Patent Description:
Heat recovery ventilation units are designed such that one inlet must be connected with outdoor air while the other inlet must be connected with extract air and likewise for the two outlets being connected to the supply airstream and exhaust airstream.

This makes the individual heat recovery ventilation unit less versatile as it has a single configuration. Thereby, one type of heat recovery ventilation unit must be produced for each different configuration - the most common being where the purpose of each inlet is reversed.

This complexity increases if the heat recovery ventilation unit must have a bypass for bypassing the polygonal heat exchanger or if the outdoor air must pass an internal pre-heater.

The complexity persist along the entire supply chain until the heat recovery ventilation unit has been installed as the person installing a heat recovery ventilation unit must know the system design such that the correct heat recovery ventilation unit is sent to the installation site.

<CIT> describes ventilating system having a heat exchanger. The ventilating system includes a case having a first flow passage for guiding outdoor air to a room, and a second flow passage for guiding room air to an outside of the room. The ventilating system further includes a bypass flow passage on one side of the case for bypassing the heat exchanger, a first damper for opening/closing the inlet space, a second damper for opening/closing the air discharge space, and a third damper for opening/closing the bypass flow passage.

Thus, there is a need for a heat recovery ventilation unit which can be used in several different configurations according to the ventilation system design.

It is an object of the invention to provide a heat recovery ventilation unit defining a first airstream pathway and a second airstream pathway where the heat recovery ventilation unit is on-site configurable, such that both the first airstream pathway and the second airstream pathway can be used for outdoor air/supply airstream and extract air/exhaust airstream.

It is an object of the invention to provide an airstream swap unit for controlling an airflow pathway through a heat recovery ventilation unit, thereby controlling whether an airflow shall enter a polygonal heat exchanger or bypass the polygonal heat exchanger.

It is an object of the invention to provide a pre-heater sub-assembly. The pre-heater sub-assembly enabling that the first airstream pathway and the second airstream pathway can be used for preheating of outdoor air.

An object of the invention is achieved by a heat recovery ventilation unit according to claim <NUM>. In particular, the heat recovery ventilation unit comprises a polygonal heat exchanger and a housing substantially formed by insulation material. The polygonal heat exchanger and the housing define.

The housing further comprises a bypass channel arranged to bypass the polygonal heat exchanger along the first airstream pathway, thereby defining a bypass airstream pathway. The heat recovery ventilation unit further comprises an airstream swap unit downstream to the polygonal heat exchanger and the bypass airstream pathway. The airstream swap unit is configurable between.

The first airstream pathway and the airstream pathway are named the first and second instead of outdoor air/supply airstream and extract air/exhaust airstream since the first airstream pathway may be the outdoor air/supply airstream or extract air/exhaust airstream and the second airstream pathway may be the outdoor air/supply airstream or extract air/exhaust airstream depending on the specific on-site installation.

Neither the first nor the second is more preferred, however throughout this application first airstream is connected to the bypass airstream pathway. The bypass airstream pathway can be used irrespective of whether the airstream is an outdoor air/supply airstream or an extract air/exhaust airstream.

The airstream swap unit is configured to swap between the bypass airstream pathway and the first airstream pathway such that heat recovery can be avoided when heat recovery is unwanted.

The housing formed by insulation material may have an outer wall with a thickness and a λ-value which together equals a U-value lower than <NUM>.

The heat recovery ventilation unit has a backside adapted to be mounted against a wall, a frontside opposite to the backside, a topside and a bottom side defined relative to gravity vector, and a right and left side defined in a direction from the frontside to the backside.

The heat recovery ventilation unit is a negative pressure heat recovery ventilation unit as air will enter the inlets and the polygonal heat exchanger due to a negative pressure.

According to the invention, the airstream swap unit comprises a stationary grate and a slidable grate, the grates comprise a series of complementary apertures at a bypass section facing the bypass channel and at an exchanger section facing a side of the polygonal heat exchanger, wherein the apertures are offset between the bypass section and the exchanger section, wherein.

Thereby, it is only necessary to slide or displace the slidable grate to change the airstream swap unit between the heat recovery position and the bypass position. As the apertures are offset between the bypass section and the exchanger section.

