EP1044346B1 - Method at ventilation systems and arrangement for distributing air to room units - Google Patents

Abstract

The present invention relates to a method in ventilation systems with separate branch conduits (6) to each room to be vented to distribute air to the rooms in flows adequately adapted for each of the separate room. The invention is characterized in that the air to each of the separate rooms are fed by branch conduits (6) having a flexible cover permitting a non rectilinear laying in a system of joists and in walls, and being connected to one or several air distributing centrals (5) wherein means (7) are used for an individual adjustment of the flow of air to each separate branch conduit (6) emerging in the rooms through inflow means (8) with a pressure drop being low compared to the pressure drop in the conduit (6) relating to friction losses.

Description

The present invention relates to a method in ventilation systems and to an arrangement for distributing air to room units. Such a method and arrangement is known by EP-A-184 887.

In conventional ventilation systems the air is distributed to each room by branch conduits connected to one or serveral main conduits. The flow of air to each room is adjusted by individual settings of the inflow means of the rooms. The inflow means in rooms close to the input of the main conduit have to be throttled pretty hard to stop these rooms from having a too big flow of air compared to rooms situated further down the main conduit. Such a throttling will often cause a disturbing noise.

The individual settings and adjustments of each room to a desired flow of air is difficult and time-consuming to obtain as each adjustment in one room will influence the flows of the rest of connected rooms. To obtain a desired balance the adjustments and the settings have to be carried out in several steps. Nevertheless, after a final balancing of the system the set balance can be altered by resetting the inflow means in any of the rooms to reduce draught or to improve the ventilation.

The main object of the present invention is to easily create possibilities for an simple installation of a venting system having a prearranged basic setting of the necessary air flow to each room unit.

Another object of the invention is to disclose a method for calculating the whole ventilation system regarding needed or desired air change for each room unit included in the system.

Yet another object of the present invention is to disclose a method using a computerized calculating program with a simulating capacity in connection to the dimensioning of venting system in which priority can be done for perfect ventilation in certain room units and for different loads and during different conditions.

Another object of the present invention is to obtain a ventilation system which is easy to install alsor for non-skilled workers.

Yet another object of the present invention is to obtain a venting technique in which flow meters are arranged in each flow channel to each room unit and where flow measure data from the flow meters are collected in a central microprocessorized control unit, which, regarding to the changes in some or any of the flow amounts in the flow channels, will calculate which changes in the settings of the throttle means in all of the flow channels will give the best achievable ventilation regarding priority and comfort.

Another object with the present invention is obtain a ventilating technique being used both with an over pressure in the inflow means and with a self-draught in the outflow means, wherein an automatic throttling of the flow in the outflow means will take place by an increasing chimney action, which throttling occcurs by inserting a heat exchanger element in the outflow channel(s).

The above mentioned objects are obtained by a method and by an arrangement having the characterizing clauses mentioned in the claims.

By having the branch conduits to the separate rooms equipped with a flexible casing and to have these conduits connected to one or several air distributing centrals with devices for an individual adjustment of the air flow to each separate branch conduit and as these conduits emerge in the room with a pressure drop being low compared to the pressure drop caused by friction in the conduit, an adjustment and setting of the flow amount to each room unit for each of the air distributing branch conduit can take place in connection to the distributing channel, which means that the branch conduit can emerge in the room unit without any throttling, i.e. all pressure drop will be in the conduit(s) and not in the inflow means or in valves in connection to each room unit. Hereby conduits of different size and/or numbers can be arranged from the distributing central to each room unit. This can be taken care of already at the installation of the system according the invention as the knowledge regarding the amounts of air needed to obtain a satisfactory ventilation/air exchange of each room unit is known in advance. The numbers of branch conduits is also known as well as the length of each separate branch conduit included in the system which means that the pessure drop in each branch conduit is calculated from the necessary flow to each room unit. By having the possibility to gradually throttle the flows at the distributing central at each floor by using throttle means, a complete solution regarding the numbers of branch conduits to each room, in view of the length of each branch conduit, will e.g. state as follows: "1,8 branch conduits to the bath-/washing room unit on the second floor", which means that one fully open branch conduit + a 20 % throttled branch conduit shall be used for this room unit. This calculation and also the installing instructions will be recieved with the delivery of the venting system. This means that also non-skilled workers can install the system. In the simplest application of the invention any change or adjustment does not need to be done after installation. The installation will in its entirety work very satisfying.

Thus, in a ventilation system according to the invention the air is distributed to the different rooms by branch conduits connected to a distributing central. The ventilation system accordning to the present invention includes inflow means with insignificant pressure drop compared to the pressure drop in the branch conduit, i.e. the resistance of the channel. Thus an accurate calculation of the air distribution in the system can be performed with knowledge of the desired air flow to each room together with knowledge of the length of the branch conduit.

The distributing centrals according to the invention have been provided with adjustable throttling means in each connection for branch conduits, which, when knowing the pressure drop characteristics of the throttling means and the length of the branch conduit, will, from the very beginning, allow a final adjustment/setting of the air flow to each room. This adjustment is calculated in advance. Thus the ventilation system according to the invention can be adjusted and balanced without any measuring of the air flow or pressure drops in the system.

