| Controlling humidity in zones during a drying process -> Monitor Keywords |
|
|
  Controlling humidity in zones during a drying processUSPTO Application #: 20060185838Title: Controlling humidity in zones during a drying process Abstract: A method of controlling humidity in each of a plurality of zones of an enclosed space during a drying process includes, in each zone, drawing air from the zone to create an air stream through a heating element and discharging the air stream into the zone; sensing the relative humidity of the air in a sensing location in the zone; in response to the relative humidity sensed at the sensing location, operating the heating element to raise a temperature of the air stream as required to reduce the relative humidity of the air in the zone to a desired relative humidity. The method reduces over-drying and increases the efficiency of the drying process. (end of abstract)
Agent: Nixon & Vanderhye, PC - Arlington, VA, US Inventors: Claude Bourgault, Larry Dancey USPTO Applicaton #: 20060185838 - Class: 165223000 (USPTO) Related Patent Categories: Heat Exchange, With Timer, Programmer, Time Delay, Or Condition Responsive Control, Having Heating And Cooling Capability, Humidity Control, Humidity Sensor Measures Humidity Of Air In Conditioned Space The Patent Description & Claims data below is from USPTO Patent Application 20060185838. Brief Patent Description - Full Patent Description - Patent Application Claims
[0001] This is a continuation-in-part (CIP) of U.S. patent application Ser. No. 10/751,455 "METHOD AND APPARATUS FOR CONTROLLING HUMIDITY AND MOLD", filed Jan. 6, 2004, the disclosure of which is hereby incorporated herein by reference. [0002] This invention is in the field of removing moisture from buildings and like enclosed spaces, and in particular methods for controlling such removal to maximize efficiency. BACKGROUND [0003] It is well known that excessive moisture in buildings causes considerable problems. Drywall and flooring absorb moisture and are readily damaged if the excessive moisture condition persists for any length of time. Interior elements such as insulation, studs, and joists can eventually be affected as well. Furthermore, mold begins to form on the damp building materials, and can remain in the structure even after it has dried, causing breathing problems for persons occupying the building. [0004] At the extreme, such excessive moisture conditions are exemplified by a flooded building. U.S. Pat. No. 6,457,258 to Cressy et al., "Drying Assembly and Method of Drying for a Flooded Enclosed Space", discloses an apparatus for drying flooded buildings that overcomes problems in the prior art. Such prior art is said to require stripping wall and floor coverings and using portable dryers to circulate air to dry out the exposed floor boards, joists and studs. The methods were slow and allowed mold to form on the interior framing, which could then go unnoticed and be covered up and then later present a health hazard to occupants. [0005] The solution proposed by Cressy is to introduce very hot and dry air into the building, indicated as being at 125.degree. F. and 5% relative humidity, in order to dry the building very quickly to prevent mold growth and allow an early return to occupants. In the apparatus of Cressy et al., outside air is heated by a furnace and the heated air is blown into the building where it picks up moisture and then is exhausted back outside. In Cressy heat from the warmer exhaust air is transferred to the cooler outside air prior to heating by the furnace, thereby increasing the efficiency of the system. [0006] U.S. Pat. No. 6,647,639 to Storrer, "Moisture Removal System", addresses the problem of extracting water promptly to prevent the formation of rot, mold, rust and the like in flooded buildings. Storrer reveals the prior art as including passive drying through opening windows, etc. and active drying using forced air (heated or not) to expedite evaporation. Storrer discloses using a blower to blow (or draw) dry air through a hose and manifolds that can be directed at a particular area that it is desired to dry. [0007] In a similar vein, U.S. Pat. No. 5,960,556 to Jansen, "Method for Drying Sheathing in Structures", is directed to drying walls with warm, low humidity air. [0008] Prior art systems for drying flooded buildings also include dessicant dehumidifiers that use a desiccant material with a high affinity to water to absorb water from the air, and refrigerant dehumidifiers that condense water out of the air by cooling it. In both of these systems, the water must be disposed of in some manner. The water absorbed by the dessicant material is removed by subsequently drying the material. The water condensed by the refrigerant system is collected in a reservoir that must be emptied from time to time or piped to a disposal area. Care must be taken that the collected