The stationary grate is preferably positioned upstream to slidable grate and downstream to the polygonal heat exchanger as this configuration reduces risk of leak flow between the first airflow path and the bypass airflow path.

The skilled person would understand that the grates may be grids, where the grids form the complementary apertures.

In an aspect, the stationary grate may comprise between the exchanger section and bypass section a block part arranged to prevent leak flow.

The risk for leak flow is high between the sections and especially on the side of the stationary grate as the of the stationary grate is upstream relative to the slidable grate and the pressure is lower at the side of the slidable grate.

Thus, the block part will prevent leak flow especially when engaging either part of the housing or part of the polygonal heat exchanger.

In an aspect, the block part may extent substantially along a frontside or a backside of the polygonal heat exchanger.

Tests have shown that by extending along either the frontside or the backside of the polygonal heat exchanger then the block part reduces the risk of leak flow is lowered significantly.

In an embodiment, the block part may extent into the bypass channel and substantially along a frontside or a backside of the polygonal heat exchanger.

In an aspect, the airstream swap unit comprises an actuator adapted for displacing the slidable grate. There the position of the slidable grate is configurable by simple controlling the actuator.

In an aspect, the actuator is connected to the bypass section.

When the first airstream pathway is used for extract air/exhaust airstream then condensation will be generated downstream to the polygonal heat exchanger i.e. at the stationary grate and the slidable grate and the condensation will thus form at or on the actuator. This will over time damage the actuator, thereby increasing operation costs.

This can be counteracted simply by connecting the actuator to the bypass section as the actuator at that position will be unaffected by condensation.

In an aspect, the polygonal heat exchanger forms a side of the bypass channel.

Thereby, the depth of the heat recovery ventilation i.e. the distance between the frontside and backside of the heat recovery ventilation unit can be reduced by the polygonal heat exchanger forming a side of the bypass channel.

Furthermore, since the polygonal heat exchanger forms a side of the bypass channel then the bypass channel becomes accessible by simply removing the polygonal heat exchanger as shown in <FIG>.

In an aspect, the heat recovery ventilation unit comprises a first ventilator downstream to the polygonal heat exchanger along the first airstream pathway, and a second ventilator downstream to the polygonal heat exchanger along the second airstream pathway.

The first and second ventilators will generate a negative pressure upstream to the first and second ventilators and a positive pressure downstream.

In an aspect, the heat recovery ventilation unit comprises.

The different manifolds enable the same heat recovery ventilation unit to be used in a plurality of different configurations as the two or more inlets/outlets enable various configurations.

In an aspect, the first outlet manifold comprises a first outlet next to the first ventilator, and/or the second outlet manifold comprises a second outlet next to the second ventilator.

In an aspect, one or more of the two or more inlets and/or the one or more of the two or more outlets are partially carved into the housing.

Thereby, the technician can easily modify the heat recovery ventilation unit on-site in accordance with the requirements of the ventilation system.

In an embodiment, at least one of the partially carved inlets and/or at least one of the partially carved outlets may be formed by a groove.

The technician may in this case cut the inlet or outlet by inserting a knife in the groove and follow the groove.

In an aspect, the heat recovery ventilation unit may comprise a first filter upstream to the polygonal heat exchanger and the bypass channel along the first airstream pathway, and a second filter upstream to the polygonal heat exchanger along the second airstream pathway.

Thereby the airstreams are filtered by the filters.

In an aspect, the heat recovery ventilation unit may comprise.

wherein the pre-heater sub-assembly comprises a heater element, a heater element holder having an upper and a lower flexible part extending from opposite ends of the heater element holder, the upper and lower flexible parts are arranged to be wedged between sides of the housing.

In many cases, the heat recovery ventilation unit will have an inlet close to a backside of the heat recovery ventilation unit and an inlet close to a frontside of the heat recovery ventilation unit. A pre-heater sub-assembly can easily be installed along the second airstream pathway where the inlet is close to the front side. See <FIG> for a situation where it is easy to install a pre-heater sub-assembly.

