Heat Recovery Air Handling Unit

Abstract

An exemplary heat recovery air handling unit includes an inner module, an outer module, a central module with a plate recuperator, fans, an inlet chamber of the exhaust duct, an outlet chamber of the exhaust duct, an inlet chamber of the intake duct, an outlet chamber of the intake duct, and a partition between the inlet and outlet chambers of the exhaust and intake ducts, respectively. A recuperator of counterflow or crossflow type may be used as the plate recuperator, and the fans create opposing airflows. The heat recovery air handling unit also includes a condensate removal system.

Description

FIELD OF THE INVENTION

[0001] The invention generally relates to ventilation equipment, and more particularly to heat recovery air handling units.BACKGROUND

[0002] The state of the art discloses various technical solutions, shapes, and constructions designed for natural ventilation of both residential and commercial buildings.

[0003] The drive to find optimal ventilation system solutions is motivated by the aim to design buildings in a way that ensures maximum energy efficiency in the building. However, increasing the energy efficiency coefficient of a building proportionally reduces the natural self-regulation of the indoor climate. In other words, in such buildings, due to the use of central heating, the operation of numerous household appliances, and other modern technological factors, significant indoor air drying occurs. This, in turn, creates favourable conditions for the development of allergic diseases and respiratory complications or illnesses.

[0004] In spring and summer, energy-efficient buildings poorly remove excess humidity, hindering natural air circulation inside the premises and thus creating favourable conditions for the growth of mould and harmful microorganisms.

[0005] The above statements have long been known. Therefore, in many developed countries, medical institutions recommend frequent ventilation of premises. Most countries implement regulations governing air exchange systems.

[0006] Ventilation is mainly achieved by opening windows, thereby allowing natural air circulation inside the premises. However, ventilation solely through window opening causes many inconveniences. In particular, during winter, an open window significantly cools the room due to its surface area, while in summer it causes overheating. As a result, this leads to considerable energy consumption to maintain acceptable and comfortable working and living conditions. Consequently, continuous efforts are being made to develop and enhance ventilation systems.

[0007] A known heat recovery air handling unit is described in Ukrainian utility model UA 146223, dated Jan. 27, 2021, which describes a recuperator with air ducts, a fan, and a heat exchanger, interconnected and mounted in the wall of a room between its external and internal surfaces. Two straight-through concentric cylinders are installed in the opening between the external and internal surfaces of the room, and between them, on the outer surface of the inner cylinder, an Ω-shaped (in cross-section) corrugated heat exchanger is fixed. Additionally, on the inner surface of the cylinder, opposite to each other, external and internal fans are installed. The unit openings are equipped with corresponding external and internal covers, where the internal cover is provided with a supply air grille and an internal air outlet slot with an air diffuser. The external cover is additionally equipped with a condensate drain opening extending beyond the plane of the external wall surface, an air intake grille, and a corresponding grille for the exhaust of internal air.

[0008] The drawbacks of this heat recovery air handling unit are a low degree of air heat exchange efficiency. When air passes along the heat exchange surface of the corrugated heat exchanger, the presence of cut-outs in the troughs of the heat exchanger reduces the heat exchange area. The low level of air exchange performance arises because the airflows in the unit are unbalanced.

[0009] Additionally, a drawback is the lack of resistance to wind loads. Since the outer module is of an open type, it does not provide wind protection for the exhaust duct and leads to the risk of the unit freezing at sub-zero temperatures.

[0010] Since it is structurally impossible to install full-fledged heaters and filtering elements, and the power supply unit is located in the room module, as a result, additional heating of the recuperator is not provided. The design of the heat exchanger causes excessive condensation and leads to possible freezing of the unit.

[0011] Another known heat recovery air handling unit is described in EP4417886A1, dated Aug. 21, 2024, which is designed for installation into an external wall of a building. That unit has an inner module and an adjacent heat exchange module, which consists of a cylindrical corrugated heat exchanger with a multitude of heat exchange air channels arranged along the symmetry axis of the heat exchanger. These air channels have identical cross-sections and are adjacent to each other, forming a continuous corrugated volume of heat exchange segments. The first separator and the second separator are provided for separating and directing the exhaust and supply airflows in opposite directions within the heat exchange air ducts. The first and second separators are attached to the heat exchanger on both of its end surfaces and mounted along the symmetry axis of this heat exchanger. The first fan and the second fan, whose housings are adjacent to the first and second separators respectively, are installed at the ends of the separators facing away from the heat exchanger. The axis of one fan is arranged parallel to, but not coaxial with, the axis of the other fan.

