Curtain wall with variable heat transfer coefficient

Abstract

A curtain wall or roof element, with built in solar panel or heat absorbing layer, and at least one blower for air circulation inside the enclosed device, one or more temperature sensors monitoring the temperature inside and outside the device and a microcontroller activating the blower according to predetermined program to heat or cool the room enclosed by the device. If solar cells or panels are used they will generate electrical power and heat. It is the purpose of this invention to increase the energy harvesting coefficient from the sun's radiation by utilizing the absorbed heat for increasing the temperature in a space enclosed by said device, moreover the smart configuration of the curtain wall will enable to change the system's isolation characteristics by changing its U values. U value of a curtain wall describes the heat isolation characteristics of the device in a numerical form.

Claims

1. A glass curtain wall or skylight module, comprising of: at least two hermetically sealed cavities; an outer transparent surface facing towards the sun light; at least one inner partially light absorbing plane at a distance in the direction of the incident light, creating a space, between front transparent surface and absorbing plane; at least one additional surface facing towards an enclosed area or a room placed at a distance from partially light absorbing plane; an enclosure element enclosing the outer perimeter of the space created by inner and outer transparent surfaces; at least one fan or blower capable to circulate enclosed air inside each said hermetically sealed cavity; temperature sensors to independently control the fan activities and the heat transfer U-Value of said glass curtain wall or skylight module; and mounting elements for assembling the module into said building skylight or curtain wall.

2. The glass curtain wall or skylight module of claim 1, wherein the partially light absorbing plane incorporates solar cells, which generate heat to be selectively removed by forced air circulation.

3. The glass curtain wall or skylight module of claim 1 wherein the said fans or blowers are operated from remote by wireless means or by a microcontroller programmed to activate said fans or blowers according to temperature readings.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) The invention will be explained in detail below with the aid of the enclosed drawings. It shows the following:

(2) FIG. 1 is a graphical representation of the Heat Transfer Coefficient behavior vis-a-vi the flow rate dictated by built-in fans.

(3) FIG. 2 is an exploded view of the proposed curtain wall device with its built-in absorbing layer, excluding the air-circulating fans.

(4) FIG. 3 is a cross section of one possible embodiment, where two longitudinal axial fans are mounted on each cavity, providing the necessary circulating capability independently.

(5) FIG. 4 is yet another cross section of an additional embodiment, with two longitudinal axial fans mounted in a different layout.

(6) FIG. 5A is a cross section of an embodiment with centrifugal blowers, two on each cavity.

(7) FIG. 5B is a front view of the embodiment with centrifugal blowers.

DETAILED DESCRIPTION

(8) FIG. 1 shows a graphical representation of Heat Transfer Coefficient of an enclosed cavity with air circulation inside the cavity. The heat transfer coefficient changes significantly with the circulation magnitude. Axis 101 describes the heat transfer coefficient where axis 102 describes the air circulation magnitude. The resulting heat transfer coefficient is represented in a graphical mode 103 showing that with no air flow it is about 0.25 W/(m.sup.2K) and will increase above tenfold for high circulation rates exceeding 3 W/(m.sup.2K).

(9) FIG. 2 is a complete module consisting of 2 outside and inside glass panels denoted as 201 encapsulating a solar panel or heat absorbing panel denoted as 202, and having an external perimeter frame denoted as 203.

(10) FIG. 3 is a schematic representation of the proposed curtain wall module consisting of two inner and outer window elements denoted as 301, a heat absorbing or solar cell module in between creating two airfield cavities 302. The cavities are preferably hermetically sealed. Sun direction denoted as 307 penetrates through the glass surface and is absorbed by solar or heat absorbing elements 305. The 305 element is heated up and also starts generating electricity in the case of solar cells. For managing the accumulated heat in 305, the two tubular fans denoted as 303 are independently activatedwhen the fan facing the sun direction is activated the circulation of the cavity facing the sun will increase and most of the heat will be expelled to the outside since the heat transfer coefficient of this cavity is going to be high, thus heat will flow freely from 305 to the outer face. Accordingly, if the fan facing the interior is activated then the heat transfer coefficient between 305 to the inner part increases significantly, thus most of the accumulated heat will be transferred to the interior. The elements denoted as 304 represent the hermetically sealing elements disposed on the periphery of cavities, usually composed of specialty glue with built-in humidity absorbers. The arrows denoted as 306 represent air flow direction caused by 303 fans. The downwards arrow represents sucked air by 303 element, and the upwards arrow represents the blowing direction of air upwards, this will cause circulation within the hermetically sealed cavity. This circulation will increase heat transfer between the two bordering panels, significantly changing the U-Value of the cavity in the horizontal direction. According to temperature sensors and a heat target of the interior, the fans will be activated to best meet this target. For example: in wintertime, when member 305 has a higher temperature than the interior, then the fan facing the interior will be activated to transfer heat into the room. Contrary to that, in summertime the excessive heat will be expelled out, preventing unnecessary heat into the interior. Moreover, according to temperatures in and out, even without direct sun exposure the system can conduct heat in and out the interior by controlling the curtain wall heat transfer coefficient.

(11) FIG. 4 is yet another embodiment with slight mechanical variation compared to FIG. 3, in order to create more room for the axial fans. In this figure, encapsulating windows are denoted as 401, the heat absorbing layer is denoted as 405 and the perimeter mechanical cross section denoted as 404 is modified to accept the larger fan denoted as 403. A special member denoted as 402 will separate the circulating air input\output directions.

(12) FIG. 5A is the side view of a cross section of yet another embodiment using centrifugal blowers denoted as 501 and 502. Each cavity has two centrifugal blowers arranged at the corners.

(13) FIG. 5B is a front view of this embodiment showing air circulation in front and back cavities. Air suction direction in back cavity is shown by 503 and air suction direction in front cavity is shown by 504. Accordingly, expelled air direction is shown as 505 for back cavity and as 506 for front cavity.

(14) The features of the invention disclosed in the specification, in the drawings and in the claims can be essential for implementation of the invention, both individually and in any combination.