EP4074206A1

EP4074206A1 - System and method for personal thermal comfort

Info

Publication number: EP4074206A1
Application number: EP21168055.8A
Authority: EP
Inventors: Au ra Abraitien; Diana Kubilien; Martynas apurov; Aldas Dervinis; Vytautas Bleizgys; Algirdas Ba kys; Remigijus Bu as
Original assignee: State Research Institute Center For Physical Sciences And Technology
Current assignee: State Research Institute Center For Physical Sciences And Technology
Priority date: 2021-04-13
Filing date: 2021-04-13
Publication date: 2022-10-19
Anticipated expiration: 2041-04-13
Also published as: EP4074206B1; EP4074206C0

Abstract

A system for personal thermal comfort comprises a first and a second air blowers, thermoelectric elements, a first heatsink, a second heatsink, an exhaust conduit, one first framework of perforated 3D spacer textile channels for distribution of ambient air flow, one second framework of perforated 3D spacer textile channels for distribution of ambient, extra cooled, or heated air flow, an ambient air distribution valve.

The method of modifying a personal microclimate comprises using the first air blower for modification of temperature of the first heatsink, using a second air blower for modification of temperature of the second heatsink, using ambient air distribution valve for controlling ambient air flow to the first framework of perforated 3D spacer textile channels for distribution of ambient air flow for cooling and drying an area of a user's body, and to the second framework of perforated 3D spacer textile channels for distribution of ambient, extra cooled, or heated air flow for further cooling, extra cooling or heating an area of a user's body.

Description

Technical field

The invention relates to a system and a method for modification of personal microclimate conditions and in particular to a system and a method for personal thermal comfort for eliminating excess body heat by cooling and drying effects.