[0012] The drawbacks of this heat recovery air handling unit include a low level of air heat exchange efficiency, low air exchange performance, a heat exchanger design that causes excessive condensation, and insufficiently effective condensate removal from the unit, which may lead to the unit freezing during cold seasons.

[0013] A known heat recovery air handling unit is described as set forth at https: / / www.dimplex.eu / de-de / decentralised-domestic-ventilation-unit-d1-50-wa2 #372710, which describes an inner module, an outer module, and a central module. The central module contains a recuperator and fans.

[0014] The drawbacks of this heat recovery air handling unit are as follows:

[0015] the central module has a complex design, making maintenance and operation of the unit difficult: the fans are not integrated into a fan module;

[0016] there is no condensate removal system, such as a condensate collection tank, a pump for removing condensate outside the unit, or a drainage channel for condensate discharge. This leads to excessive accumulation of condensate and potential freezing in countries with cold climates;

[0017] there is no heating element in the inlet chamber of the intake duct for preheating the air, which is necessary to prevent condensation;

[0018] there is no heating element in the outlet chamber of the intake duct for reheating the air, which is used to ensure a comfortable intake air temperature in countries with cold climates;

[0019] there are no filters, which results in polluted air and insects entering the unit and the premises.SUMMARY

[0020] The objective of the present invention is to create a heat recovery air handling unit, in which:

[0021] a high level of air heat exchange efficiency is achieved through the placement of a counterflow or crossflow plate recuperator in the central module;

[0022] a high level of air exchange performance is ensured due to the structural arrangement of the fans;

[0023] airflow mixing is prevented by means of partitions placed in the central module between the inlet and outlet chambers of the exhaust and intake air ducts;

[0024] maximum efficient heat transfer from the heaters is achieved through the full integration of heaters in both the inlet chamber and outlet chamber of the intake air duct;

[0025] excessive accumulation of condensate and subsequent freezing of the unit in cold climates is prevented due to a condensate removal system, namely: a condensate collection tank and a channel for discharging condensate outside the unit, or a channel for discharging condensate outside the unit, or a pump for discharging condensate outside the unit, or a pump and channel for discharging condensate outside the unit, or an evaporator;

[0026] ingress of polluted air and insects into the unit and indoor space is prevented due to the presence of filters.

[0027] The stated objective is achieved as follows. The heat recovery air handling unit includes an inner module, an outer module, a central module with a plate recuperator, fans, an inlet chamber of the exhaust air duct, an outlet chamber of the exhaust air duct, an inlet chamber of the intake air duct, an outlet chamber of the intake air duct, and a partition between the inlet and outlet chambers of the exhaust and intake air ducts, respectively. A counterflow or crossflow type recuperator is used as the plate recuperator, and the fans generate opposing airflows. One fan is positioned in the inlet chamber of the intake air duct, and the other fan is positioned in the outlet chamber of the exhaust air duct; or one fan is positioned in the inlet chamber of the exhaust air duct, and the other in the outlet chamber of the intake air duct; or one fan is positioned in the inlet chamber of the exhaust air duct, and the other in the inlet chamber of the intake air duct; or one fan is positioned in the outlet chamber of the intake air duct, and the other in the outlet chamber of the exhaust air duct; and includes a condensate removal system.

[0028] In one of the embodiments that solves the stated problem, the fans in the heat recovery air handling unit can be combined into a fan module.

[0029] In one of the embodiments that solves the stated problem, the heat recovery air handling unit features an inlet chamber of the intake duct that contains a heater for pre-heating the air.

[0030] In one of the embodiments that solves the stated problem, the heat recovery air handling unit features an outlet chamber of the intake duct that contains a heater for post-heating the air.

[0031] In one of the embodiments that solves the stated problem, the fans in the heat recovery air handling unit have a mechanical damper and / or a gravity valve.

[0032] In one of the embodiments that solves the stated problem, the housing of the central module in the heat recovery air handling unit has an external thermal insulation shell.

[0033] In one of the embodiments that solves the stated problem, the heat recovery air handling unit has a condensate removal system that includes a condensate collection tank and a channel for discharging condensate outside the unit.

[0034] In one of the embodiments that solves the stated problem, the heat recovery air handling unit has a condensate removal system that includes a channel for discharging condensate outside the unit.

