WO2025147469A1

WO2025147469A1 - Modular unit for kiln drying systems

Info

Publication number: WO2025147469A1
Application number: PCT/US2024/062412
Authority: WO
Inventors: James Parker
Original assignee: Green Mountain Mechanical Design Inc
Current assignee: Green Mountain Mechanical Design Inc
Priority date: 2024-01-03
Filing date: 2024-12-31
Publication date: 2025-07-10
Anticipated expiration: 2026-07-03

Abstract

A modular unit for attaching to a container for holding materials to be dried converts the container into a drying kiln. One side of the modular unit is designed to be attached to the container over an opening in the container such that the side encompasses the opening. The container can be any container suitable for holding materials during the drying process, such as a shipping container or a shed. The modular unit may include a housing on all sides except for the portion of the unit designed to interface with the container, and in particular to be attached over an opening in the container. Accessible on the outside of the housing are electrical and communication connections as well as a display /control panel. The display/control panel may include a user interface with readouts for air temperature, humidity, fan status, heater status, and power status.

Description

MODULAR UNIT FOR KILN DRYING SYSTEMS

RELATED APPLICATION DATA

[0001] This application claims the benefit of priority of U.S. Provisional Patent Application Serial No. 63/617,153, filed January 3, 2024, and titled “Modular Unit For Kiln Drying Systems,” which is incorporated by reference herein in its entirety.

FIELD OF THE DISCLOSURE

[0002] The present disclosure generally relates to the field of kiln drying, and more specifically to a modular unit for kiln drying systems.

BACKGROUND

[0003] There are differing ways to dry materials, including steaming, dehumidification, air drying, and with kilns. Most of these methods take significant time, effort, and experience to manage so as to produce properly dried materials in a reasonable amount of time.

[0004] Drying of organic materials, such as lumber, are often carried out in kilns, which may be containers or other structures that house the material to be dried. Various methods may be used to control the drying process, including applying heat, applying a vacuum to reduce pressure, increasing air circulation, and/or using a dehumidifier. Kilns may be large, and for any lumber drying kiln the drying process requires monitoring and controlling the drying parameters to ensure the drying process occurs at an appropriate pace for the type (e.g., species) and condition (e.g., size of pieces) of wood being dried. Because of these requirements, kilns for drying lumber are often expensive and/or difficult to operate. Therefore, there is a need for a relatively inexpensive kiln system for easily and reliably drying lumber appropriately.

SUMMARY OF THE DISCLOSURE

[0005] A system for drying wood includes a housing having a fan, a heating device, and a baffle on a rear side of the housing forming a first side aperture and a second side aperture, and a container with an opening, wherein the housing is configured to attach to the container such that the rear side encompasses the opening and wherein the container is configured to accommodate stacked lumber such that a first side air gap, and second side air gap are formed between the stacked lumber and side walls of the container. When the housing is attached to the container and the stacked lumber is in the container, the first side aperture is in communication with the first side air gap, the second side aperture is in communication with the second side air gap, and the fan is positioned and configured to generate lateral airflow circulation from the first side aperture through the first side air gap, the second side air gap and the second side aperture.

[0006] A modular unit for kiln drying systems includes a housing having a housing wall and a top, a bottom, a first side, a second side, a front, and a rear side, wherein the rear side is configured to be attached around an opening in a wall of a container such that the opening is encompassed by the rear side; a reversible air circulation device within the housing; a baffle disposed between the first side and the second side thereby forming a first side chamber and a second side chamber; and a divider configured to prevent airflow through the divider and to cover a portion of the rear side. The divider includes a first side opening and a second side opening, wherein the first side opening is configured to allow, when the unit is attached to the container, fluid communication between the first side chamber and the container and the second side opening configured to allow, when the unit is attached to the container, fluid communication between the second side chamber and the container. A first vent passageway run from the rear side to a first area of the housing wall not on the rear side, wherein the first vent passageway includes a first container-facing port at the rear side and an exterior port at the first area of the housing wall such that the first vent passageway is configured to allow airflow, when the unit is attached to the container, between the container and ambient air while bypassing the first side chamber. A second vent passageway runs from the rear side to a second area of the housing wall not on the rear side, wherein the second vent passageway includes a second container-facing port at the rear side and an exterior port at the second area of the housing wall such that the second vent passageway is configured to allow airflow, when the unit is attached to the container, between the container and ambient air while bypassing the second side chamber. A heating system is configured to heat air in the housing.

