VENTILATION UNIT

Abstract

A ventilation unit (1) is formed by at least one fan (2), a heat exchanger, axially spaced from the fan (2), and a housing (3). The housing (3) has a first housing section (4), with a constant flow cross-section, where the heat exchanger is arranged. A second housing section (5) adjoins the first section (4) in the axial flow direction. The fan (2) is arranged on the second housing section (5) in the axial flow direction. During operation, the fan conveys air through the heat exchanger, arranged in the first housing section (4), and through the second housing section (5). The flow cross-section of the second housing section (5) is reduced in the flow direction from the first housing section (4) to the fan (2) by an adaptation to the form of housing wall sections (6, 6′) of the second housing section (5).

Claims

1.-14. (canceled)

15. A ventilation unit comprising: at least one fan, a heat changer, arranged axially spaced from the fan, and a housing, the housing has a first housing section and a second housing section. The first housing section has a constant flow cross-section where the heat exchanger is arranged, the second housing section, adjoins the first section in the axial flow direction; the fan is arranged at the second housing section and, in operation, the fan conveys air through the heat exchanger, arranged in the first housing section, and through the second housing section; the flow cross-section of the second housing section is reduced in the flow direction from the first housing section to the fan by an adaptation of a shape of housing wall sections of the second housing section.

16. The ventilation unit according to claim 15, wherein the second housing defines an intake chamber for the at least one fan and a flow can freely pass through the intake chamber.

17. The ventilation unit according to claim 15, wherein the second housing section includes an outflow-side axial wall closing the housing an axial opening is formed in the outflow-side axial wall and the at least one fan is arranged, placed, onto the axial wall at the axial opening.

18. The ventilation unit according to claim 15, wherein at least the first housing section is formed rectangularly with two different side lengths and an intake diameter of the at least one fan facing the heat exchanger is smaller than each side length of the rectangular first housing section.

19. The ventilation unit according to claim 15 wherein the housing wall sections of the second housing section are formed in sections running obliquely towards an axis of rotation of the at least one fan.

20. The ventilation unit according to claim 15 wherein flow inserts are arranged in the second housing section, the flow inserts are formed in sections running obliquely towards an axis of rotation of the at least one fan and reduce the flow cross-section of the second housing section in the direction of the at least one fan.

21. The ventilation unit according to claim 20, wherein the flow inserts are perforated guide plates and a cavity, formed between the housing and the guide plates, is filled with sound-absorbing material.

22. The ventilation unit according to claim 18 wherein a ratio of an axial length of the second housing section with respect to the intake diameter of the at least one fan is specified in a range such that 0.2≤C/D≤0.5.

23. The ventilation unit according to claim 18 wherein the housing is formed rectangularly with two different side lengths, and a ratio of the side lengths to the intake diameter of the at least one fan is specified in a range such that
1.1≤(X,Y)/D≤2.0, in particular 1.2≤(X,Y)/D≤1.8.

24. The ventilation unit according to claim 17 wherein two or more fans are arranged axially parallel to one another on the axial wall of the second housing section.

25. The ventilation unit according to claim 17 wherein the fan has a fan housing that determines the intake diameter.

26. The ventilation unit according to claim 25 wherein the intake diameter of the fan housing has a size identical to the axial opening of the axial wall of the second housing section.

27. The ventilation unit according claim 15 wherein the housing wall sections of the second housing section each extend along a plane.

28. The ventilation unit according to claim 15 wherein the housing wall sections of the second housing section each have a curved profile shape.

Description

DRAWINGS

[0021] FIG. 1 is a side schematic view of an exemplary embodiment of a ventilation unit;

[0022] FIG. 2 is a front schematic view of the exemplary embodiment of the ventilation unit according to FIG. 1;

[0023] FIG. 3 is a top schematic view of the exemplary embodiment of the ventilation unit according to FIG. 1;

[0024] FIG. 4 is a schematic view of an alternative exemplary embodiment of a ventilation unit;

[0025] FIG. 5 is a diagrammatic view of the sound power plotted over the volume flow of the ventilation unit according to FIG. 1;

[0026] FIG. 6 is a diagrammatic view of the sound level plotted over the frequency of the ventilation unit according to FIG. 1.

DETAILED DESCRIPTION

[0027] In FIGS. 1-3, an exemplary embodiment of a ventilation unit 1 is shown in a side view, front view, and top view. The ventilation unit 1 includes a housing 3 formed by a first housing section 4 and a second housing section 5 directly adjoining the first housing section 4 in the axial flow direction. The fan 2 is attached to the second housing section 5. The heat exchanger (not shown) is arranged in the first housing section 4. Alternatively, a housing section of the heat exchanger can also form the first housing section 4 of the housing 3. The first housing section 4 and the directly adjoining front part of the second housing section 5 have the same rectangular cross-sectional shape with the two side lengths X, Y and thus form a constant flow cross-section. In the second housing section 5, the housing wall sections 6, 6′ run inclined along a plane towards the axis of rotation of the fan 2. Thus, this reduces the flow cross-section of the second housing section 5 in the flow direction towards the fan 2. However, as an alternative embodiment, which is not shown the housing wall sections 6, 6′ do not extend rectilinearly along a plane but, at least in sections, in an arcuate shape towards the fan 2. The second housing section 5 provides an intake chamber for the fan 2 through which a flow can pass in an unobstructed manner and where the intake air is guided via the housing wall sections 6, 6′ in the direction of the fan 2.

