GB2234809A - Ventilation systems - Google Patents

Abstract

A heat exchange assembly for exchanging heat between an inlet flow of fresh air induced by a fan (3) and an outlet flow passing through a heat pump 14 comprises a plurality of pipes (1) arranged so that the area (2) contained within them forms a duct for the air travelling in the opposite direction. Cones or obstructions (7) are placed within the area (2) causing the air to pass out through the gaps between the pipes (1) into hollow collars 8. The collars pass the air back through the gaps and onto the next set of cones/obstructions. The gaps are defined by spacers. When the pipes pass through a partition wall 6 to the area requiring ventilation, the collars and cones. A band (11) may pass around the exterior of the pipes. Each pipe may be suspended from an individual wire. <IMAGE>

Description

HEAT EXCHANGE VENTILATION SYSTEM This invention relates to a combined heat exchange and ductwork ventilation system.

Ventilation systems for buildings requiring a high turnover rate (eg industrial buildings because of chemicals or swimming pools because of humidity) have presented a problem which has so far resulted in the use of high power fans and large heat exchanger batteries. Both of which are expensive to install, run, and maintain.

This invention incorporates a direct air to air heat exchange system with the ductwork, producing an efficient method of circulating large amounts of air with minimal energy cost. Smaller power farts can be used with this system, as the air need no longer be filtered and pushed through banks of baffles and heat exchangers. The system comprises of two main sections, the first section in which the air is totally contained within the ductwork as it passes through the plant room and areas not requiring high ventilation. The second section is the ductwork as it passes through the building in which the high ventilation rate is required.

The invention also includes a method by which the system.can be manufactured and installed.

A specific embodiment of the invention will now be described by way of example with referance to the accompanying drawings in which: Figure 1. A section down through the formation of intake pipes showing the area contained becoming the extract duct.

Figure 2. A perspective view of one spacer used to obtain the correct gaps between the pipes.

Figure 3. A sectional plan of the first stage of the ventilation ductwork, passing through the plant room and unventilated areas.

Figure 4. Shows a distribution plan of the air intake pipes in the ventilated building.

Figure 5. Shows a schematic view of how the system can be constructed and supported.

The system is best described in two sections: Section 1. In which the totally enclosed ductwork passes through the unventilated section of the building. The cold fresh air is drawn into the ductwork by the fan 3 where it passes over a mainfold, dividing the air into a plurality of pipes 1. The pipes are arranged so that the area contained within them 2 is capable of conveying the extract air. Therefore the sum of the cross sectional areas of the pipes 1 must be compatable to the cross sectional area contained within them 2 to give a balanced intake/extract of air.

In this section the extract duct 2 is filled with cones or suitable shaped obstructions 7, nose to nose, back to back. These have the effect of pushing the extract air out of the area 2 through gaps in the pipes and into hollow collars 8. The collars are placed adjacent to the pairs of cones and have the effect of forcing the air in and out through the gaps in the intake pipwork.

The sum of the gaps between the pipes 8 multiplied by the height of a cone must be compatable to the cross sectional area 2 so as to give a balanced flow through the ductwork.

The number of cones are determined by the length of the plant room and the temperature/humidity differance acceptable between the intake and exhaust air. A method of draining the bottom of the hollow collars is incorporated to remove any condensate as a result of the heat exchange process. A heat pump recovery coil 14 can be added to the system to improve the efficiency further.

Section 2. In this section the pipework in the ventilated building or area is described (fig. 4).

The arrangement of pipes 1 is maintained as it passes through the plant room or dividing wall 6. But the gaps between the pipes 8 are adjusted so that an even volume of air is drawn into the area 2 over the entire length of the ductwork system. Therefore the sum total of all the gaps between the pipes 8 multiplied by the length of the pipework 9 must be compatable to the cross sectional area 2.

Pipes branch off to supply fresh air to the entire building 4, as the pipes branch off the cross sectional area 2 is reduced maintaining the correct gap to ensure an even return of exhaust air 5 down the entire length 9 of the duct. Baffles may be required with some systems to ensure this gap returns a proportional amount of air as the pipes branch off 4. For example in fig. 5 the sum of the air gaps between the 16 pipes shown would be made compatable with the sum of the air gaps between the 8 pipes further down the system.