[0007] Additionally or alternatively, the air circulation device is positioned to direct airflow towards the first side when directing air in a first direction and towards the second side when directing air in a second direction.

[0008] Additionally or alternatively, the baffle extends from the divider to the front and from the top to the bottom and is configured to prevent airflow between the first side chamber and the second side chamber except via an aperture encompassing the circulation device. [0009] Additionally or alternatively, the first vent passageway runs only through the first side chamber and the second vent passageway runs only through the second side chamber.

[0010] Additionally or alternatively, the first area of the housing wall is on the front and the second area of the housing wall is on the front.

[0011] Additionally or alternatively, the divider extends from the top to the bottom, extends from the baffle toward the first side, and extends from the baffle toward the second side.

[0012] Additionally or alternatively, the first side opening extends from the top to the bottom and wherein the second side opening extends from the top to the bottom.

[0013] Additionally or alternatively, the first container-facing port is within the first side opening and the second container-facing port is within the second side opening.

[0014] Additionally or alternatively, a monitor and a control panel are attached to the housing and accessible from outside the unit.

[0015] Additionally or alternatively, the first side opening is covered by a grille and the second side opening is covered by a grille.

[0016] Additionally or alternatively, the monitor and control panel is electrically connected to the air circulation device and in communication with a temperature sensor and a humidity sensor.

[0017] Additionally or alternatively, the temperature sensor and the humidity sensor are within the housing.

[0018] Additionally or alternatively, the heating system includes one or more electrical resistance elements.

[0019] Additionally or alternatively, the heating system has a capacity of 6 KW.

[0020] Additionally or alternatively, the air circulation device includes a 2 HP motor.

[0021] Additionally or alternatively, a volume of the modular unit is less than 5000 liters.

[0022] Additionally or alternatively, the first vent passageway is passive and the second vent passageway is passive. [0023] Additionally or alternatively, a dehumidifier is included in the housing.

[0024] Additionally or alternatively, each of the first vent passageway and the second vent passageway includes a closing mechanism configured to move from an open state in which the respective vent passageway is substantially open to a closed state in which the respective vent passageway is substantially closed.

[0025] Additionally or alternatively, a first plate is in the first side chamber, the first plate extending from a top to a bottom of the first side chamber and angled between the front and the first side and a second plate is in the second side chamber, the second plate extending from a top to a bottom of the second side chamber and angled between the front and the second side.

[0026] Additionally or alternatively, the rear side includes a flange for attaching the unit to the container.

[0027] A system for drying wood includes a modular unit including an air circulation device, a heater, and a divider forming a first side chamber and a second side chamber, the modular unit having a front, a rear side and a baffle covering a portion of the rear side. A container with an opening over which the modular unit is configured to be attached such that the rear side encompasses the opening. When the modular unit is attached to the container, a first side opening in the rear side allows fluid communication between the first side chamber and the container and a second side opening in the rear side allows fluid communication between the second side chamber and the container, a first vent passageway runs from the rear side to a first area of a wall of the modular unit not facing the container, wherein the first vent passageway includes a first containerfacing port at the rear side and an exterior port at the first area of the wall such that the first vent passageway is configured to allow airflow between the container and ambient air while bypassing the first side chamber, and a second vent passageway runs from the rear side to a second area of the wall not facing the container, wherein the second vent passageway includes a second containerfacing port at the rear side and an exterior port at the second area of the wall such that the second vent passageway is configured to allow airflow between the container and ambient air while bypassing the second side chamber. The air circulation device is positioned and configured to direct air such that air flows from the first side chamber through the first side opening, into the container and through the second side opening into the second side chamber. BRIEF DESCRIPTION OF THE DRAWINGS