water be removed so that mold does not form therein and disperse within the building. [0009] While flooded buildings demonstrate an extreme situation, excessive moisture also causes problems in other situations as well. During construction wet conditions are often present in buildings. Long periods of rain during construction, burst pipes, wet building materials (such as concrete), and like conditions can contribute to humid conditions where excessive moisture can be absorbed by joists and studs. These moist members are often covered up by flooring and drywall such that drying is prevented, and rot, mold, and the like can form. [0010] In cold climates it is also common to use construction heaters to warm buildings during construction. Such heaters that use combustion inside the building also cause a significant increase in the humidity of the air inside the building, contributing to excessive moisture inside walls and floors and the problems associated therewith. [0011] The opposite condition of excessively dry air in a building can cause problems as well. Excessively dry air can draw moisture out of wood causing warping and splitting of floors and millwork. SUMMARY OF THE INVENTION [0012] It is an object of the present invention to provide a method and apparatus for controlling the condition of air in enclosed spaces that overcomes problems in the prior art [0013] The present invention provides, in a first embodiment, a method of controlling humidity in each of a plurality of zones of an enclosed space during a drying process. The method comprises in each zone, drawing air from the zone to create an air stream through a heating element and discharging the air stream into the zone; sensing the relative humidity of the air in a sensing location in the zone; in response to the relative humidity sensed at the sensing location, operating the heating element to raise a temperature of the air stream as required to reduce the relative humidity of the air in the zone to a desired relative humidity. [0014] The present invention provides, in a second embodiment, a method of drying an enclosed space. The method comprises providing a plurality of portable heat exchanger units, each portable heat exchanger unit comprising: a fan operative to create an air stream by drawing air from an intake and discharging the air through an outlet; a fluid coil located in the air stream; and a heat controller operative to adjust a flow of fluid through the fluid coil; positioning at least one portable heat exchanger unit as an outside air unit with the intake thereof oriented to draw air from outside the enclosed space and with the outlet thereof oriented to discharge the air stream thereof into the enclosed space; positioning a plurality of portable heat exchanger units as inside air units at spaced apart unit locations inside the enclosed space and orienting the intakes and outlets of each inside air unit to draw air from the enclosed space adjacent to the inside air unit and to discharge the air stream into the enclosed space adjacent to the inside air unit; connecting the fluid coils of each portable heat exchanger unit to a fluid heater and circulating heated fluid from the fluid heater through the fluid coils and operating the fans; sensing the relative humidity of the air stream created by each inside air unit; operating the heat controller of each inside air unit to raise a temperature of the corresponding air stream as required to reduce the relative humidity of the air stream to a desired relative humidity; and allowing an amount of air substantially equal to the amount of air drawn from outside the enclosed space to exhaust from the enclosed space. [0015] Raising the temp of air 10.degree. C. will reduce the relative humidity of the air by about 50%. By sensing the relative humidity of the air at a sensing location, conveniently at the air stream outlet a heat controller can be operated to supply heat at the proper rate to achieve a desired relative humidity in the air stream, and thus in the zone. [0016] The relative humidity of the air is an indicator of how much water the air is holding, and thus how much more water it can hold. For example, in a closed room with standing water on the floor, the relative humidity would approach 100% (i.e. the air would become saturated with water) and so no more water would evaporate off the floor. Raising the air temp 10.degree. C. will reduce the relative humidity by 50%, resulting in a humidity gradient between the water and the air, and thus more water will evaporate off the floor and the relative humidity will again rise to 100%, provided no air moves in or out of the room. By bringing in a dryer air stream and thereby pushing the wet air out of the room through an exhaust, the water is literally carried out of the room by the exhaust air with the result that all the water will eventually evaporate and