[0035] In one of the embodiments that solves the stated problem, the heat recovery air handling unit has a condensate removal system that includes a pump for discharging condensate outside the unit.

[0036] In one of the embodiments that solves the stated problem, the heat recovery air handling unit, the condensate removal system comprises a pump and a drainage channel for discharging condensate outside the unit.

[0037] In one of the embodiments that solves the stated problem, the heat recovery air handling unit has a condensate removal system that includes a condensate collection tank with an ultrasonic evaporator.

[0038] In one of the embodiments that solves the stated problem, the heat recovery air handling unit has filters placed in the inlet chamber of the exhaust duct and the inlet chamber of the intake duct.

[0039] In one of the embodiments that solves the stated problem, the inner module of the heat recovery air handling unit has an inner damper, and / or inner intake and inner exhaust grilles, while the outer module has outer intake and outer exhaust grilles.

[0040] In one of the embodiments that solves the stated problem, the outer module of the heat recovery air handling unit has outer dampers, and / or outer intake and outer exhaust grilles, while the inner module has inner intake and inner exhaust grilles.

[0041] In one of the embodiments that solves the stated problem, one fan and / or the other fan in the heat recovery air handling unit are positioned at an angle to a conditional axis of symmetry of the unit.

[0042] The heat recovery air handling unit described herein differs from the documents described above in at least the following aspects:

[0043] a counterflow or crossflow plate recuperator in the central module, resulting in a high degree of air heat exchange efficiency for the unit;

[0044] two fans in the central module, positioned either in the inlet chamber of the intake duct and the outlet chamber of the exhaust duct, or in the inlet chamber of the exhaust duct and the outlet chamber of the intake duct, or in the inlet chamber of the exhaust duct and the inlet chamber of the intake duct, or in the outlet chamber of the intake duct and the outlet chamber of the exhaust duct, contributing to a high degree of air exchange performance.

[0045] optimal placement of heaters in the inlet chamber of the intake duct and the outlet chamber of the intake duct, ensuring maximum efficient heat transfer from the heaters.

[0046] a condensate removal system, which prevents excessive condensate accumulation and subsequent icing of the unit in cold climates.

[0047] filters, which prevent contaminated air and insects from entering the unit and the premises.

[0048] The heat recovery air handling unit describes herein solves the stated problem, and ensures a high degree of heat exchange efficiency and a high degree of air exchange performance.BRIEF DESCRIPTION OF THE DRAWINGS

[0049] FIG. 1 is a perspective view of a heat recovery air handling unit.

[0050] FIG. 2 is a schematic representation of the heat recovery air handling unit of FIG. 1, with parallel arrangement of fans in an inlet chamber of an intake duct and an outlet chamber of an exhaust duct;

[0051] FIG. 3 is a schematic representation of the heat recovery air handling unit of FIG. 1, with parallel arrangement of fans in an inlet chamber of an exhaust duct and an outlet chamber of an intake duct;

[0052] FIG. 4 is a schematic representation of the heat recovery air handling unit of FIG. 1, with fans located in an inlet chamber of an exhaust duct and an inlet chamber of an intake duct;

[0053] FIG. 5 is a schematic representation of the heat recovery air handling unit of FIG. 1, with fans located in an outlet chamber of an intake duct and an outlet chamber of an exhaust duct;

[0054] FIG. 6 is a schematic representation of warm and cold air movement within the heat recovery air handling unit of FIG. 1.

[0055] The use of the same reference symbols in different figures indicates similar or identical items.

[0056] In FIGS. 1-6, the following positions are marked:

[0057] 1—heat recovery air handling unit

[0058] 2—inner module

[0059] 3—central module

[0060] 4—outer module

[0061] 5—plate heat exchanger

[0062] 6—inlet chamber of the exhaust duct

[0063] 7—outlet chamber of the exhaust duct

[0064] 8—inlet chamber of the intake duct

[0065] 9—outlet chamber of the intake duct

[0066] 10—partition

[0067] 11, 26—fans

[0068] 12—mechanical damper

[0069] 13—gravity valve

[0070] 14—pre-heating element

[0071] 15—post-heating element

[0072] 16—filter

[0073] 17—external thermal insulation shell

[0074] 18—condensate drainage channel

[0075] 19—condensate collection tank

[0076] 20—fan module

[0077] 21—inner intake grille

[0078] 22—inner exhaust grille

[0079] 23—inner damper

[0080] 24—outer intake grille

[0081] 25—outer exhaust grille

[0082] 27—ultrasonic evaporator

[0083] 28—condensate drainage pump

[0084] 29—outer damper.DETAILED DESCRIPTION

[0085] Referring to FIG. 1, a heat recovery air handling unit (1) includes an inner module (2), a central module (3), and an outer module (4). The central module (3) is surrounded by an external thermal insulation shell (17), which is used to reduce heat transfer to the surrounding structures (wall) and improves the unit's noise characteristics.