Background art

To ensure optimum body climate and protect a garment wearer against possible thermal shock under extreme conditions for example when wearing modern ballistic protection equipment, it is necessary to eliminate excess body heat by cooling and drying effects. A human body core temperature is typically ≈ 37 °C and during exercise and exposure to heat an increase of body core temperature more than 3 °C can cause overheating following by possible serious health problems (Havenith, G. Heat balance when wearing protective clothing. The Annals of Occupational Hygiene 1999, 43, 289-296).
Several systems reducing thermal barrier between protective clothing and human body, ensuring an optimal microclimate, are being developed (Yazdi, M. M., Sheikhzadeh, M. Personal cooling garments: a review. The Journal of The Textile Institute 2014, 105, 12: 1231-1250). Depending on technical solutions and cooling methods these systems are divided into two types: passive and active cooling systems. The most unsophisticated passive cooling system which could ensure satisfactory microclimate conditions is cooling of human body by inserting an additional layer of porous material or 3D textiles between wearers' body and clothing. Other techniques of passive cooling systems are based on use of PCM (Bendkowska W, K
onowska M, Kopias K, Bogdan A. Thermal Manikin Evaluation of PCM Cooling Vests. FIBRES & TEXTILES in Eastern Europe 2010; 18, 1 (78): 70-74) or shape memory polymers (Behl M, Lendlein A. Shape-memory polymers. Materials today 2007; 10; 4: 20-28), as well as on principle of evaporation cooling (Scott, R. A. (Ed.). Textiles for Protection 2005, Cambridge: Woodhead/The Textile Institute). Passive body cooling systems are effective only for a short time and during low physical activity. For active cooling systems, forced flow of cold liquid (usually water or a water-glycol mixture), or forced air flow is used (Vernieuw, C. R., Stephenson, L. A., Kolka, M. A. Thermal comfort and sensation in men wearing a cooling system controlled by skin temperature. Human Factors 2007, 49, 1033-1044).
Principle of air ventilation system is based on permanent air movement in vicinity of human skin by using a tube system or cooling zones formed by separators and elimination of heat excess through clothing openings (collar, armpits, torso). Different methods of air ventilation may be applied, as well as different systems which may be stationary or mobile (Chinevere, T. D., Cadarette, B. S., Goodman, D. A., et al. Efficacy of body ventilation system for reducing strain in warm and hot climates. European Journal of Applied Physiology 2008, 103, 307-314).
U. S. patent application no. 13/905,836 (publication No. US2013/0319031 ) describes a cooling unit that can be used with or without a garment, such as a ballistic vest, that covers a user's torso when worn. The cooling unit includes a fan for blowing ambient air; a manifold for distributing to the torso air that is blown by the fan; a hose for connecting the fan to the manifold. The manifold may be formed of three overlying panels that are secured together, including an outer panel, a central panel, and an inner panel that is closest to the user's torso when the cooling unit is being worn. Main disadvantage of such cooling system is that only ambient air can be used for cooling.
International patent application No. PCT/US2015/060955 discloses a heating and cooling arrangement comprising at least one integral low voltage heating and cooling source and an efficient flexible heat distribution means for distributing heat and cool across a surface. The arrangement may provide air flow through a fan which distributes air through an air splitting chamber. A low aspect ratio air moving design includes a thermoelectric module which is in thermal communication with a heat transfer block. As the ambient air transfers through air splitting chamber, it is directed via a conduit through an area for ventilation using ambient air and via a different conduit for interacting with the thermoelectric module for dissipating heat or cold to the surrounding. The main disadvantage of such system is that one area can be only cooled or heated using a thermoelectric element and the ambient air can only be supplied in an unmodified state to an area intended for ventilation. U. S. patent No. US 6,823,678 discloses a wearable air conditioner system that provides cooling or heating to a flexible material-based device incorporated into standard apparel such as shirts, pants, jackets, dresses, etc. The air system includes a ventilation portion located within a flexible material body, a thermoelectric module with heat exchangers on opposite sides, an air stream source, and a power source. The ventilation portion has two chambers formed between an inner layer made of a flexible material, an air delivery layer, and an outer layer made of flexible material with plurality of air vents in each of the flexible material inner and outer layers. Each of the heat exchangers is in fluid communication with one of the chambers. The air stream source provides air flow through the heat exchangers into the chambers and out through plurality of vent holes. The wearable air conditioner may optionally include a valve between the module air outflow ducts for selecting either the cooling mode of operation or the heating mode of operation. In the cooling mode the cool air stream is delivered through valve to hose while the hot air stream is passed through exhaust duct. In the heating mode, the hot air stream is delivered through valve to hose while the cool air stream is passed through exhaust duct. An alternative to using valve would involve directly connecting outflow duct to hose and directly exhausting outflow duct to the atmosphere. Main disadvantage of such Peltier effect-based system is high battery drain and increased risk of overloading the thermoelectric element. Another disadvantage of such a system is that only cooling mode or heating mode of operation is possible at a time using a thermoelectric element and a thermoelectric element is operational in all modes.
The present invention is dedicated to overcoming of the above shortcomings and for producing further advantages over prior art.

BRIEF DESCRIPTION OF THE INVENTION

Object of the present invention is a system and a method for personal thermal comfort for providing extra cooling or heating to a users' body part area for cooling and drying effect. The system for personal thermal comfort can be worn as a separate garment or in conjunction with another garment for example a ballistic vest or other protective garment (motorcyclists, industry workers, etc.). The system for personal thermal comfort comprises air blowers; a first framework of 3D spacer textile channels for ambient air distribution; a second framework of 3D spacer textile channels for distribution of ambient, extra cooled or heated air flow; thermoelectric elements producing the Peltier effect; heatsinks for dissipating heat and cold from relevant sides of the thermoelectric elements; at least one control valve for control of ambient air distribution in the second framework of 3D spacer textile channels for distribution of ambient, extra cooled or heated air flow; control units for control of the air blowers, a control unit for thermoelectric elements; a battery and optionally a battery charging module; temperature sensors.

BRIEF DESCRIPTION OF THE DRAWINGS

Features of the invention believed to be novel and inventive are set forth with particularity in the appended claims. The invention itself, however, may be best understood by reference to the following detailed description of the invention, which describes exemplary embodiments, given in non-restrictive examples, of the invention, taken in conjunction with the accompanying drawings, in which:

Fig. 1 shows a block diagram of the system for personal thermal comfort.
Fig. 2 shows an example of implementation of the system for personal thermal comfort in a vest.

