Real-time measurement Fullblack Indoor - 2nd Feb 2023

On the second of February this year, a cloudless day, Isabelle Persson, hotel manager at Quality Hotel Winn, conducted a test with Indoor in two adjacent identically sized rooms, about 25 square meters, facing southeast (almost east-southeast). This is because hotels can save a lot in heating costs by supporting rooms with a southeast-southwest orientation. During the test, two Fullblack Indoor were used in order to obtain measurement data.

The test started at 11.00, with a very narrow sun angle, and ended one hour later at 11.00 am. 12.00 as the sun disappeared around the corner. The rooms have thermostatically controlled heating and in room 101 (Indoor) the starting temperature was 21.3 degrees at head height and the same at knee height. The reference room 102 had 21.8 degrees and 21.3 degrees for the corresponding measuring points. The heating was turned off in both rooms when the test started. The ceiling/wall temperatures (measured at chest height) were identical, except for one tenth of a degree: rear wall 20 degrees, left wall 19.9 degrees, right wall 19.4 degrees and ceiling 19 degrees.

The ceiling/wall temperatures were measured 2/3 in from the window wall. The fan in Fullblack Indoor is 6 W, so the cost of running both for one hour is 12/1000 W x 2 kr, giving an operating cost of only 1.2 öre/Indoor(!) (2 kr is the price of one kWh/1000 W).

The reference room had no change in temperature after one hour, while the room with Indoor had already increased by 1.6 degrees (head height)/1.2 degrees (knee height) and the back wall by 1.7 degrees, the right wall by 1 degree, the left wall by 0.8 degrees and the ceiling by 1.7 degrees. In other words, very tangible temperature increase – for 2.4 pennies(!) in one hour. Even with moderate cloudiness, the room with Indoor had become warmer than the reference room. Quality Hotel Winn confirms with the test that a room is warmer with Indoor than without.


Room 101 was heated with Indoor.

Room 102 was the reference room during the measurement.

Room 101 interior image.

Reference room 102 interior image.

The temperature of the wall was measured with an IR thermometer.

Hotel manager Isabelle Persson and Sun King Pekka Wiena in reference room 102, at 12 noon after one hour of measurement. The temperature is the same as when the measurement started. 21.3 degrees at knee height and 21.8 degrees at head height.

Hotel manager Isabelle Persson and Sun King Pekka Wiena in measuring room 101, at 12 noon after one hour of measuring. The temperature is now 22.5 degrees at knee height (an increase of 1.2 degrees) and 22.9 degrees at head height (an increase of 1.6 degrees).

The temperature of the back wall increased by 1.7 degrees, the right wall by 1 degree, the left wall by 0.8 degrees and the ceiling by 1.7 degrees.

So Fullblack Indoor has created a significant temperature increase in one hour for only 2.4 cents!

It's always a good idea to have indoor walking during the day, regardless of the weather, in areas you don't go to on a daily basis. Even in very bad weather, the temperature increase in the exhaust hole is at least 1 degree, which means 20 W of power. Since the fan only draws 6 W, the heat gain is still 12 W. If there would be a whole day with heavy rain/snowstorm, there will be no difference in the outlet/inlet temperature, but since the adapter/fan only costs one penny in operation/hour, that day's "loss" will be negligible. When used in a residential environment such as an apartment or house, the Indoor is placed in the window in the morning when you go to work, and taken down when you return in the afternoon. Then you can choose the weather in which it is used.

Similarly, Indoor already benefits from the high airflow that circulates the air in the room/space, preventing mold growth and dehumidifying. So even on a snowstorm day, with no temperature increase, it is worth a penny an hour just to circulate the indoor air.

Plug the adapter from Fullblack Indoor into a lamp/day timer so that it runs only during the day.

Real-time measurement Indoor - 4th Feb 2023

On February 4, another test was carried out with reception manager Julien Leclerc. This time with only one indoor in the window and in light sunshine. The test started at 09.30 and lasted until 12.00. The same room was used, 101 with Indoor and 102 without. The starting temperatures in both rooms were 21.8 at head height and 21.5 at knee height. The heating was turned off in both rooms. Similarly, the rear ceiling/wall temperatures were similar, as close as 0.2 degrees.

After 2.5 hours, the temperature in room 101 had increased at head height to 23.6 and at knee height to 22.2. Rear ceiling/wall temperatures increased 1-1.3 degrees. Reference room 102 showed no temperature increase at any of the reference measurement points. Again, a tangible, significant heat gain thanks to Indoor – at a cost of just over three pennies…

Light sunshine when the measurement started.

The measurement took place in the same room 101 as the measurement on February 2nd. This time with 1 Fullblack Indoor and during 2.5h, between 09.30 and 12.00.

Starting temperature: 21.8 degrees at head height and 21.5 degrees at knee height.

The measurement ended at 12.00 and the reception manager Julien Leclerc of Quality Hotel Winn verifies that the temperature has risen to 23.6 degrees at head height (1.8 degrees increase) and 22.2 degrees at knee height (1.3 degrees increase).

Use a daytime thermometer to measure the temperature increase. Place the sensor as shown in the picture.