[0086] Referring also to FIGS. 2-6, in the heat recovery air handling unit (1), two fans (11), (26) may be combined into a fan module (20). The fans (11) (26) of the heat recovery air handling unit (1) are equipped with a mechanical damper (12) and / or a gravity valve (13).

[0087] The heat recovery air handling unit (1) may include a condensate removal system. In some embodiments, the condensate removal system may include a condensate collection tank (19) and a drainage channel (18) for discharging condensate outside the unit (1). In some embodiments, the condensate removal system may include a drainage channel (18) for discharging condensate outside the unit (1). In some embodiments, the condensate removal system may include a pump (28) for discharging condensate outside the unit (1). In some embodiments, the condensate removal system may include a combination of a pump (28) and a drainage channel (18) for discharging condensate outside the unit (1). In some embodiments, the condensate removal system may include a condensate collection tank (19) with an ultrasonic evaporator (27).

[0088] The inlet chamber of the intake duct (8) may contain a heater (14) for pre-heating the air. This heater (14) is used for pre-heating the air to combat condensation. The outlet chamber of the intake duct (9) contains a heater (15) for post-heating the air. The post-heating element (15) is used to ensure a comfortable intake air temperature in countries with cold climates.

[0089] The central module (3) may contain filters (16) in the inlet chamber of the exhaust duct (6) and the inlet chamber of the intake duct (8). These filters (16) are used to protect the plate recuperator of counterflow or crossflow type (5) and the radial fans (11) from contaminated air and insects entering them and the premises. The filters (16) can be treated with an antibacterial agent.

[0090] The inner module (2) has an inner damper (23), and / or inner intake (21) and inner exhaust (22) grilles, while the outer module (4) has outer intake (24) and outer exhaust (25) grilles.

[0091] The outer module (4) has outer dampers (29), and / or outer intake (24) and outer exhaust (25) grilles, while the inner module (2) has inner intake (21) and inner exhaust (22) grilles.

[0092] By plate recuperator (5) is meant a heat exchanger pack that includes thin profiled plates (not shown) arranged parallel to each other, forming a solid pack with separated hermetic channels for the movement of two air streams in opposite directions.

[0093] Referring also to FIGS. 2-6, the movement of warm air (dashed line) and cold air (solid line) through the heat recovery air handling unit (1) is schematically shown.

[0094] The heat recovery air handling unit (1) operates as follows. After the heat recovery air handling unit (1) is switched on, the exhaust and intake fans (11), (26) are activated, initiating air exchange within the unit. Warm, used air from the room enters the inner module (2), flows through the inlet chamber of the exhaust duct (6), and enters the plate recuperator (5), where it heats the latter. Upon exiting the plate recuperator (5), the air enters the outlet chamber of the exhaust duct (7), where the exhaust fan (26) is located. It then passes through the outer module (4) and is discharged outside through the exhaust grille (21).

[0095] Simultaneously with the movement of warm air, cold fresh air is supplied. Cold air from outside enters the outer module (4) through the supply grille (21), passes through the inlet chamber of the intake duct (8), where the intake fan (11) is located, and enters the plate heat exchanger (5). The cold air entering the plate recuperator (5) is heated in the process.

[0096] As it exits the plate recuperator (5), the fresh but preheated air passes through the outlet chamber of the intake duct (9), then moves through the inner module (2) and enters the premises.

[0097] A partition (10) is placed between the inlet chamber of the intake duct (8) and the outlet chamber of the exhaust duct (7), as well as between the inlet chamber of the exhaust duct (6) and the outlet chamber of the intake duct (9), to prevent the mixing of airflows. As a result of the operation of the heat recovery air handling unit (1), heat exchange occurs between the warm and cold air, while the airflows do not mix.