Preferred embodiments of the invention will be described herein below with reference to the drawings. Each figure contains the same numbering for the same or equivalent element.

DETAILED DESCRIPTION OF THE INVENTION

It should be understood that numerous specific details are presented to provide a complete and comprehensible description of the invention embodiment. However, the person skilled in art will understand that the embodiment examples do not limit the application of the invention which can be implemented without these specific instructions. Well-known methods, procedures and components have not been described in detail for the embodiment to avoid misleading. Furthermore, this description should not be considered to be constraining the invention to given embodiment examples but only as one of possible implementations of the invention.
According to the preferred embodiment of the invention and as shown in Fig. 1, a system for personal thermal comfort comprises a ventilation device (1) comprising air blowers (1.1, 1.2) for ambient air supply into the system for personal thermal comfort, thermoelectric elements (3.1, 3.2, 3.3), such which produce the Peltier effect, for generating heat or cold on one side and for generating cold or heat on opposite side of each of the thermoelectric elements (3.1, 3.2, 3.3), a first heatsink (4.1) for facilitating heat or cold dissipation from the heat or cold generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), a second heatsink (4.2) for facilitating respectively cold or heat dissipation from the cold or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3).
The system for personal thermal comfort further comprises at least one first framework (5) of perforated 3D spacer textile channels (5.1, 5.2, 5.n) for distribution of ambient air flow for cooling and drying an area of a user's body, at least one second framework of perforated 3D spacer textile channels (6) for distribution of ambient, extra cooled or heated air flow for further cooling, extra cooling or heating an area of a user's body, an ambient air distribution valve (7) for controlling ambient air flow to the at least one first framework (5) of the perforated 3D spacer textile channels (5.1, 5.2, 5.n) and to the at least one second framework of the perforated 3D spacer textile channels (6), an exhaust conduit (8) for channelling the heated air from the ventilation device (1) and out of the system for personal thermal comfort, sensors (9.1, 9.2, 9.n) for measuring temperature of key areas of skin surface.
In all embodiments of the invention the channels (5.1, 5.2, 5.n, 6) comprise an inner layer of 3D spacer textile material which is incorporated into an outer layer of air non-permeable laminate textile material with sealed seams. The outer layer of the air non-permeable textile material comprises perforations formed on one side of the channels (5.1, 5.2, 5.n, 6) next to a users' body, hereby creating direct air flow to the body surface.
The system for personal thermal comfort further comprises an electronic control unit (10) comprising a battery (11) for powering the system for personal thermal comfort, a battery charging module (12) for charging the battery (11), a power distribution node (13) for distributing the power from the battery (11) to electric elements of the system for personal thermal comfort, a control panel (14) with a user interface to control system for personal thermal comfort, a Bluetooth module (15) for wireless data exchange with external devices, control units (16.1, 16.2) for the air blowers (1.1, 1.2).
The system for personal thermal comfort preferably comprises a first air blower (1.1) in fluid connection with the first heatsink (4.1), being in contact with the heat or cold generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), via a conduit (2.1) for modification of temperature of the first heatsink (4.1) by forcing the hot air to flow out of the system for personal thermal comfort via an exhaust conduit (8). Efficiency of the first air blower (1.1) should be at least 38 m³/h.
The system for personal thermal comfort further to the first air blower (1.1) preferably comprises a second air blower (1.2) in fluid connection with the second heatsink (4.2), being in contact with the cold or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), via a conduit (2.2) for relieving cold or heat from the surface of the extra cooling or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3) and for forcing the ambient, extra cooled or heated air to flow in the second framework of the 3D spacer textile channels (6) for distribution of ambient, extra cooled or heated air flow.
The second air blower (1.2) is used further for ambient air distribution through the first framework (5) of the perforated 3D spacer textile channels (5.1, 5.2, 5.n). For this purpose, the second air blower (1.2) is configured for gaining air pressure of at least 7.5 KPa for supplying air through the first and the second frameworks of the perforated 3D spacer textile channels (5.1, 5.2, 5.n, 6).