However in a more sophisticated application of the invention there is a better possibility to perform an effective ventilation with a proportionately simple low powered structure having a low sound level in certain preferred room units, while other secondary room units in certain conditions will have a less effective change of air. In a variant of the invention a greater portion of the capacity of the ventilation system can be used to increase the air flow in a space used as a drying cabinet or room.

According to the invention it is also simple to complete a basic design of the ventilation system according to the invention, i.e. with permanently preinstalled adjustment means for each room unit, with a microprocessor equipped control unit and with air flow sensors in each air distributing conduit by arranging the wiring for these sensors already in the basic design of the system.

The invention will now be described in connection to the enclosed drawings; where

Fig. 1 is a diagrammatic view of a conventional ventilation structure; and where

Fig. 2 is a diagrammatic view of a ventilation structure workning according to the invention.

In fig. 1 a blower means or a distributing central 1, a main conduit 2 and branch conduits 3a, 3b, 3c and 3d together with inflow means 4a, 4b, 4c and 4d are shown. At this plant most of the pressure drop is normally in the inflow means, which very easily will cause a disturbing noise. The adjusting of the air distribution has to be done by checking all the inflow means and performing measures of pressur drops and air flows repeadetly to have a well balanced plant.

At the plant according to the invention - fig. 2 - there are blower means or a distributing central 5 with branch conduits 6a, 6b, 6c, 6d and 6e together with throttle means 7a, 7b, 7c, 7d and 7e as well. Furthermore there are inflow means 8a, 8b, 8c, 8d och 8e. At this plant the pressure from the distributing central 5 is essentially constant. The desired air flow can be adjusted for each rooom with knowledge of the flow-/pressure drop characteristics of the branch conduits 6 and of the corresponding characteristics of the throttling means 7. The pressure drop in the non-adjustable inflow means 8 is insignificant. All of the adjustments can be performed at one position and without any measurings. In bigger plants there can be larger systems according to fig. 2 where several distributing centrals 5 are connected to blower means. Often the main conduit between the differnt distribution centrals 5 have such big aera that the pressures in the different distribution centrals 5 are almost the same. This will simplify the calculations for distribution and adjustments.

Claims (9)

1. A method in a ventilation system with separate branch conduits (6) to each room to be vented for distributing the air to the rooms in flows adequately adapted for each room, by one or several air distributing centrals having means to be used for an individual adjustment of the flow of air to each separate branch conduit characterized in that the air to each of the separate rooms is fed by branch conduits (6) having a flexible cover permitting a non rectilinear laying in a system of joists and in walls, and emerges into the rooms through inflow means (8) with a pressure drop being low compared to the inherent pressure drop in the conduit (6) relating to friction losses, whereby said individual adjustment of the flow of air is performed by throttling means.
2. A method according to claim 1, characterized in that the distributing central(s) (5) is (are) equipped with adjustable means (7) in connection to the separate branch conduits (6), which adjustable means (7) will be given a basic setting in connection to the installing of the ventilation system, and which basic setting is calculated with the aid of a calculating program.
3. A method according to claim 2, characterized in that the set positions of the adjustable means (7) are activated by a central controlling unit having a microprocessor and a soft ware being unique for the current ventilation system with the marginal conditions and priorities being established regarding blower capacity, lenths of conduits, and need of ventilation for the different room units.
4. Ventilation system with separate branch conduits to each separate room to be vented, for distributing the air to the rooms in flows adequately adapted for each room, wherein said branch conduits are connected to one or several air distributing centrals having means to be used for an individual adjustment of the flow of air to each separate branch conduit, characterised in that said branch conduits have a flexible cover, permitting a non rectilinear laying in a system of joists and in walls, that inflow means, through which air emerges into said separate rooms, have a pressure drop being low compared to the inherent pressure drop in the conduit relating to friction losses, and that said means to be used for individual adjustment of the flow of air comprise throttling means.
5. Ventilation system as claimed in claim 4, characterized in flow meters arranged in each air flow conduit in the ventilation system, in a central microprocessor equipped controlling unit arranged to recieve signals from the flow meters indicating the current flows in each brach conduit, wherein a changing of the settings of the adjustable means (7) will take place, when needed for a comfortable or a priority point of view.
6. Ventilation system according to claim 5, characterized in that heat exchanger means are arranged in the evacuation means at each room unit and in outflow conduits connected thereto to collect the heat energy in the outflowing air.
7. Ventilation system according to claim 6, characterized in that the heat exchanger means also is used as evaporating means in an air dehumidfier and that the room unit is used as a drying room for laundry.
8. Ventilation system as claimed in claim 4, wherein said distributing central (A, B) is adapted for performing the method of any one of claims 1-3 and further comprises an outer connecting case, preferably of a plastic material with several adaptors for the branch conduits, and where adjustable means (7) for flow control are arranged at each adaptor.
9. Ventilation system according to claim 8, characterized in a microprocessor equipped control unit recieving signals from a flow meter in each branch conduit and which, according to an established program schedule, will activate the adjustable means (7) to re-establish the desired ventilation in the room units as far as possible.

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