[0098] Referring to FIG. 2, the heat recovery air handling unit (1) is schematically shown with the fans (11) (26) arranged in parallel, located in the inlet chamber of the intake duct (8) and the outlet chamber of the exhaust duct (7), respectively. FIGS. 3-5 show other configurations of fan (11), (26) placement, with the heat exchange process operating according to the same principle.

[0099] The operation of the heat recovery air handling unit (1) may be carried out using a keypad on the side panel of the unit, via an infrared remote control, and / or through a mobile application over a wireless Wi-Fi network.

[0100] The heat recovery air handling unit (1) may be fabricated in such a way that the inner module (2) and the central module (4) can be easily connected to and disconnected from an associated ventilation duct, which simplifies maintenance during repair or preventive servicing.

[0101] The examples provided serve solely for descriptive purposes, and do not limit the possible implementations of the heat recovery air handling unit (1).

Claims

1. A heat recovery air handling unit (1), comprising:an inner module (2),an outer module (4),a central module (3) between said inner module (2) and said outer module (4) with a plate recuperator (5), fans (11) (26), an inlet chamber of the exhaust duct (6), an outlet chamber of the exhaust duct (7), an inlet chamber of the intake duct (8), an outlet chamber of the intake duct (9), and a partition (10) between the inlet and outlet chambers of the exhaust and intake ducts, respectively;wherein said plate recuperator (5) is a counterflow or crossflow type recuperator, and said fans (11), (26) form opposing airflows by an configuration selected from the group consisting of:said fan (11) is located in said inlet chamber of said intake duct (8), and said fan (26) is located in said outlet chamber of said exhaust duct (7),said fan (26) is located in the inlet chamber of the exhaust duct (6), and said fan (11) is located in said outlet chamber of the intake duct (9),said fan (26) is located in the inlet chamber of the exhaust duct (6), and said fan (11) is located in said inlet chamber of the intake duct (8), andsaid fan (11) is located in the outlet chamber of the intake duct (9), and said fan (26) is located in said outlet chamber of the exhaust duct (7); anda condensate removal system associated with said central module (3).

2. The heat recovery air handling unit according to claim 1, wherein said fans (11), (26) are combined into a fan module (20).

3. The heat recovery air handling unit according to claim 1, wherein said inlet chamber of the intake duct (8) further comprises a heater (14) for pre-heating the air.

4. The heat recovery air handling unit according to claim 1, wherein said outlet chamber of the intake duct (9) further comprises a heater (15) for post-heating the air.

5. The heat recovery air handling unit according to claim 1, wherein said fans (11), (26) further comprise at least one of a mechanical damper (12) and a gravity valve (13).

6. The heat recovery air handling unit according to claim 1, wherein a housing of said central module (3) further comprises an external thermal insulation shell (17).

7. The heat recovery air handling unit according to claim 1, wherein said condensate removal system further comprises:a tank (19) for collecting condensate, anda channel (18) for removing condensate outside the heat recovery air handling unit (1).

8. The heat recovery air handling unit according to claim 1, wherein said condensate removal system further comprises a channel (18) for removing condensate outside the heat recovery air handling unit (1).

9. The heat recovery air handling unit according to claim 1, wherein said condensate removal system further comprises a pump (28) for removing condensate outside the heat recovery air handling unit (1).

10. The heat recovery air handling unit according to claim 1, wherein said condensate removal system further comprises a pump (28) and a channel (18) for removing condensate outside the heat recovery air handling unit (1).

11. The heat recovery air handling unit according to claim 1, wherein said condensate removal system further comprises a container (19) for collecting condensate with an ultrasonic evaporator (27).

12. The heat recovery air handling unit according to claim 1, further comprising filters (16) positioned in said inlet chamber of said exhaust duct (6) and in said inlet chamber of said intake duct (8).

13. The heat recovery air handling unit according to claim 1, whereinsaid inner module (2) has an inner damper (23), and / or inner intake (21) and inner exhaust (22) grilles; andsaid outer module (4) has outer intake (24) and outer exhaust (25) grilles.

14. The heat recovery air handling unit according to claim 1, whereinsaid outer module (4) has outer dampers (29), and / or outer intake (24) and outer exhaust (25) grilles; andsaid inner module (2) has inner intake (21) and inner exhaust (22) grilles.

15. The heat recovery air handling unit according to claim 1, wherein at least one of said fans (11), (26) is positioned at an angle to a conditional axis of symmetry of the heat recovery air handling unit (1).

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