WO1990005880A1

WO1990005880A1 - Ventilation apparatus

Info

Publication number: WO1990005880A1
Application number: PCT/FI1989/000209
Authority: WO
Inventors: Jorma METSÄ-KETELÄ
Original assignee: Metsae Ketelae Jorma
Priority date: 1988-11-15
Filing date: 1989-11-14
Publication date: 1990-05-31
Also published as: SE8903824L; FI885280A0; FI885280A; SE8903824D0

Abstract

A ventilation apparatus which comprises a fan (2), a heat recovery unit (3), exhaust-air and inlet-air openings (4, 5) oriented towards the room space, and air-flow baffles (34, 35). The ventilation apparatus is made up of an oblong, tall, cupboard-like casing, known per se, in which the exhaust-air opening (4) is located in the upper section of the casing and the inlet-air opening (5) over a considerably larger surface area below the exhaust-air opening (4).

Description

Ventilation apparatus

The present invention relates to a ventilation apparatus, which comprises a fan, a heat recovery unit, openings for exhaust air and inlet air, and air-flow baffles. The venti¬ lation apparatus is intended primarily for the ventilation of a room space and for the recovery of heat, especially in industrial halls and other relatively large room spaces.

In industry, it was previously very common to ventilate by means of rooftop extraction fans. The replacement air was provided for the room space by means of a separate inlet air device in which the inlet air was also heated. The system was simple and easy to install and economical as regards its acquisition cost. However, it had the disad¬ vantages of a high supply voltage and high energy con¬ sumption.

A method common today for the ventilation of industrial halls and other large room spaces is to equip the building with a central ventilation apparatus, which usually com¬ prises, in addition to exhaust-air and inlet-air fans, also filters and an after-heating radiator for the inlet air. Almost without exception, a heat recovery device is also included.

Ventilation ducts lead from the central apparatus to the different parts of the building. The ducts for their part are equipped with air distribution means through which the inlet air and the exhaust air are led into the room space and out of it. This present-day system for its part has the advantages of a low supply voltage and low energy consump¬ tion.

It is common in modern ventilation systems to use, as air distribution means, inlet-air means operating according to the principle of displacement ventilation. Displacement ventilation is a method in which vitiated exhaust air is removed from the room space through the upper section of the room. Clean inlet air for its part is led to the lower section of the room. In this manner, a zone of clean air is produced in the room within the zone in which people breathe, whereas a zone of vitiated air is formed close to the ceiling.

According to studies, ventilation thus implemented is four times more efficient than conventional mixing ventilation.

In order for the ventilation system to function properly according to this principle, the temperature of the inlet air must be lower than the room temperature, at maximum equally high.. In that case the inlet air will, by gravity, settle in the lower section of the room, forming there ^"a zone of clean air.

According to certain recommendations, the temperature of the inlet air in industry may be no more than six degrees lower than the room temperature. On the other hand, in office rooms it may be no more than three degrees lower than the room temperature.

The introduction of air cooler than the room temperature directly into the zone in which people breathe requires separate arrangements. The air-flow rate must be suffi¬ ciently low in order to avoid producing detrimental draft. In practice this means a high frontal surface of the inlet- air means.

The old systems had the advantages of a simple structure, low acquisition cost, and ease of installation. Their disadvantages were a high supply voltage and high energy consumption.

The newer system for its part has the advantages of a low supply voltage and low energy consumption.

Respectively, its acquisition cost is, of course, higher. Its further disadvantages include a complicated structure and complicated installation of the system, and the inflex¬ ibility of the apparatus when the use of the building and the ventilation requirement change.

It is the object of the present invention to eliminate the disadvantages mentioned above. The ventilation apparatus according to the invention is characterized in that the ventilation apparatus is made up of an oblong, tall, cupboard-like casing in which the exhaust-air opening is located in the upper section of the casing and the inlet- air opening over a much larger surface area below the exhaust-air opening. One of the most important advantages of the apparatus according to the invention is that the ventilation apparatus includes the fans, heat recovery, ventilation ducts, filters, and air distribution means advantageously in the same unit. Thus the installation of the apparatus is simple.

By using the ventilation apparatus according to the inven¬ tion it is possible rapidly to adjust the rate of air change as the load changes. The apparatus can, when neces¬ sary, be dismounted. Or several apparatuses may be in¬ stalled according to need.

Such needs often arise, especially on rental premises in which it is necessary to be able to adapt the building flexibly for different uses. Another important advantage is that the apparatus according to the invention operates advantageously according to the so-called displacement ventilation principle.