The perforated 3D spacer textile channels (5.1, 5.2, 5.n) of the first framework (5) are disposed in such a way so to essentially cover entire area for even ventilation with cooling and drying effect using ambient air only. The perforated 3D spacer textile channels (6) of the second framework are disposed between the centre 3D spacer textile channels (5.1, 5.2) of the first framework (5). Additional ambient air, extra cooled or heated air flow channel (6) is located in parallel to the user's body area where sweat intensity is the highest for example parallel to a user's spine.
Thermoelectric elements (3.1, 3.2, 3.3) are comprised of plurality of P-type and N-type thermoelectric couples, electrically connected in series between pair of thermally conductive substrates - heatsinks (4.1, 4.2). Application of a current through the thermoelectric elements (3.1, 3.2, 3.3) generates cold on one side and heat on another side. The heatsinks (4.1, 4.2) are in thermal contact with the cold generating surface and the heat generating surface and are positioned to receive an air flow there through. The heatsinks (4.1, 4.2) are designed hermetic - to achieve maximal transfer efficiency and to avoid air leakage to ensure sufficient air flow to the user. The performance efficiency of thermoelectric elements (3.1, 3.2, 3.n) is maintained by monitoring temperatures of hot and cold sides. Efficiency is strongly dependent on distinction between these two temperatures - the lower is distinction the higher is efficiency.
The exhaust conduit (8) is as short and as straight as possible to avoid air flow resistance to avoid overheating the thermoelectric elements (3.1, 3.2, 3.3).
The ambient air distribution valve (7) is proportional valve for supply air distribution between two channels. The valve is developed in such manner that overall air conductivity is equal to or greater than outlet of the second air blower (1.2). Servomotor is employed for valve (7) control and actual positioning.
The sensors (9.1, 9.2, 9.n) for measuring of temperature are used to obtain actual temperature of a user's skin surface while wearing a garment (18), for example a ballistic vest, in which the system for personal thermal comfort is integrated. For temperature measurement thermocouples should be used, as for example thermoresistors, have sufficient idle current leakage and low accuracy. Thermocouples also are very small in comparison to another sensors, therefore could be positioned directly on a desired measurement point.
The battery (11) for powering the system for personal thermal comfort is preferably a high energy density, rechargeable battery, or multiple batteries. The system for personal thermal comfort can also be powered by an alternative power source such as a 12V vehicle power plug whenever such a source is available. Only batteries with battery management system (BMS) including integrated overcurrent, voltage and temperature protection and charging control are considered proper for this application. Capacity of the battery should be at least 10Ah. For example, Li-Ion battery with integrated current controller.
The battery charging module (12), for charging the battery (11), is a Li-Ion battery charger, with accuracy of charging voltage of ± 0.1 V.
The power distribution node (13) is used for distributing of power from the battery (11) to electric elements of the system for personal thermal comfort. The power distribution node (13) should employ DC-DC step-down converters for control panel and Bluetooth module (15) power supply to minimise conversion losses. A current controller with current and voltage feedback should be used for power supply for the thermoelectric elements (3.1, 3.2, 3.3). This is due Volt Ampere dependencies of Peltier effect producing thermoelectric elements (3.1, 3.2, 3.3) - they are temperature dependent, therefore actual power consumption should be monitored for proper operation.
The control panel (14) with a user interface to control the system for personal thermal comfort is configured to control ventilation of a user's body part with cooling or heating and drying effect. As a human body has asymmetric dynamics, cooling and heating should be executed with different parameters. Therefore, PI controllers with variable coefficients could be employed. In such applications, coefficients of controller are not locked like in conventional PI controller but are dependent on monitored data and operation mode under certain law.
The Bluetooth module (15) for wireless data exchange with external devices is implemented for additional control and monitoring using any smart device such as a smartphone.
The control units (16.1, 16.2) of each of the air blowers (1.1, 1.2) are configured so that: the second air blower (1.2) provides at least 7.5 kPa pressure, blower speed could reach up to 34000 RPM. For this purpose, only brushless DC motor should be employed; and the first air blower (1.1) is a general purpose, voltage-controlled DC fan. PWM technique could be employed for proper control.
Control unit (17) of the thermoelectric elements (3.1, 3.2, 3.3) operates based on two main feedback parameters:

Temperature feedback receiving actual temperature of: an area of a users' body while wearing a garment (18), for example a vest; the thermoelectric elements (3.1, 3.2, 3.3); the 3D spacer textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks;
Operation current of each of the thermoelectric elements (3.1, 3.2, 3.3), implemented using Peltier control technique which is based on Peltier effect producing thermoelectric elements (3) current feedback. It must be implemented to keep performance efficient.

The system for personal thermal comfort can operate in ambient cooling mode, in cooling mode with extra cooling and in heating mode.
In ambient cooling mode the thermoelectric elements (3.1, 3.2, 3.3) are not active, the first air blower (1.1) does not operate and the second air blower (1.2) operates in combination with the ambient air distribution valve (7) in such a way that the air is allowed to flow only through the perforated 3D spacer textile channels (5.1, 5.2, 5.n) of the first framework (5), or only through the perforated 3D spacer textile channels (6) of the second framework, or through the perforated 3D spacer textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks. Splitting ambient air flow in two separate flows by the ambient air distribution valve (7) allows reducing power consumption of the system because extra air flow is being supplied only to the most demanding for cooling users' body part area in a more concentrated manner wherein the rest body part area intended for cooling is being supplied with ambient temperature air flow producing initial cooling effect, i.e. the cooling and drying effect is essentially enhanced and at least load on the second air blower (1.2) is reduced compared to cooling using only airflow forced through the perforated 3D spacer textile channels (5.1, 5.2, 5.n) of the first framework (5).
In cooling mode with extra cooling operation of the system for personal thermal comfort the first air blower (1.1) forces ambient air to flow through the first heatsink (4.1) which draws heat from the thermoelectric elements (3.1, 3.2, 3.3) operating in such a way that electric current passing therethrough forces the thermoelectric elements (3.1, 3.2, 3.3) to generate heat on its surface in contact with the first heatsink (4.1). The second heatsink (4.2) is subjected to cooling effect of the opposite side of the thermoelectric elements (3.1, 3.2, 3.3). The second air blower (1.2) forces ambient air flow through the air distribution valve (7) which allows to distribute air flow to the perforated 3D spacer textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks so that: first portion of ambient air having ambient air temperature is supplied to the perforated 3D spacer textile channels (5.1, 5.2, 5.n) of the first framework (5) for cooling of a part of a user's body using ambient air for cooling; second portion of ambient air is supplied to the second heatsink (4.2) to be cooled due to the cooling effect of the thermoelectric elements (3.1, 3.2, 3.3) having air temperature lower than that of the ambient air and is forced out of the second heatsink (4.2) to the perforated 3D spacer textile channels (6) of the second framework for extra cooling of a part of a users' body using air having temperature lower than that of the body part intended for cooling and lower than that of the ambient air.
Splitting ambient air flow in two separate flows by the ambient air distribution valve (7) allows reducing power consumption of the system for personal thermal comfort because extra cooled air is being supplied only to the most demanding for cooling users' body part area in a more concentrated manner than that of the ambient air wherein the rest body part area intended for cooling is being supplied with ambient temperature air producing initial cooling effect, i.e. load on the thermoelectric elements (3.1, 3.2, 3.3) is thus reduced (compared to cooling only using airflow forced through the thermoelectric elements (3.1, 3.2, 3.3)). The cooling effect is essentially enhanced compared with cooling by using only ambient air temperature air flow.
In heating mode operation of the personal microclimate modification system, the first air blower (1.1) does not operate. The second heatsink (4.2) is subjected to heating effect of the thermoelectric elements (3.1, 3.2, 3.3). The second air blower (1.2) forces ambient air flow through the air distribution valve (7) which allows to distribute air flow to the perforated 3D spacer textile channels (6) of the second framework so that heated air due to the heating effect of the thermoelectric elements (3.1, 3.2, 3.3) having air temperature higher than that of the ambient air is utilised for the body part area heating.
When the system for personal thermal comfort is used in combination with a garment (18), such as vest, the perforated 3D spacer textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks are attached to the inside mesh structure of the whole garment. The perforated 3D spacer soft textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks are attached through connecting hoses to the ventilation device (1).
The change in body, in particular - skin, temperature is recorded by thermocouples (9) located in the front, chest, and back area, and at the spinal canal. For example, skin temperature range is set to 34 - 36°C. When the upper temperature limit is exceeded, extra cooling is activated via the second framework of the perforated 3D spacer soft textile channel (6). The air blower (1.2) can generate a pressure of up to 7.5 kPa and supply an air flow of up to 15 m³/h.
Although numerous characteristics and advantages together with structural details and features have been listed in the present description of the invention, the description is provided as an example fulfilment of the invention. Without departing from the principles of the invention, there may be changes in the details, especially in the form, size and layout, in accordance with most widely understood meanings of the concepts and definitions used in claims.