[0028] For the purpose of illustrating the disclosure, the drawings show aspects of one or more embodiments of the disclosure. However, it should be understood that the present disclosure is not limited to the precise arrangements and instrumentalities shown in the drawings, wherein:

FIG. 1 is a perspective front view of a modular kiln drying unit in accordance with an embodiment of the present disclosure;

FIG. 2 is a perspective rear view of the modular kiln drying unit of FIG. 1;

FIG. 3 is a front view of the modular kiln drying unit of FIG. 1;

FIG. 4 is a perspective view of a modular kiln drying unit attached to a container and supported on the front side;

FIG. 5 is a sectional side view of a modular kiln drying unit attached to a container in accordance with an embodiment of the present disclosure;

FIG. 6 is a detail side view of an attachment point for the modular kiln drying unit to the container;

FIG. 7 is a detail side view of another attachment point for the modular kiln drying unit to the container;

FIG. 8 is a sectional front view of a modular unit attached to a container;

FIG. 9 is a detail rear view of a top attachment point for the modular kiln drying unit to the container;

FIGS. 10A-10D depict a container and a modular kiln drying unit attached to the container;

FIG. 11 A is a rear perspective view of a container with lumber positioned for drying when a modular kiln drying unit is attached;

FIG. 1 IB is a side cross view of a container with lumber positioned for drying when a modular kiln drying unit is attached;

FIGS. 12-13 depict a display/user interface for a modular kiln drying unit;

FIG. 14 is a schematic illustration of airflow through a modular drying unit and container with lumber;

FIG. 15 is a perspective front view of a modular kiln drying unit in accordance with another embodiment of the present disclosure; FIG. 16 is a rear perspective view of the unit of FIG. 15;

FIG. 17 is a rear view of the unit of FIG. 15 with plate and screens removed;

FIG. 18 is another rear view of the unit of FIG. 1 with plate and screens removed;

FIG. 19 is a top view of the unit of FIG. 15 with housing top removed;

FIG. 20 is a front view of the unit of FIG. 15 with access panels removed; and

FIGS. 21A-21B are detail views of a damper assembly.

DETAILED DESCRIPTION

[0029] A modular unit is provided for attaching to a container for holding lumber (or other material to be dried) to convert the container into a drying kiln for the lumber. One side of the modular unit is designed to be attached to the container over an opening in the container, preferably such that the side encompasses the opening. The container can be any container suitable for holding lumber during the drying process, such as a shipping container or a shed. The modular unit may include a housing, which may be any suitable material such as metal or high density polyethylene, on all sides except for the portion of the unit designed to interface with the container, and in particular to be attached over an opening in the container. Accessible on the outside of the housing are electrical and communication connections as well as a di splay /control panel. The display/control panel may include a user interface with readouts for air temperature, humidity, fan status, heater status, wood type selected, and power status. In addition, graphs may be displayed with temperature and relative humidity shown over time.

[0030] The modular unit includes a fan, which is preferably variable speed and reversible, sized and positioned to circulate air through the modular unit and the container to which it is attached. In a preferred embodiment, the fan is configured to generate air flow toward a first side of the modular unit (i.e., perpendicular to the direction toward the opening in the container) in a forward mode and toward an opposite, second side of the modular unit when in a reverse mode. A barrier may be included between the interior of the unit and the opening of the container that prevents airflow between the unit and the container except through one or more openings in the barrier. In an embodiment, the barrier runs from the top to the bottom of the unit and from the middle of the opening toward each side. In this way, an airflow gap is present along each side of the unit, each of which may also include a grille sized to prevent particulates of a selected size from passing to and from the container. [0031] Running from each airflow gap to outside the unit, and preferably to the front of the unit are at least a pair of vent passageways, which are preferably passive air conduits that encompass a portion of the volume within the unit between the opening and the front of the unit. One or more heating devices may also be included within the unit, such as electrical resistance heating elements or other suitable heating means. A dehumidifier may also be included in or be attached to the unit.