However, it is more difficult to install a pre-heater sub-assembly along the first airstream pathway. However, the flexible parts enable the pre-heater sub-assembly to be wedged between sides of the housing. The pre-heater sub-assembly can be installed or replaced along the first airstream pathway by removing a filter and the polygonal heat exchanger, then wedging the pre-heater sub-assembly between sides of the housing where the spring force of the flexible parts secures the positioning.

The first flexible part may comprise a bent defining a foot adapted to engage a slit formed in the housing.

In an aspect, wherein heat recovery ventilation unit may comprise a controller configurable such that both the first airstream pathway and the second airstream pathway can be used for outdoor air/supply airstream and extract air/exhaust airstream.

In an embodiment, the stationary grate may comprise between the exchanger section and the bypass section a block part arranged to prevent leak flow.

In an embodiment, the block part may be adapted to extent substantially along a frontside or a backside of the polygonal heat exchanger during use.

In an embodiment, the actuator is connected to the bypass section to avoid formation of condensation on the actuator.

Embodiments of the invention will be described in the figures, whereon:.

<FIG> illustrates a heat recovery ventilation unit <NUM>. <FIG> discloses the heat recovery ventilation unit <NUM> from a top view while <FIG> discloses the heat recovery ventilation unit <NUM>.

The heat recovery ventilation unit <NUM> is shown as a schematic in <FIG>, and <FIG> show individual parts of the heat recovery ventilation unit <NUM> without a front on a frontside <NUM> and at different cross-sections.

The heat recovery ventilation unit <NUM> comprises a first inlet <NUM> and a first outlet <NUM> defining a first airstream pathway <NUM> from the first inlet <NUM> to the first outlet <NUM> through a polygonal heat exchanger <NUM> (not shown in <FIG>) and a second inlet <NUM> and a second outlet <NUM> defining a second airstream pathway <NUM> from the second inlet <NUM> to the second outlet <NUM> through the polygonal heat exchanger <NUM>.

The shown heat recovery ventilation unit <NUM> has open inlets <NUM>, <NUM> and outlets <NUM>, <NUM> at a topside <NUM> and partially carved inlets <NUM>' (not shown but present on a right side <NUM>), <NUM>' and partially carved outlets <NUM>', <NUM>'(not shown but present on a right side <NUM>). Furthermore, a bottom side <NUM> comprises carved outlets <NUM>", <NUM>" along with a first condensation outlet <NUM> and a second condensation outlet <NUM> for removal of condensation.

The configuration could be different such as the topside <NUM> having partially carved inlets <NUM>, <NUM> and outlets <NUM>, <NUM>.

The heat recovery ventilation unit <NUM> comprises a controller <NUM> configurable such that both the first airstream pathway <NUM> and the second airstream pathway <NUM> can be used for outdoor air/supply airstream and extract air/exhaust airstream. This is also the reason for two condensation outlets <NUM>, <NUM>.

The heat recovery ventilation unit <NUM> further comprises a first filter <NUM> and a second filter <NUM>.

<FIG> illustrates a schematic of a heat recovery ventilation unit <NUM>.

The heat recovery ventilation unit <NUM> comprises a polygonal heat exchanger <NUM> and a housing <NUM> substantially formed by insulation material.

The polygonal heat exchanger <NUM> and the housing <NUM> define a first inlet <NUM> and a first outlet <NUM>, which define a first airstream pathway <NUM> from the first inlet <NUM> to the first outlet <NUM> through the polygonal heat exchanger <NUM>, and a second inlet <NUM> and a second outlet <NUM> defining a second airstream pathway <NUM> from the second inlet <NUM> to the second outlet <NUM> through the polygonal heat exchanger <NUM>.

The housing <NUM> further comprises a bypass channel <NUM> arranged to bypass the polygonal heat exchanger <NUM> along the first airstream pathway <NUM>, thereby defining a bypass airstream pathway <NUM>.

The heat recovery ventilation unit <NUM> comprises an airstream swap unit <NUM> downstream to the polygonal heat exchanger <NUM> and the bypass airstream pathway <NUM>. The airstream swap unit <NUM> comprises a bypass section <NUM> facing the bypass channel <NUM> and at an exchanger section <NUM> facing a side of the polygonal heat exchanger <NUM>. The airstream swap unit <NUM> being configurable between a heat recovery position <NUM>, where the bypass airstream pathway <NUM> is blocked, and a bypass position <NUM>, where the first airstream pathway <NUM> is blocked.

