Crawl space ventilator fan

Details Crawl space ventilator fan Crawl space ventilator fan

1999-10-28

2002-10-22

Walberg, Teresa (Department: 3742)

Pumps

Motor driven

Including means for facilitating assembly or disassembly of...

C454S239000

Reexamination Certificate

active

06468054

ABSTRACT:

BACKGROUND—FIELD OF THE INVENTION
The present invention generally relates to a unit which exhausts air from the crawl space area of a dwelling or other building with a space below the sub-floor, and more particularly, relates to a ventilator with an improved installing and mounting means which is low voltage, thus having the ability to be wired through standard irrigation timers.
BACKGROUND—DESCRIPTION OF PRIOR ART
Many structures are built with underlying air space under the sub-floor, which for the sake of convenience, will be called crawl space for the purpose of this application. These crawl space areas can accumulate substantial amounts of moisture due to poor drainage of the soil, environmental factors such as rainfall and humidity, and even landscape irrigation. This excessive moisture, causes humidity to build and provides a breeding ground for mold, mildew and biological contaminants which are known to cause asthma as well as other severe allergic health problems. In fact, the Consumer Federation of America calls our sick houses the “number one health and safety issue of our time” adding billions of dollars annually to the nation's health bill. Contaminants under the subfloor build, and eventually permeate into the dwelling itself, causing air pollution inside. This indoor pollution is believed responsible for the huge increase in hospitalizations for Asthma—an increase of 50% for adults and 200% for children in the past 20 years. Not only does excessive moisture in crawl space areas under buildings lead to health problems, it also promotes rot and decay in the wood substructure and rust to any metal members, such as jackstands, support brackets, etc., costing billions in water damage repairs annually. Also, many naturally occurring gases and odors can occur under these buildings, and without the aid of a ventilator to allow them to escape, they can build to dangerous levels. Among the most dangerous of these gases is Radon, which is considered to be the most serious cancer causing agent in the environment. In combination, these contaminates can have synergistic effects, compounding the health risks further.
In many of these structures, particularly more recently built dwellings, there is a very low rate of air exchange between the air in the crawl space and the air outside the dwelling. This is due in part to recent trends towards high energy efficient construction. These practices involve the use of insulations to make the dwelling more tightly sealed, and sealing cracks and other air leaks to prevent heated or cooled air from escaping, and outside air which requires heating or cooling from randomly entering at an excessive rate. In effect, such houses and buildings become, to various degrees, closed systems. The result of an insufficient inlet fresh air volume flow rate into, and out of, such tight enclosed spaces is that contaminants accumulate inside to health affecting levels. To emphasize this point, it is estimated by some health care researchers that presently two persons per hour, in the United States alone, contract lung cancer as a result of contact with Radon in poorly ventilated houses and other buildings.
Most buildings with crawl space areas rely on passive air to circulate the air from inside the enclosed space under the sub-floor to the outside environment through openings in the foundation walls. Passive systems rely on environmental conditions, such as the wind, which is neither constant nor provides important exhaust air flow.
To deal with this problem, a number of ventilators have been created to assist in exhausting the air from the crawl space area through various methods. A search of existing Patents shows that numerous inventors have realized the need for a method to provide inlet fresh air to crawl space areas under dwellings and have proposed various systems, and methods of their use.
Many of these ventilator units, either the unit itself or it's housing, must be mortared in place in the foundation wall at the time it is constructed, and are therefore not suited for installation in a pre-existing situation, such as in existing constructions. Some of the ventilators are permanent installations, either the unit itself or its housing, and once installed, cannot be removed without the assistance of a person skilled in masonry techniques. Many of the ventilators require access underneath the sub-floor for installation. This requires a person the difficult and time consuming task of maneuvering in a crawl space area for the purpose of installing the ventilator, increasing the need for a professional. Other ventilators require permanent or “hard” wiring, requiring the skills of a professional electrician, further increasing the cost of installation.
Many of the ventilators in the prior art function on passive air flow and have no means for exhausting the air actively. These passive ventilators are designed with either a simple screen or a system of louvers that open and close to let air pass through. A number of ventilators were found to utilize either temperature sensing devices or humidity sensing devices, or both, causing an increase in manufacturing costs as well as creating a higher chance of unit malfunction due to the complexity of these devices. A few of the ventilators with a louver system were controlled to open and closed either with a solenoid or bi-metallic element, or temperature sensitive compression spring.
Following is a brief description of the prior art found in the patent search. There are ventilators that rely on a passive system to move air through as discussed above. These include U.S. Pat. No. 4,699,045 to Robert C. Hensley, Oct. 13, 1987 in which he discloses a thermostatically actuated ventilator with adjustable louvers and separate support frame that is to be frictionally mounted in an opening of a foundation wall.
Another passive system is that of U.S. Pat. No. 4,821,628 to Paul M. Sarazan Jr. and Dennis A. Beam Jr., Apr. 18, 1989 which discloses a shallow profile foundation ventilator consisting of a decorative molded frame with screening for mounting within an opening in a foundation wall, which is mostly intended for aesthetic purposes.
Another passive ventilator system discovered in the prior art is U.S. Pat. No. 4,274,330 to Alfred E. Witten and Howard W. Green, Jun. 23, 1981 in which is disclosed a ventilator with a separate mounting frame which said ventilator slides therein. This ventilator is also decorative, and mainly for appearances only.
A passive ventilator that must be permanently installed with mortar in a foundation wall during construction is disclosed in U.S. Pat. No. 5,460,572 to Arthur L. Waltz and David A. waltz, Oct. 24, 1995.
Disclosed in U.S. Pat. No. 4,493,456 to Paul M. Sarazan and Dennis A. Beam, Jan. 15, 1985, is another passive ventilator that includes a system of inter-connected louvers that open and close in response to a thermally responsive spring.
U.S. Pat. No. 4,175,480 to Dennis A. Beam Jr. and Paul M. Sarazan Jr., Nov. 27, 1979 discloses a passive ventilator with adjustable louvers with a support frame that connects to an opening in masonry walls.
In yet another invention, U.S. Pat. No. 4,290,554 to Robert C. Hensley, Sep. 22, 1981 discloses a temperature actuated foundation ventilator that also has a system of louvers controlled by a bimetallic element that responds to changes in temperature to move a control link that extends into the housing, into pivotal engagement to open and close said louvers. This ventilator is permanently installed with mortar into the foundation opening.
U.S. Pat. No. 4,587,892 to Alvin E. Witten and Erik H. Witten, May 13, 1986 discloses a passive ventilator in which it utilizes a compression spring to frictionally mount within a crawl space opening in order to keep the mounting frame secure as it contracts and expands in response to changes in temperature. It includes a shutter system that opens and closes in response to temperature changes.
A more simple passive design is that of U.S. Pat. No. 4,711,160 to Alvin A. Witten and Erik H. Witten,

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