[0032] The unit is attached to the container over the opening in the container by any suitable means (e.g., structural screws) such that the opening is completely encompassed by the rear side of the unit and such that the interface between the unit and the container is relatively airtight.

[0033] In operation, when the unit is attached over the opening of the container, the fan blows air toward the side wall of the unit. The air may be heated within the unit when the heating elements are on, which may be controlled through the display/control panel either as part of a drying program or by user input. Because the vent conduits run through the unit and because of the placement of the barrier, the moving air is forced through the air gap and thus into the container, where, with the container having stacks of wood for drying, the air travels down a side of the container, through the wood, and back toward the unit on the opposite side of the container (as shown schematically in FIG. 14 with arrows illustrating the direction of airflow). This lateral airflow circulation, when reversed regularly, allows for efficient drying of lumber with fewer components and a largely unmodified container. The heated air, as it passes over the wood and through the container, picks up moisture and cools, and, due to the continuing operation of the fan, is forced back into the unit through the airgap on the other side of the unit, where it is pulled in by the fan and reheated by the heater and continues the circulation pattern. At the same time, the circulating air will tend to draw outside air in through the vent passageway on one side of the unit (the side toward which the airflow of the fan is directed) to the container and push air out from the container of the vent passageway on the other side of the unit (the side facing away from the direction of airflow of the fan) into ambient air. The direction of the airflow, and the direction of air passing into and out of the vent passageways, are reversed when the fan is reversed. Preferably, the direction of the fan is switched regularly during a drying session, such as every few hours during a four day drying period, in order to promote even drying of the wood.

[0034] An exemplary modular unit 100 is shown FIGS. 1-3, and includes a housing 104, a front

108, a rear 112, a first side 116a, and a second side 116b. Exterior vent ports 120 (e.g., 120a, 120b) of vent passageways 124 (e.g., 124a, 124b) may be located on front side 108. A display/control panel maybe included on housing 104 and may include electrical and communication connections.

[0035] As can be seen in FIG. 2, for example, container-side vent ports 132 (e.g., 132a, 132b) are positioned to interface with air inside a container. In this way, vent passageways 124, which may be made of plastic or metal tubes, for example, provide fluid communication between air inside the container and ambient air outside the unit and the container while bypassing air within the unit 100.

[0036] Rear 112 includes a divider 136 (shown as transparent in FIG. 2 for clarity) that prevents airflow between the unit 100 and the container it is attached to except through openings, such as a first side opening 140a and a second side opening 140b, which may preferably be covered by a grille or other material that allows airflow but prevents particulates from passing. One or more air circulation devices, such as air circulation device 144, are included within housing 104. In a preferred embodiment, air circulation device 144 is reversible and is positioned to direct air toward first side 116a or second side 116b. In a preferred embodiment, a baffle 148 divides unit 100 into a first side chamber and a second side chamber and includes an opening within which air circulation device 144 is disposed. (It will be understood that other arrangements may be used, such as a solid baffle with air circulation devices on either side.) Air within unit 100 may be heated, such as with heating elements (e.g., heating element 156).

[0037] In a preferred embodiment, the area of the container-facing vent port will cover about 10% of the area of the opening.

[0038] Exterior vent ports 120 may include a vent control mechanism that allows the vents to be substantially open or closed (or partially open) and can be controlled during the drying process to limit or promote intake or exhaust from either port according to the stage of drying, sensed conditions, and current direction of air circulation in the unit/container. In general, the vents are controlled to maintain a certain relative humidity of air in the unit/container as determined by sensors, which are preferably in the unit. However during a “warmup” phase, the vents are typically always closed, and then opened or closed based on a relative humidity set point (which may be based on a variety of factors, such as species of wood). Thus, typically the vents are closed during warmup, open during a “free water” stage of drying, and closed during the “bound water” stage of the drying process. [0039] In addition, a touchscreen display 160, controls enclosure 164, and electrical connectors may be included on the housing.

