idea about the real size.

• Heating and cooling performance 25-26/5/2014
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  Legend of Heating Experiment 25/5/2014: Legend will be filled up very soon ...

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  Legend of Cooling Experiment 26/5/2014: Legend will be filled up very soon ...

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

Here you can find data in an easy to work with data sheet form.

Cooling Experiment 26/5/2014

Time (min)	Internal temperature (t) (°C)	External t (°C)	Difference of internal t (°C)	Sum of t difference (°C)
0	26.18	26	0	0
10	25.31	26	0.87	0.87
20	24.81	25.9	0.5	1.37
30	24.56	26.1	0.25	1.62
40	24.31	26.1	0.25	1.87
50	24.06	26	0.25	2.12
60	23.87	26	0.19	2.31
70	23.75	25.9	0.12	2.43
80	23.68	26.1	0.07	2.5
90	23.62	26.1	0.06	2.56
100	23.56	26	0.06	2.62
110	23.42	25.8	0.14	2.76
120	23.31	25.7	0.11	2.87
130	23.25	25.9	0.06	2.93

Here you can find data in an easy to work with data sheet form.

Temporary post about Marcel's experiment

• Marcel's experimental incubator set up
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  Overview of Marcel's set up - brain, wiring and the heating/cooling unit at the top of the incubator (yes and fancy paper with notes so "he is actually doing science!" while I did not put a paper with notes on my incubator so I'm just screwing around ... :-) )

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  Whole box view.

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  Temperature reading is quite convenient, don't you think?

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.

• Heating and cooling performance - Marcel 22/5/2014
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  Legend of Heating Experiment 22/5/2014: Legend will be filled up very soon ...

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  Legend of Cooling Experiment 22/5/2014: Legend will be filled up very soon ...

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 and cooling performance
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  Legend of Heating Experiment 14/4/2014: Heating program was run to bring up the temperature in the incubator chamber to 42°C, starting at 18.56°C. Within the 120 min of duration of the test t=32.81°C was reached, therefore total increase of 14.25°C, with 10.19°C increase reached within first 40 minutes. The external temperature was changing minimally and it's therefore considered constant not interfering with the experiment. It can be concluded that the current set up with 60 W peltier and V= 0.160816 m3 of incubator chamber is not suitable for heating over 32°C. # Internal temperature difference is a change of temperature between within two time points = t change in 10 min.

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  Legend of Cooling Experiment 17/4/2014: Cooling program was run to bring the temperature in the incubator chamber down to 15°C, starting at 20.93°C. Within the 120 min of the test, the t=17.31°C was reached, 3.62°C total decrease in the temperature, 2.62°C decrease within first 40 min. The changes in the external temperature were minimal and it's therefore considered constant and not interfering with the experiment. In conclusion the current set up with 60 W peltier and V= 0.160816 m3 of incubator chamber is not suitable for cooling in general. # Internal temperature difference is a change of temperature between within two time points = t change in 10 min.

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