One embodiment of the invention is characterized in that the baffles are made up of sheets which are mounted by their upper edges on bearings and move freely under air flows; owing to pressures prevailing inside the ventilation apparatus they automatically direct the exhaust air and the inlet air to the correct openings. Thus there is no need for separate control devices or motors, which are part of almost all ventilation apparatuses known per se.

Another embodiment of the invention is characterized in that the exhaust-air opening is close to the ceiling of the room space and the inlet-air opening extends from the lower edge of the exhaust-air opening all the way to the floor of the room space. Thus the vitiated exhaust air in the upper ^ection of the room is withdrawn directly from the upper section of the room, and clean inlet air can be introduced into the lower part of the room at a sufficiently low in¬ flow speed.

The invention is described below with the aid of examples, with reference to the accompanying drawings, in which

Figure 1 depicts diagrammatically a ventilation apparatus capable of being installed against a wall, with the appara¬ tus standing up and the principal components shown detached from each other.

Figure 2 depicts the ventilation apparatus installed against a building wall, with the apparatus standing up.

Figure 3 depicts the ventilation apparatus, with the appa¬ ratus functioning as an extraction apparatus. Figure 4 depicts the ventilation apparatus, with the appa¬ ratus functioning as an air inlet apparatus.

Figures 5 - 7 depict a variant of the apparatus according to the invention, in which the apparatus is connected to the outer air via the roof. Usually two equally large appa¬ ratuses are installed in one room space, one functioning as an extraction apparatus, in accordance with Figure 3, and the other one as an air inlet apparatus, in accordance with Figure 4.

Both of the apparatuses are equipped with fans 2 changing their flow direction. When the fans change their flow di¬ rection, the apparatuses reverse their functions so that the apparatus which has functioned as an extraction appara¬ tus becomes an air inlet apparatus and the apparatus which has functioned as the air inlet apparatus becomes an ex¬ traction apparatus.

In this manner, the air flows are channeled to travel re¬ ciprocally via energy storage units, whereby a regenerative energy recovery process is accomplished.

The energy of the exhaust air is transferred, with high efficiency, to the inlet air.

Inside the recovery unit.3 there are installed a exhaust- air baffle 34 and an inlet-air baffle 35 to direct the air flows in such a way that the apparatus will function advan¬ tageously according to the displacement ventilation princi¬ ple. To implement this, the apparatus is made tall in such a manner that the exhaust air A is taken from the upper section of the room, usually at a level of at minimum 2 meters, whereas the inlet air D is directed to the lower section of the room. The baffles 34 and 35 function by means of the pressure produced by the fans 2:

When the machine is not operating, in accordance with Fig¬ ure 2, the baffles are closed, preventing, outside the operating time, air flow by gravity through the apparatus.

When the apparatus is functioning as an extraction appara¬ tus in accordance with Figure 3, the vacuum produced by the fans 2 inside the apparatus closes the inlet-air baffle 35, whereupon there is no air flow through the inlet-air filter 5.

The vacuum produced by the fans opens the exhaust-air baffle 34, whereupon the exhaust air A passes through the exhaust-air filter 4 into the recovery unit 3. When flowing through the energy storage unit 32, the exhaust air yields, with high efficiency, the energy present in it to the energy storage unit.

When the apparatus is functioning as an air inlet apparatus according to Figure 4, the overpressure produced by the fans 2 inside the apparatus presses the exhaust-air baffle shut, whereupon there is no flow of air through the exhaust-air filter 4.

Claims

1. A ventilation apparatus comprising a fan (2), a heat recovery unit (3) , exhaust-air and inlet-air openings (4, 5) oriented towards the room space, and air-flow baffles (34, 35), characterized in that the ventilation apparatus is made up of an oblong, tall, cupboard-like casing, known per se, in which the exhaust-air opening (4) is located in the upper section of the casing and the inlet-air opening (5) is located over a considerably larger surface area below the exhaust-air opening (4).

2. A ventilation apparatus according to Claim 1, charac¬ terized in that the baffles (34, 35) are made up of sheets, mounted by their upper edges on bearings and moving freely under air flows, the sheets, under the pressures prevailing inside the ventilation apparatus, automatically directing the exhaust air (A) and the inlet air (D) to the correct

_^openings (4,5).

3. A ventilation apparatus according to Claim 1 or 2, characterized in that the exhaust-air opening (4) is lo¬ cated close to the ceiling (8) of the room space and the inlet-air opening (5) extends from the lower edge of the exhaust-air opening (4) down to the floor (10) of the room space.