[0040] Unit 100 is configured to be directly attached to a container around an opening, and may include a wall mounting flange 172 to facilitate such attachment. Preferably, the attachment between the modular unit and the container will limit airflow through the points of attachment. As shown in FIG. 4, unit 100 is attached to a shipping container 10 and may be supported by one or more ground supports 176 (e.g., 176a, 176b). Alternatively, as shown in FIG. 5, a gusset frame 177 or similar may be used to further support the unit when attached to a container.

[0041] FIG. 5 is a cross section side view of a unit 100 attached to a container 10 via mounting flange 172. FIGS. 6-7 and 9 are detail views of the attachment points. As can be seen in FIG. 6, a backer 202 is bolted to container flats and a header 206 is bolted to backer 202 at a top edge 208 of container end wall 209. Structural screws 173 may be used to secure the flange 172 to backer 202 beneath flashing 214. Similarly, at the lower connection shown in FIG. 7, a backer 218 is bolted to container flats and a sill 222 is screwed to backer 218 at the bottom edge 226 of the container cutout area. This example configuration allows unit 100 to be secured around the opening of container 10. FIG. 8 shows a rear view of unit 100 and FIG. 9 is a detail view of an example top section connection in which a jamb leg 230 at a sill 234 notched for the jamb 230 is bolted to the container and a structural screw 173 is used to secure flange 172 to jamb leg 230 and the container at the container cutout 232 and container carrier post 236.

[0042] FIGS. 10A-10D illustrate a modular unit 100 of the present disclosure attached to a shed 20 with a cutout 22. FIG. 10C is a sectional side view of the attachment and FIG. 10D is a detail view of an attachment area, showing a header 237, sheathing 238, siding 242, flashing 244, casing 246, stud frame 248, and structural screw 250 securing the flange to the header 237.

[0043] FIGS. 11A-1 IB illustrate how lumber 15 is preferably stacked within a container 10 in order to be dried using a modular unit of the present disclosure attached to the container 10.

[0044] FIGS. 12-13 show example di splay /control panel views that users can access on the modular unit for monitoring the drying process and selecting parameters for setting up a drying session. [0045] FIG. 14 is a schematic top view of a drying system in which a modular unit 100 is attached on a side of a container 10 and holds stacked lumber 15. A fan 144 in unit 100 forces air toward one side of the unit and the flowing air (preferably heated by heaters in unit 100) moves around barrier 136 and into the container and through the gaps between lumber 15 and the container sidewall, as well as through the stacked lumber (depicted as solid arrows). When air is circulated in this direction, some outside air may be drawn in through port 120a when the vent is open (depicted as dashed arrows). As the air flows around and through lumber 15, it is cooled and picks up moisture, and ten is drawn back into unit 100 or out vent 120b when the vent is open (depicted as block arrows). When the fan direction is reversed, the air will flow in the opposite direction to promote even drying of the lumber.

[0046] In another embodiment, a modular unit 300 is shown in FIGS. 15-21B, and includes a housing 304, a front (with access panel 364 and a display screen 360), a rear side that covers an opening in the container when attached and that may include, as shown in FIG. 16, a separator plate 336, a first side screen 332a and a second side screen 332b), a first side 316a, and a second side 316b. Exterior vent ports 320 (e.g., 320a, 320b) of vent passageways 324 (e.g., 324a, 324b) may be located on the front side. Display/control 360 is located on housing 304 and may include electrical and communication connections.

[0047] As can be seen in FIG. 18, for example, container-side vent ports at the ends of vent passageways 324 are positioned to interface with air inside a container. In this way, vent passageways 324, which may be made of plastic or metal tubes, for example, provide fluid communication between air inside the container and ambient air outside the unit and the container while bypassing air within the unit 300.