The heat recovery ventilation unit <NUM> comprises a first filter <NUM> upstream to the polygonal heat exchanger <NUM> and the bypass channel <NUM> along the first airstream pathway <NUM> to filter the airstream during use.

The heat recovery ventilation unit <NUM> comprises a second filter <NUM> upstream to the polygonal heat exchanger <NUM> along the second airstream pathway <NUM> to filter the airstream during use.

The heat recovery ventilation unit <NUM> comprises a first ventilator <NUM> downstream to the polygonal heat exchanger <NUM> along the first airstream pathway <NUM> and downstream to the airstream swap unit <NUM>. The heat recovery ventilation unit <NUM> comprises a second ventilator <NUM> downstream to the polygonal heat exchanger <NUM> along the second airstream pathway <NUM>.

The first ventilator <NUM> and the second ventilator <NUM> generate a negative pressure upstream to the ventilators <NUM>, <NUM> and a positive pressure downstream to the ventilators <NUM>, <NUM>.

The first inlet <NUM> forms part of a first inlet manifold <NUM> with two or more first inlets <NUM>, <NUM>' forming part of the first airstream pathway <NUM> upstream to polygonal heat exchanger <NUM>.

The first outlet forms part of an outlet manifold <NUM> with two or more first outlets <NUM>', <NUM>" forming part of the first airstream pathway <NUM> downstream to polygonal heat exchanger <NUM>. T first outlet manifold <NUM> comprises a first outlet <NUM>" next to the first ventilator <NUM>.

The second inlet <NUM> forms part of a second inlet manifold <NUM> with two or more second inlets <NUM>, <NUM>' forming part of the second airstream pathway <NUM> upstream to polygonal heat exchanger <NUM>.

The second outlet <NUM> forms part of a second outlet manifold <NUM> with two or more second outlets <NUM>, <NUM>', <NUM>" forming part of the second airstream pathway <NUM> downstream to polygonal heat exchanger <NUM>. The second outlet manifold <NUM> comprises a second outlet <NUM>" next to the second ventilator <NUM>.

The heat recovery ventilation unit <NUM> may comprise a single pre-heater sub-assembly <NUM> upstream to the polygonal heat exchanger <NUM> and the bypass channel <NUM> along the first airstream pathway <NUM>, or a heating element <NUM> upstream to the polygonal heat exchanger <NUM> along the second airstream pathway <NUM>. The figure shows two pre-heater sub-assemblies <NUM> however this is to illustrate that the single pre-heater sub-assembly <NUM> can be positioned at both positions.

In theory one could have two pre-heater sub-assemblies <NUM>, however then the extract air/exhaust airstream would be heated before being exhausted to the ambient atmosphere causing increases in a power or heating costs without any positive effect.

The pre-heater sub-assembly <NUM> is positioned upstream to the first/second filter <NUM>, <NUM>, however a reverse positioning is possible.

<FIG> illustrates a heat recovery ventilation unit <NUM> without a front side. Thus <FIG> shows how the heat recovery ventilation unit <NUM> would be view by a technician removing the front side making a polygonal heat exchanger <NUM>.

In the present setup a topside <NUM> comprises a first and second inlets <NUM>, <NUM> and first and second outlets <NUM>, <NUM>.

The cross-sections X-X are shown in <FIG>, which discloses the housing <NUM> formed substantially of insulation material.

<FIG> illustrates cross-section A-A of <FIG>. The first airstream pathway <NUM> and the second airstream pathway <NUM> is marked with arrows.

The first and second filters <NUM>, <NUM> are partially shown. The filters <NUM>,<NUM> can be installed/removed by simply sliding the filters into/out of the housing <NUM>.

In this illustration, the heat recovery ventilation unit <NUM> comprises two pre-heater sub-assemblies <NUM> to illustrate the positioning of the units. The pre-heater sub-assembly <NUM> along the second airstream pathway <NUM> can be installed/removed by simply sliding the pre-heater sub-assembly <NUM> into/out of the housing <NUM>.