Claims

System for personal thermal comfort comprising a ventilation device (1) comprising air blowers (1.1, 1.2) for ambient air supply into the system for personal thermal comfort, thermoelectric elements (3.1, 3.2, 3.3), such which produce the Peltier effect, for generating heat or cold on one side and for generating cold or heat on opposite side of each of the thermoelectric elements (3.1, 3.2, 3.3), a first heatsink (4.1) for facilitating heat or cold dissipation from the heat or cold generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), a second heatsink (4.2) for facilitating respectively cold or heat dissipation from the cold or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), the system for personal thermal comfort further comprises air distribution channels (5.1, 5.2, 5.n, 6) for supplying air to an area on a user's body, an exhaust conduit (8) for channelling the heated air from the ventilation device (1), sensors (9.1, 9.2, 9.n) for measuring temperature of key areas and an electronic control unit (10) for control of the operation of the system characterised in that the system for personal thermal comfort comprises:
a first framework (5) of perforated 3D spacer soft textile channels (5.1, 5.2, 5.n) for distribution of ambient air flow for cooling and drying an area of a user's body;

a second framework of perforated 3D spacer soft textile channels (6) for distribution of ambient, extra cooled, or heated air flow for further cooling, extra cooling or heating an area of a user's body;

an ambient air distribution valve (7) for controlling ambient air flow to the first framework (5) of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n) and to the second framework of the perforated 3D spacer soft textile channels (6);

a first air blower (1.1) in fluid connection with the first heatsink (4.1), being in contact with the heat or cold generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), via a conduit (2.1) for modification of temperature of the first heatsink (4.1);

a second air blower (1.2) in fluid connection with the second heatsink (4.2), being in contact with the cold or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), via a conduit (2.2) for relieving the cold or heat from the surface of the extra cooling or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3) and for forcing the ambient, extra cooled or heated air to flow in the second framework of the perforated 3D spacer soft textile channels (6) for distribution of ambient, extra cooled or heated air flow.
System according to claim 1 where the first framework (5) of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n) is disposed in such a way so to essentially cover entire area for even ventilation with cooling and drying effect using ambient air only and the second framework of the perforated 3D spacer soft textile channels (6) is disposed between centre 3D spacer soft textile channels (5.1, 5.2) of the first framework (5) of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n).
System according to any one of the previous claims where the 3D spacer textile channels (5.1, 5.2, 5.n, 6) of the first and the second frameworks comprises an inner layer of air permeable soft textile material and an outer layer of air non-permeable soft textile material, where the outer layer of the air non-permeable textile material is formed on the inner layer of the air permeable textile material and comprises perforations formed on one side of the channels (5.1, 5.2, 5.n, 6) next to a users' body.
System according to any one of the previous claims where efficiency of the first air blower (1.1) is at least 38 m³/h.
System according to any one of previous claims where the second air blower (1.2) is suitable to gaining air pressure of at least 7.5 KPa for supplying air through the first and second frameworks of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n, 6).
System according to any one of previous claims where the ambient air distribution valve (7) is proportional valve for supply air distribution between the first and the second frameworks of the perforated 3D spacer textile channels (5.1, 5.2, 5.n, 6) wherein overall air conductivity is equal or greater than outlet of the second air blower (1.2).
System according to claim any one of the previous claims wherein the electronic control unit (10) comprises:
a battery (11) for powering the system for personal thermal comfort;