[0048] The rear side includes a divider 336 that prevents airflow between the unit 300 and the container it is attached to except through openings, such as a first side opening and a second side opening, which may preferably be covered by a grille 332 (e.g., 332a, 332b) or other material that allows airflow but prevents particulates from passing. One or more air circulation devices, such as fan 344, are included within housing 304. In a preferred embodiment, fan 344 is reversible and is positioned to direct air toward first side 316a or second side 316b. In a preferred embodiment, a baffle 345 divides unit 300 into a first side chamber 352a and a second side chamber 352b (as can best be seen in FIG. 19) and includes an opening within which fan 344 is disposed. Air within unit 300 may be heated, such as with heating elements (e.g., electrical heating elements 356a-356c and or hydronic heating unit 357).

[0049] In addition, a climate sensor 361 and thermometer 363 may be included to determine air conditions within unit 300. Further, baffles 359 (e.g., 359a, 359b) may be positioned within each chamber 352 running from top to bottom at an angle from the front to a side wall in order to assist in directing air in the desired circulatory pattern.

[0050] In a preferred embodiment, the area of the container-facing vent port will cover about 10% of the area of the surrounding opening.

[0051] Vent passageways 324 may include a vent damper assembly 380 (e g., 380a, 380b in FIG. 20) that allows the vents to be substantially open or closed (or partially open) and can be controlled during the drying process to limit or promote intake or exhaust from either port according to the stage of drying, sensed conditions, and current direction of air circulation in the unit/container. Vent damper assembly 380 includes a damper 381attached to a damper connector 383 connected to a damper motor 382. Damper 381 is pivotable and sized and configured to substantially block vent passageway 324 when in a closed position and allow airflow when in an open position

[0052] In general, the vent dampeners are controlled to maintain a certain relative humidity of air in the unit/container as determined by sensors, which are preferably in the unit. However during a “warmup” phase, the vents are typically always closed, and then opened or closed based on a relative humidity set point (which may be based on a variety of factors, such as species of wood). Thus, typically the vents are closed during warmup, open during a “free water” stage of drying, and closed during the “bound water” stage of the drying process.

[0053] The term “about” when used with a corresponding numeric value refers to ±20% of the numeric value, typically ±10% of the numeric value, often ±5% of the numeric value, and most often ±2% of the numeric value. In some embodiments, the term “about” can be taken as exactly indicating the actual numerical value.

[0054] Various modifications and additions can be made without departing from the spirit and scope of this disclosure. Features of each of the various embodiments described above may be combined with features of other described embodiments as appropriate in order to provide a multiplicity of feature combinations in associated new embodiments. Furthermore, while the foregoing describes a number of separate embodiments, what has been described herein is merely illustrative of the application of the principles of the present disclosure. Additionally, although particular methods herein may be illustrated and/or described as being performed in a specific order, the ordering is highly variable within ordinary skill to achieve aspects of the present disclosure. Accordingly, this description is meant to be taken only by way of example, and not to otherwise limit the scope of this disclosure.

[0055] Exemplary embodiments have been disclosed above and illustrated in the accompanying drawings. It will be understood by those skilled in the art that various changes, omissions and additions may be made to that which is specifically disclosed herein without departing from the spirit and scope of the present disclosure.

Claims

What is claimed is:

1 . A modular unit for kiln drying systems comprising: a housing having a housing wall, a top, a bottom, a first side, a second side, a front, and a rear side, wherein the rear side is configured to be attached over an opening in a wall of a container such that the opening is encompassed by the rear side; a reversible air circulation device within the housing; a baffle disposed between the first side and the second side thereby forming a first side chamber and a second side chamber; a divider configured to prevent airflow through the divider and to cover a portion of the rear side, wherein the divider includes a first side opening and a second side opening, wherein the first side opening is configured to allow, when the unit is attached to the container, fluid communication between the first side chamber and the container and the second side opening configured to allow, when the unit is attached to the container, fluid communication between the second side chamber and the container; a first vent passageway running from the rear side to a first area of the housing wall not on the rear side, wherein the first vent passageway includes a first container-facing port at the rear side and an exterior port at the first area of the housing wall such that the first vent passageway is configured to allow airflow, when the unit is attached to the container, between the container and ambient air while bypassing the first side chamber; a second vent passageway running from the rear side to a second area of the housing wall not on the rear side, wherein the second vent passageway includes a second container-facing port at the rear side and an exterior port at the second area of the housing wall such that the second vent passageway is configured to allow airflow, when the unit is attached to the container, between the container and ambient air while bypassing the second side chamber; and a heating system configured to heat air in the housing.