In buildings of high humidity for example swimming pool halls, a drip tray will have to be incorporated below the main trunking to collect condensate from the heat exchange process.

Both the extract and intake fans can be reversable so that double the quantity of fresh air can be pushed into or removed from the building by opening windows and doors when heat recovery is not required on hot days.

Method of Manufacture.

This method applies to both the enclosed, non ventilated section and the ductwork passing through the ventilated building.

Two plates 13 are firmly fixed at the ends of the building between which the ventilation pipes are to run. Holes are drilled in the plates and support wires 12 are stretched between the plates. The wires are positioned in such a manner that they are above the centre of gravity of the fixed pipes. Thus allowing each pipe 1 to be suspended from its own individual wire.

To achieve the correct air gap spacers 10 are used in conjunction with a band 11 passing round the exterior of the pipes. The band 11 can be fixed to the fabric of the building for additional support.

With the non ventilated section of pipework (fig. 3) it would be convenient to site the band and spacers at a point between the hollow collars 8 which would then allow the collars to be held into place by the bands.

An example of the materials to use would be stainless steel flue liner for the intake ducts and glass fibre to produce the cones and hollow collars. UPUC or similar for the spacers and stainless steel for the bands. The plates 13, possibly on the outside of the building, treated mild or galvanised steel.

Claims (6)

1 A combined ventilation/heat exchange ductwork in which a plurality of pipes are arranged so that the area contained between them becomes the means for conveying the air in the opposite direction to the air in the said pipes.

2 As in claim 1 where part or all the ductwork is fitted with cones or obstructions and exterior collars to cause the air to have maximum contact with the pipes.

3 As in claim 1 where the gaps between the pipes are adjusted to give an even return of air down the length of the system in the ventilated building.

4 As in claim 1 & 2 where the gaps between the pipes are adjusted to give optimum and even flow through the multitude of cones/obstructions and collars.

5 A taught wire support system for the pipes enabling thin pipework to be used.

6 A combined ventilation ductwork substantially as described herein with referance to Figures 1 to 5 of the accompanying drawings.

6 As in any previous claim where the gaps are maintained with spacers and bands, the bands also acting as an additional method of support.

7 A combined ventilation ductwork substantially as described herein with referance to Firures 1 - 5 of the accompanying drawings.

Amendments to the claims have been filed as follows 1 A two part combined air to air heat exchange and ductwork ventilation system in which: Part A Consists of an enclosed heat exchanger and ductwork combined, passing through rooms or areas not requiring high ventilation rates.

The heat exchanger ductwork consists of a plurality of pipes whose combined air carrying capacity is capable of conveying the volume of intake air to the area requiring high ventilation rates.

The plurality of pipes are arranged so that their axis are substantially parallel to each other, in a circle or other suitab]e shape. The area thus created by the arrangement of pipes thus becomes the extract duct.

Gaps are left between each pipe, and cones or suitable shaped obstructions are placed nose to nose, back to back in the extract duct created by, the pipes. Hollow collars are placed around the plurality of intake pipes adjacent to each pair of cones. The combined effect of the cones and hollow collars effectively forces the air in and out through the gaps in the pipes, maximizing the contact of air with the pipes.

Part B Consists of a heat exchanger and ductwork comt,jried passing through areas requiring high ventilation rates. The plurality oF pipes described in (i) passes through to the ventilated area, the cones (or obstructions) and hollow collars are abseit in this section. The gaps between the plurality of intake pipes are adjusted to give the optimum or even return of air down the length of the duct. Pipes branch off at intervals down the ductwork to supply air to all areas, the return air being drawn back through the gaps in this section of pipework.

2 As in claim 1 where the direction of air flow is reversed, the intake effectively becoming the extract and visa-versa.

3 As in claim 1 where the heat exchange action is cancelled by reversing one of the air flows, tllus using the entire ductwork to supply or extract only. Moving air through the building for a cooling effect on hot days.

4 A ventilation ductwork system as in claim 1 where only section i or section ii is utilised on its own.

5 As in any previous claim where the gaps between the pipes are maintained with spacers and bands, the bands also can act as a method of support.