be carried out of the room. [0017] On a wet day for example if the outside air has a relative humidity of 100%, raising the temperature of the outside air by 20.degree. C. will reduce the relative humidity of the air stream to 25%. A relative humidity of 25% would be generally accepted to be desirable for a construction site, being neither too moist and thus promoting mold growth, nor too dry such that sensitive materials such as flooring and millwork would be adversely affected. [0018] The amount of heat required to achieve the desired temperature rise will depend on the volume of air drawn into the air stream, which could be varied by increasing or decreasing the fan speed. In any event, the relative humidity can be sensed at the air outlet, and the amount of heat supplied then varied to achieve the desired relative humidity of the outside air stream at the output. Alternatively, the humidity and temperature could be sensed at the intake, and the temperature sensed at the outlet. The required adjustment in the amount of heat supplied could be calculated, given the relative humidity of the outside air being drawn in, by determining the temperature rise required to achieve the desired relative humidity of the air stream at the outlet. [0019] Depending on the volume of the air stream and the size of the enclosed space, the relative humidity of the air inside the enclosed space will be reduced over some period of time as the dryer air stream pushes wetter air from inside the enclosed space out through open windows, doors, exhaust vents, or the like. The relative humidity of the inside air could also be sensed directly to control the temperature rise supplied by the heat source. Care should be taken however, since using such a direct control in a relatively large enclosed space could result initially in over drying of the air stream that could adversely affect materials near the outlet of the air stream. [0020] Larger spaces present particular problems for drying by flushing dry air through the space and exhausting wetter air through a vent. In a larger space there is typically some distance between the location of the dry warm incoming air and the exhaust location. As the dry warm air moves through the space it absorbs moisture and the relative humidity of the air increases and reduces its ability to absorb further moisture. Further, as the air absorbs water, the phase change from liquid water to gaseous water vapor absorbs heat, reducing the temperature of the air and further increasing the relative humidity. Thus those areas near the wet air exhaust will experience less drying than areas near the dry air input. [0021] Often buildings being dried are not well sealed, such that a considerable amount of air leaves the building through seams in the walls, or like leaks rather than through the vent. In areas near where such leakage is significant, over-drying can occur as the flow of air though the area is increased compared to other areas of the building. [0022] Larger spaces also typically include areas or zones that are separated for example by walls into rooms, by shelves of stored goods such as in warehouses, by floors in multi-story buildings, and other like obstructions to airflow through the space. Such obstructions create uneven air circulation and result in uneven humidity in the space, and thus uneven drying. The various zones of a larger space typically include areas that are wetter for one reason or another. During construction for example, certain procedures may be taking place in one zone that create significantly higher humidity than in others, such as crack filling drywall with drywall mud. Similarly where a building has been flooded, certain parts of the building will typically be wetter than others. Continue reading... Full patent description for Controlling humidity in zones during a drying process Brief Patent Description - Full Patent Description - Patent Application Claims Click on the above for other options relating to this Controlling humidity in zones during a drying process patent application. ###  How KEYWORD MONITOR works... a FREE service from FreshPatents1. Sign up (takes 30 seconds). 2. Fill in the keywords to be monitored. 3. Each week you receive an email with patent applications related to your keywords. Start now! - Receive info on patent apps like Controlling humidity in zones during a drying process or other areas of interest. ### Previous Patent Application: System for heating and cooling the interior of a motor vehicle Next Patent Application: Propellant cartridge with restrictor plugs for fracturing wells Industry Class: Heat exchange ### FreshPatents.com Support Thank you for viewing the Controlling humidity in zones during a drying process patent info. IP-related news and info Results in 7.42052 seconds Other interesting Feshpatents.com categories: Tyco , Unilever , Warner-lambert , 3m |
||
