HuksefluxUSA - Model TCOMSYS01 Hot Cube -Thermal Comfort Measuring System

• direct representation of the human body
• helps understand and quantify the detailed physical cause and effect of thermal comfort
• simple experiments can be used to quantify the sources of heat gain or loss
• offers directional information
• good addition to Wet-Bulb Globe temperature measurement
• robust, student-proof
• “stand-alone”; equipped with its own clock and memory
• safe, low voltage power supply
• communication by (virtual) Ethernet link
• user interface program on MCU

TCOMSYS01 was originally designed to study the effect of radiation sources on human comfort. Equipped with heat flux sensors that measure in 5 directions and a humidity and temperature probe, it offers a good picture of energy gains and losses from all sides to a metal body that thermally resembles the human body; the TCOM01 sensor is in essence a miniature thermal mannequin.

The TCOMSYS01 system employs dedicated sensors and electronics, measuring thermal comfort according to the new Hot Cube method.
The high accuracy of the MCU (Measurement and Control Unit) ensures that TCOMSYS01 will still measure down to very low heat fluxes. The MCU has a robust aluminum housing. The system generates a measurement file, including a time-stamp. The measurement data are stored in the MCU and are later downloaded to a PC. The user is responsible for data analysis.

The primary source of information from TCOMSYS01 simply is the power [W] required to keep the TC0M01 sensor at a constant temperature; a very direct measure of human comfort. This power may be compared to the power required at 20 °C ambient air temperature, no convection (zero wind speed), and no radiation. Power consumption will immediately show if there is a situation of overheating or heat stress or a situation of overcooling or cold stress.

The second direct information supplied by the heat flux sensors of TCOMSYS01 is the heat loss or gain [W/m2] as a function of direction. If radiative sources are dominant, TCOMSYS01 will measure radiative asymmetry.

To study the exact effect of radiative sources, in many cases a simple experiment, like switching a radiation source [on] and [off] or shielding a radiation source, can be used to distinguish between convective and radiative heat transport.

Far-infrared radiation sources may be studied by temporary shielding with a silicon wafer. Silicon has around 50 % transmission. Radiation from the sun or lamps may be quantified by shading and unshading.

To study the insulating effect of clothing, TCOM01 may be insulated using the same fabrics.

A web browser may be used for real-time measurement review, data collection, and for changing control settings such as TCOM01 body temperature.

Already in 1929 the Eupatheoscope (from Greek “wellbeing–emotion–examination”) was designed by A.F. Dufton to quantify the condition in a room from the point of view of comfort. It consists of a blackened cylinder that is controlled to maintain a temperature of 23 °C. The power used is interpreted in terms of equivalent temperatures.

In 1990 the company Bruel & Kjear carried a thermal comfort meter (model 1212), based on the same principle, in addition to processing Fangers equation.

Both models involved only an integrated power measurement. The new Hot Cube method improves on this by incorporating omnidirectional heat flux measurements.

The main contributors to thermal comfort are air temperature, airspeed, radiant temperature, and humidity. Apart from this, there are personal contributors such as metabolic rate and insulation by clothing.

Many studies use Fanger’s thermal comfort equation as applied in EN ISO 7730: Moderate Thermal Environments – Determination of the PMV and PPD indices and specification of the condition for thermal comfort. Another approach utilizes a globe temperature measurement: EN ISO 27243: Hot environments. Estimation of the heat stress on working man, based on the WBGT Index (Wet Bulb Globe Temperature).

These methods are quite indirect in particular when determining the heat flow from airspeed and radiation.

• TCOMSYS01 offers heat flux measurements. This approach is a lot more direct than the indirect estimate from airspeed and radiation.
• TCOMSYS01 offers directional information.
• TCOMSYS01 works at a realistic skin temperature of 33 °C (user adjustable).

TCOMSYS01 is designed to work between +10 and +25 °C. In its standard configuration, uninsulated and stabilized at 33 °C, it is rated for operation in indoor conditions including significant radiative heating.

It will stabilize at 33 °C under approximately one of the following conditions:

• air speeds < 5 m/s
• irradiance < 400 W/m2
• ambient air temperature > 5 °C

Under other conditions, the sensor may not be able to stabilize its body temperature due to overheating (indicating overheating or heat stress) or shortage of electrical power (indication of overcooling or cold stress). Powered using a low voltage, TCOMSYS01 is safe to use.

TCOMSYS01 may be used for short-term outdoor experiments in the order of weeks. Under long-term exposure to solar radiation, the black heat flux sensor coating may become more reflective.

• Measurand : heating power for stabilization, heat flux (5x), ambient air temperature, relative humidity, TCOM01 body temperature
• TCOMSYS01 specifications : :
• TCOM01 temperature setting : 33 °C (user adjustable)
• Included cable : 2 x cable with 2 connectors (1.5 m)
• Standard rated operating temperature range : +10 to +25 °C
• Limiting temperature range : – 25 to +50 °C
• Required data analysis : To be performed by the user
• Data display : in web browser
• Start up interval : < 10 min
• TCOM01 specifications : :
• Weight : 1.12 kg
• Temperature sensor : 10 kΩ thermistor
• IP protection class : IP65
• Mounting : tripod with ¼ inch -20 UNC screw; a Manfrotto Pixi EVO 2-section tripod is included
• MCU specifications : :
• User interface : on MCU as a web page
• Connection : via LAN or “Ethernet over USB”
• Voltage measurement accuracy : 4 x 10-6 V (0.8 W/m²)
• Rated power supply voltage : 10 to 16 VDC
• Adapter power supply : 100 – 240 VAC, 50/60 Hz
• Rated operating temperature range MCU : – 25 to +50 °C
• Data storage capacity : 2GB; > 1 year of data
• Options : TCOM01 sensor only
• extended rated operating conditions; temperature, irradiance, wind speed