2. The modular unit of claim 1, wherein the air circulation device is positioned to direct airflow towards the first side when directing air in a first direction and towards the second side when directing air in a second direction.

3. The modular unit of claim 1, wherein the baffle extends from the divider to the front and from the top to the bottom and is configured to prevent airflow between the first side chamber and the second side chamber except via an aperture encompassing the circulation device.

4. The modular unit of claim 1, wherein the first vent passageway runs only through the first side chamber and the second vent passageway runs only through the second side chamber.

5. The modular unit of claim 4, wherein the first area of the housing wall is on the front and the second area of the housing wall is on the front.

6. The modular unit of claim 1, wherein the divider extends from the top to the bottom, extends from the baffle toward the first side, and extends from the baffle toward the second side.

7. The modular unit of claim 6, wherein the first side opening extends from the top to the bottom and wherein the second side opening extends from the top to the bottom.

8. The modular unit of claim 1, wherein the first container-facing port is within the first side opening and the second container-facing port is within the second side opening.

9. The modular unit of claim 1, further including a monitor and a control panel attached to the housing and accessible from outside the unit.

10. The modular unit of claim 1, wherein the first side opening is covered by a grille and the second side opening is covered by a grille.

11. The modular unit of claim 9, wherein the monitor and control panel is electrically connected to the air circulation device and in communication with a temperature sensor and a humidity sensor.

12. The modular unit of claim 11, wherein the temperature sensor and the humidity sensor are within the housing.

13. The modular unit of claim 1, wherein the heating system includes one or more electrical resistance elements.

14. The modular unit of claim 1, wherein the heating system has a capacity of 6 KW.

15. The modular unit of claim 1, wherein the air circulation device includes a 2 HP motor.

16. The modular unit of claim 1, wherein a volume of the modular unit is less than 5000 liters.

17. The modular unit of claim 1, wherein the first vent passageway is passive and the second vent passageway is passive.

18. The modular unit of claim 1, further including a dehumidifier in the housing.

19. The modular unit of claim 1, wherein each of the first vent passageway and the second vent passageway includes a closing mechanism configured to move from an open state in which the respective vent passageway is substantially open to a closed state in which the respective vent passageway is substantially closed.

20. The modular unit of claim 1, further including a first plate in the first side chamber, the first plate extending from a top to a bottom of the first side chamber and angled between the front and the first side and a second plate in the second side chamber, the second plate extending from a top to a bottom of the second side chamber and angled between the front and the second side.

21. The modular unit of claim 1, wherein the rear side includes a flange for attaching the unit to the container.

22. A system for drying wood, comprising: a modular unit including an air circulation device, a heater, and a divider forming a first side chamber and a second side chamber, the modular unit having a front, a rear side and a baffle covering a portion of the rear side; and a container with an opening, wherein the modular unit is configured to be attached to the container such that the rear side encompasses the opening, wherein, when the modular unit is attached to the container, a first side opening in the rear side allows fluid communication between the first side chamber and the container and a second side opening in the rear side allows fluid communication between the second side chamber and the container, a first vent passageway runs from the rear side to a first area of a wall of the modular unit not facing the container, wherein the first vent passageway includes a first container-facing port at the rear side and an exterior port at the first area of the wall such that the first vent passageway is configured to allow airflow between the container and ambient air while bypassing the first side chamber, and a second vent passageway runs from the rear side to a second area of the wall not facing the container, wherein the second vent passageway includes a second container-facing port at the rear side and an exterior port at the second area of the wall such that the second vent passageway is configured to allow airflow between the container and ambient air while bypassing the second side chamber, and wherein the air circulation device is positioned and configured to direct air such that air flows from the first side chamber through the first side opening, into the container, and from the container through the second side opening into the second side chamber.