However, the installation/removal of the pre-heater sub-assembly <NUM> along the first airstream pathway <NUM> requires modification of the pre-heater sub-assembly <NUM> to be installed/removed. This is described in greater detail in the description of <FIG>.

Part of an airstream swap unit <NUM> is visible but will be discussed in the figure description of <FIG>, <FIG>.

<FIG> illustrates cross-section B-B and C-C of <FIG>. The cross-section discloses the housings <NUM> defining a bypass channel <NUM> defining a bypass airstream pathway bypassing the polygonal heat exchanger <NUM>. The polygonal heat exchanger <NUM> form a side of the bypass channel <NUM> which makes the bypass channel <NUM> accessible when removing the polygonal heat exchanger <NUM> and this enables the distance between the backside <NUM> and front side <NUM> to be reduced.

The first filter <NUM> and optionally the pre-heater sub-assembly <NUM> are positioned upstream to the bypass channel <NUM> and the polygonal heat exchanger <NUM>.

<FIG> illustrates cross-section D-D of <FIG>. The cross-section discloses both the first ventilator <NUM> and the second ventilator <NUM>.

The airstream swap unit <NUM> has an exchanger section <NUM> facing the polygonal heat exchanger <NUM> and a bypass section <NUM> facing the bypass channel <NUM>. The actuator <NUM> is positioned at the bypass section <NUM> to avoid condensation on the actuator <NUM>. The actuator <NUM> controls whether the airstream swap unit <NUM> is at a heat recovery position <NUM>, where the bypass airstream pathway <NUM> is blocked, or at a bypass position <NUM>, where the first airstream pathway <NUM> is blocked.

<FIG> illustrates cross-section E-E of <FIG> and discloses a bottom of the housing <NUM> comprising a first condensation outlet <NUM> and second condensation outlet <NUM>. The figure shows the first outlet <NUM>" of the first outlet manifold <NUM> next to the first ventilator <NUM>, which would be positioned above the first outlet <NUM>", see <FIG>. The figure further shows the second outlet <NUM>" of the second outlet manifold <NUM> next to the second ventilator <NUM> which would be positioned above the first outlet <NUM>", see <FIG>.

<FIG> illustrates cross-section F-F of <FIG> showing the bypass channel <NUM> defined by the housing <NUM>. The first airstream pathway <NUM> is marked before and after the bypass channel <NUM> defining the bypass airstream pathway <NUM>. The airstream swap unit <NUM> controls whether the polygonal heat exchanger <NUM> is bypassed or not.

The marked box is discussed in greater detail in <FIG> as the shown pre-heater sub-assembly <NUM> cannot be installed through the first inlet <NUM> shown in <FIG>.

<FIG> illustrates an airstream swap unit <NUM>. The airstream swap unit <NUM> is adapted to be positioned downstream to the polygonal heat exchanger <NUM> and the bypass airstream pathway <NUM>. The airstream swap unit <NUM> is configurable between a heat recovery position <NUM>, where the bypass airstream pathway <NUM> is blocked, and a bypass position <NUM>, where the first airstream pathway <NUM> is blocked.

The airstream swap unit <NUM> comprises a stationary grate <NUM> and a slidable grate <NUM>. The grates <NUM>, <NUM> comprising a series of complementary apertures <NUM> at a bypass section <NUM> for facing the bypass channel <NUM> and at an exchanger section <NUM> for facing a side of the polygonal heat exchanger <NUM>. The apertures <NUM> are offset between the bypass section <NUM> and the exchanger section <NUM> to achieve the following effect wherein.

The airstream swap unit <NUM> comprises an actuator <NUM> adapted for displacing the slidable grate <NUM> between the heat recovery position <NUM> (<FIG>) and the bypass position <NUM> (<FIG>).

The actuator <NUM> is connected to the bypass section <NUM> as depending on the airstream along the first airstream pathway <NUM> condensation may be formed downstream to the polygonal heat exchanger <NUM> thus the condensation will not be formed on the actuator <NUM>.