[0028] The axial end of the housing 3, facing the fan 2, is closed with the axial wall 7 where the axial opening 9 is provided axially centrally, where the fan 2 is arranged. In operation, the fan 2 sucks air through the housing 3 and thus through the heat exchanger and blows it out axially. The fan 2 includes a fan wheel 11 arranged in the fan housing 8. The fan housing 8 is formed in the shape of a nozzle and determines the intake diameter D on the intake side that is identical to the diameter of the axial opening 9 of the axial wall 7, but is smaller than the side lengths X and Y. According to the embodiment shown in FIG. 2, the ratio X/D=1.2 and the ratio Y/D=1.3. As an alternative to an axial fan, a diagonal fan is used in a further embodiment.

[0029] In FIG. 4, an alternative exemplary embodiment of the ventilation unit 1 is shown in top view comparable to FIG. 2. All the features disclosed for the exemplary embodiment according to FIGS. 1-3 also apply accordingly to FIG. 4, except that two fans 2, 22 are arranged parallel to each other.

[0030] In FIG. 5, the advantage with regard to the sound power SWL [dB] plotted over the conveyed volume flow V [m.sup.3/h] of the ventilation unit 1, shown in FIGS. 1-3, is illustrated in a diagram. The sound power of the ventilation unit 1 is illustrated by the curve 200, a comparison product without the configuration of the second housing section 5 according to the disclosure is illustrated by the curve 100. Correspondingly, FIG. 6 shows the two curves of the ventilation unit 1 (curve 200) and the comparison product (curve 100) with respect to the sound pressure SPL [dB] plotted over the frequency f [Hz]. In both diagrams according to FIGS. 5 and 6, the noise reduction is clearly detectable over the entire progression of the volume flow V and the frequency f. In particular, at high volume flow rates, the sound power level is reduced considerably.

[0031] Referring again to FIGS. 1-3, in addition to the embodiment shown, modifications in the size ratios are comprised by the scope of the disclosure. The side lengths are determined in a range 0.5<X/Y<2. The dimensioning of the housing wall sections 6, 6′ and the extent drawn in towards the fan 2 with respect to the available installation space of the housing 3 is determined by the sizes a, b, c in relation to the sizes A, B and C. Preferably, the sizes a, b and c are smaller than the installation space sizes of the housing determined by A, B and C by a factor α, β and γ, such that a=αA, b=βB and c=γC, where 0<α,β,γ≤1.

[0032] Preferably, the factors α, β and γ and thus the geometry of the housing wall sections 6, 6′ are designed with respect to the intake diameter D of the fan 2 such that

[00001]$0.2.Math.D\le C\le 0.5.Math.D$$\alpha \ge 0.4\mathrm{and}y\ge 0.3\mathrm{for}0.1.Math.D\le A\le 0.3.Math.D$$\beta \ge 0.4\mathrm{and}y\ge 0.3\mathrm{for}0.1.Math.D\le B\le 0.3.Math.D$$\alpha \ge 0.2\mathrm{and}y\ge 0.25\mathrm{for}0.3.Math.D\le A\le 0.5.Math.D\beta \ge 0.2\mathrm{and}y\ge 0.25\mathrm{for}0.3.Math.D\le B\le 0.5.Math.D$

In a further variant, the length extent c is determined with respect to the lengths a, b such that

[00002]$\hspace{1em}\begin{array}{cc}\delta \ge I.Math.y+J& \mathrm{for}0\le y\le 0.5\\ \delta \ge K& \mathrm{for}0.5<y\le 1\\ \mathrm{.Math.}\ge I.Math.y+J& \mathrm{for}0\le y\le 0.5\\ \delta \ge K& \mathrm{for}0.5<y\le 1\end{array}$

Wherein

[0033] [00003]$ϵ=a\tan \left(\frac{b}{c}\right)\mathrm{and}\delta =a\tan \left(\frac{a}{c}\right)$

The values for I, J and K are:
I=−200; J=120 and K=20. In addition, 0<δ, ε≤90°. With the size ratios given in these ranges, the advantageous flow effects for solving the object described above can be achieved. The specified size ratios expressly apply not only to the exemplary embodiment shown in FIGS. 1-3, but generally also to the second housing section 5.

[0034] The foregoing description of the embodiments has been provided for purposes of illustration and description. It is not intended to be exhaustive or to limit the disclosure. Individual elements or features of a particular embodiment are generally not limited to that particular embodiment, but, where applicable, are interchangeable and can be used in a selected embodiment, even if not specifically shown or described. The same may also be varied in many ways. Such variations are not to be regarded as a departure from the disclosure, and all such modifications are intended to be included within the scope of the disclosure.