23. The system of claim 22, wherein the air circulation device is positioned and configured to direct air such that air flows from the second side chamber through the second side opening, into the container, and from the container through the first side opening into the first side chamber.

24. The system of claim 22, wherein the baffle extends from a divider on the rear side to the front and from a top to a bottom and is configured to prevent airflow between the first side chamber and the second side chamber except via an aperture encompassing the air circulation device.

25. The system of claim 22, wherein the first vent passageway runs only through the first side chamber and the second vent passageway runs only through the second side chamber.

26. The system of claim 22, wherein the first area of the wall is on the front and the second area of the wall is on the front.

27. The system of claim 24, wherein the divider extends from the top to the bottom, extends from the baffle toward the first side, and extends from the baffle toward the second side.

28. The system of claim 27, wherein the first side opening extends from the top to the bottom and wherein the second side opening extends from the top to the bottom.

29. The system of claim 22, wherein the first container-facing port is within the first side opening and the second container-facing port is within the second side opening.

30. The system of claim 22, further including a monitor and a control panel accessible from outside the unit.

31. The system of claim 22, wherein the first side opening is covered by a grille and the second side opening is covered by a grille.

32. The system of claim 30, wherein the monitor and control panel are electrically connected to the air circulation device and in communication with a temperature sensor and a humidity sensor.

33. The system of claim 32, wherein the temperature sensor and the humidity sensor are within the unit.

34. The system of claim 22, wherein the heater includes one or more electrical resistance elements.

35. The system of claim 22, wherein the heater has a capacity of 6 KW.

36. The system of claim 22, wherein the air circulation device includes a 2 HP motor.

37. The system of claim 22, wherein a volume of the modular unit is less than 5000 liters.

38. The system of claim 22, wherein the first vent passageway is passive and the second vent passageway is passive.

39. The system of claim 22, further including a dehumidifier in the unit.

40. The system of claim 22, wherein each of the first vent passageway and the second vent passageway includes a closing mechanism configured to move from an open state in which the respective vent passageway is substantially open to a closed state in which the respective vent passageway is substantially closed.

41. The system of claim 22, further including a first plate in the first side chamber, the first plate extending from a top to a bottom of the first side chamber and angled between the front and the first side and a second plate in the second side chamber, the second plate extending from a top to a bottom of the second side chamber and angled between the front and the second side.

42. The system of claim 22, wherein the rear side includes a flange for attaching the unit to the container.

43. The system of claim 22, further including one or more additional modular units of claim 22 attached to one or more additional openings in the container.

44. The system of claim 43, wherein the modular unit and the one or more additional modular units are in communications with each other.

45. The system of claim 22, wherein the container is sized to receive lumber for drying.

46. The system of claim 22, wherein the container includes no air circulation, heating, or ventilation components other than the opening.

47. The system of claim 22, wherein the container is a shipping container.

48. The system of claim 22, wherein the container is a shed.

49. A system for drying wood, comprising: a housing having a fan, a heating device, and a baffle on a rear side of the housing forming a first side aperture and a second side aperture; and a container with an opening, wherein the housing is configured to be attached to the container such that the rear side encompasses the opening and wherein the container is configured to accommodate stacked lumber such that a first side air gap and second side air gap are formed between the stacked lumber and side walls of the container, wherein, when the housing is attached to the container and the stacked lumber is in the container, the first side aperture is in communication with first side air gap, the second side aperture is in communication with the second side air gap, and the fan is positioned and configured in a first state to generate lateral airflow circulation from the first side aperture through the first side air gap, to the second side air gap, and to the second side aperture.

50. The system of claim 49, wherein, when the housing is attached to the container and the stacked lumber is in the container, the fan is positioned and configured in a second state to generate lateral airflow circulation from the second side aperture through the second side air gap, to the first side air gap, and to the first side aperture.