<FIG> illustrates the airstream swap unit <NUM> of <FIG> positioned relative to the polygonal heat exchanger <NUM>.

The airstream swap unit <NUM> is positioned along a side of the polygonal heat exchanger <NUM>, this part of the airstream swap unit <NUM> is the exchanger section <NUM> and the remaining part is the bypass section <NUM> to face the bypass channel.

<FIG> discloses that the stationary grate <NUM> comprises between the exchanger section <NUM> and bypass section <NUM> a block part <NUM> arranged to prevent leak flow. The block part <NUM> extent substantially along a front side or a backside of the polygonal heat exchanger <NUM>, which further decreases the risk of leak flow.

<FIG> illustrates a pre-heater sub-assembly <NUM>. The pre-heater sub-assembly <NUM> is designed such that the pre-heater sub-assembly <NUM> can be in the chamber shown in <FIG> and marked box in <FIG>.

In this case, the first filter <NUM> and the polygonal heat exchanger <NUM> is removed from the heat recovery ventilation unit <NUM> before the pre-heater sub-assembly <NUM> is inserted into chamber.

<FIG> discloses that the pre-heater sub-assembly <NUM> comprises a heater element <NUM>, heater element holder and upper and lower flexible parts 19I,19II extending from opposite ends of the heater element holder.

The upper and lower flexible parts 19I,19II are adapted to be wedged between sides of a housing <NUM> as shown in <FIG>. The housing <NUM> may be adapted to engage ends of the upper and lower flexible parts 19I,19II.

The upper and lower flexible parts 19I,19II are flexible to achieve a spring force such that a biasing force is established between the upper and lower flexible parts 19I,19II thereby securing the pre-heater sub-assembly <NUM>.

The upper flexible part <NUM> comprises a bent defining a foot adapted to engage a slit formed in the housing.

Claim 1:
A heat recovery ventilation unit (<NUM>) comprising
- a polygonal heat exchanger (<NUM>) and a housing (<NUM>), wherein the polygonal heat exchanger (<NUM>) and the housing (<NUM>) define
- a first inlet (<NUM>) and a first outlet (<NUM>) defining a first airstream pathway (<NUM>) from the first inlet (<NUM>) to the first outlet (<NUM>) through the polygonal heat exchanger (<NUM>);
- a second inlet (<NUM>) and a second outlet (<NUM>) defining a second airstream pathway (<NUM>) from the second inlet (<NUM>) to the second outlet (<NUM>) through the polygonal heat exchanger (<NUM>);
- the housing (<NUM>) further comprises
- a bypass channel (<NUM>) arranged to bypass the polygonal heat exchanger (<NUM>) along the first airstream pathway (<NUM>), thereby defining a bypass airstream pathway (<NUM>),
- an airstream swap unit (<NUM>) downstream to the polygonal heat exchanger (<NUM>) and the bypass airstream pathway (<NUM>), the airstream swap unit (<NUM>) being configurable between a heat recovery position (<NUM>), where the bypass airstream pathway (<NUM>) is blocked, and a bypass position (<NUM>), where the first airstream pathway (<NUM>) is blocked.
characterised in that
the housing (<NUM>) is substantially formed by insulation material, and
the airstream swap unit (<NUM>) comprises a stationary grate (<NUM>) and a slidable grate (<NUM>), the grates (<NUM>, <NUM>) comprising a series of complementary apertures (<NUM>) at a bypass section (<NUM>) facing the bypass channel (<NUM>) and at an exchanger section (<NUM>) facing a side of the polygonal heat exchanger (<NUM>), wherein the apertures (<NUM>) are offset between the bypass section (<NUM>) and the exchanger section (<NUM>), wherein
- at the heat recovery position (<NUM>), the slidable grate (<NUM>) is positioned such that the apertures (<NUM>) at the heat exchanger section (<NUM>) overlap and the apertures (<NUM>) at the bypass section (<NUM>) are blocked, and
- at the bypass position (<NUM>), the slidable grate (<NUM>) is positioned such that the apertures (<NUM>) at the bypass section overlap (<NUM>) and the apertures (<NUM>) at the exchanger section (<NUM>) are blocked.