a battery charging module (12) for charging the battery (11);

a power distribution node (13) for distributing the power from the battery (11) to electric elements of the system for personal thermal comfort;

a control panel (14) with a user interface to control the system for personal thermal comfort;

a Bluetooth module (15) for wireless data exchange with external devices;

control units (16.1, 16.2) for the air blowers (1.1, 1.2).
Method for modification of personal microclimate using a system for personal thermal comfort comprising air blowers (1.1, 1.2) for ambient air supply into the system for personal thermal comfort, thermoelectric elements (3.1, 3.2, 3.3), such which produce the Peltier effect, for generating heat or cold on one side and for generating cold or heat on opposite side of each of the thermoelectric elements (3.1, 3.2, 3.3), a first heatsink (4.1) for facilitating heat or cold dissipation from the heat or cold generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), a second heatsink (4.2) for facilitating respectively cold or heat dissipation from the cold or heat generating side of each of the thermoelectric elements (3.1, 3.2, 3.3), air distribution channels (5.1, 5.2, 5.n, 6) for supplying air to an area on a user's body, an exhaust conduit (8) for channelling the heated air from the ventilation device (1), sensors (9.1, 9.2, 9.n) for measuring temperature of key areas and an electronic control unit (10) for control of the operation of the system for personal thermal comfort characterised in that the system for personal thermal comfort is operating selectively in ambient cooling mode or cooling mode with extra cooling or heating mode wherein:
in cooling mode with extra cooling operation of the system for personal thermal comfort, a first air blower (1.1) forces ambient air to flow through the first heatsink (4.1) drawing heat from each of the thermoelectric elements (3.1, 3.2, 3.3), a second heatsink (4.2) is subjected to cooling effect of opposite sides of each of the thermoelectric elements (3.1, 3.2, 3.3), and a second air blower (1.2) forces ambient air flow through an air distribution valve (7) controllably distributing air flow to a first and to a second frameworks of perforated 3D spacer soft textile channels (5.1, 5.2, 5.n, 6) so that a first portion of ambient air having ambient air temperature is supplied to the first framework (5) of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n) for cooling of a part of a user's body using ambient air for cooling, second portion of ambient air is supplied to the second heatsink (4.2) to be cooled due to the cooling effect of the thermoelectric elements (3.1, 3.2, 3.3) having air temperature lower than that of the ambient air and is forced out of the second heat sink (4.2) to the second framework of the perforated 3D spacer soft textile channels (6) for extra cooling of a part of a users' body using air having temperature lower than that of the body part intended for cooling and lower than that of the ambient air;

in ambient cooling mode each of the thermoelectric elements (3.1, 3.2, 3.3) is inactive, the first air blower (1.1) does not operate and the second air blower (1.2) operates in combination with the ambient air distribution valve (7) in such a way that the air is allowed to flow only through the first framework (5) of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n) or only through the second framework of the perforated 3D spacer soft textile channels (6) or through the first and the second frameworks of the perforated 3D spacer soft textile channels (5.1, 5.2, 5.n, 6);

in heating mode operation of the system for personal thermal comfort the first air blower (1.1) does not operate, the second heatsink (4.2) is subjected to heating effect of each of the thermoelectric elements (3.1, 3.2, 3.3), the second air blower (1.2) forces ambient air flow through the air distribution valve (7) directing air flow to the second framework of the perforated 3D spacer soft textile channels (6) so that heated air due to the heating effect of the thermoelectric elements (3.1, 3.2, 3.3) having air temperature higher than that of the ambient air is utilised for the body part area heating.