Measuring and testing – Sampler – sample handling – etc. – Plural parallel systems
Reexamination Certificate
2000-10-03
2002-07-30
Raevis, Robert (Department: 2856)
Measuring and testing
Sampler, sample handling, etc.
Plural parallel systems
Reexamination Certificate
active
06425297
ABSTRACT:
BACKGROUND OF THE INVENTION
1. Field of the Invention
The invention relates to the field of environmental air management and control systems. More particularly, the invention relates to systems which sample indoor environmental air to make periodic or continuous quality measurements, including for example chemical composition, temperature, and pressure.
2. Related Art
Over the decades of the 70's, the 80's and the 90's, people have become much more energy-conscious than ever before. Among other things, this has driven the construction industry towards building structures which are far “tighter” than their predecessors, with respect to air leakage. Building designs are carefully made to provide occupants with precisely metered exchange between the indoor and outdoor air. The exchange between indoor and outdoor air is selected to provide a healthy quality of indoor air, with a minimum of energy usage for heating or cooling the outdoor air introduced. However, inevitably the tradeoff sometimes results in unacceptable indoor air quality. Moreover, the use of new building materials having many superior and desirable properties in both renovations of old buildings and new construction sometimes aggravates the air quality problems because they outgas undesirable substances. Since indoor air quality problems have a direct effect on the health of occupants of a building, there is now great interest in determining the air quality in various structures.
In laboratory settings, including chemical laboratories, biotechnological laboratories and semiconductor fabrication laboratories for example, many harmful chemicals are used. Fume hoods are used to confine and remove any harmful chemicals which may be introduced into the room by an experiment or process. Fume hoods are specially designed, confined structures in which an air flow is set up to exhaust away from a human operator any harmful substances introduced into the air. Proper operation of a fume hood requires that the air flow setting be appropriate for various parameters, including the size of the opening through which the operator may need to manipulate equipment in the hood, the supply of makeup air into the laboratory room in which the fume hood is located, and the type of materials and experiments being performed in the hood, for example. Fume hoods therefore typically include a controller which responds to various settings and determines a proper air flow through the hood. The controller then sets appropriate valve positions, fan settings, etc. to achieve the desired air flow setting. However, if a human operator improperly sets a parameter in the controller, or if the controller or a controlled element fails, then the proper air flow may not be set, resulting in a “spill” of some substance from inside the fume hood into the indoor air of the human operator. Such a spill may have a minor effect on indoor air quality or may be extremely hazardous, depending on the nature of the substance spilled and the size of the spill. Detecting spills quickly is important both for evacuating areas in a timely manner if required, and for correcting the problem which caused the spill in the first place.
Both of the areas of concern discussed above have resulted in a great deal of work in the area of measuring indoor air quality. A wide variety of sensors are available, for measuring temperature, humidity, CO2, CO, volatile organic compounds (VOCs), smoke, various other chemical contaminants, particulate levels, dust, animal odors sch as caused by rat urine proteins (RUPs), etc.
In one prior approach, shown in
FIG. 10
, to the problem of measuring indoor air quality, remote sensors for each of the substances or parameters of indoor air quality desired to be measured are placed at each site of interest within a structure. In one variation, the sensors may simply record their measurements locally, for later collection while in another variation they may be connected through electronic wiring to a central data collection system.
One major problem with local data collection is that it is useless for real time control, since the data is not available, except when collected. With a remote sensor system having central data collection, the data is available whenever the central system polls each particular sensor. However, another major problem with remote sensor systems is that they require the use of a multiplicity of expensive sensors at the individual sites to be measured. The expense is very high and the system is fairly inflexible. If a new parameter needs to be measured throughout a structure, a multiplicity of new sensors need to be installed at all the relevant sites.
Another approach to the problem, shown in
FIG. 11
, is a multiple point, sequenced system including a central computerized sensing system having a plurality of input ports connected via hollow tubes to each room of interest. A vacuum system is used to draw air samples through the tubes from each room down to the central sensing system, where a single sensor suite sequentially performs measurements on each of the air samples obtained. This system is far less expensive than those described above because it only uses one set of sensors. It is also far more flexible, in one sense, because there is only one sensor suite to be changed, if the measurements desired should change.
However, this approach is still relatively inflexible and expensive to install because of the large bundle of individual sensing tubes which must be run from the central sensing location to each site from which a sample is desired. There is also a cost associated with unused capacity held in reserve to receive additional sensing tubes at the central computerized sensing system, should potential changes to the structure requiring additional sampling sites be implemented. Such changes are common in both office and laboratory settings, where space is frequently divided and consolidated as the goals and tasks of organizations change.
Yet another conventional approach to this problem is a centralized sensing system having a single sample tube. The sample tube is snaked through the building to each space where it is desired to take an air sample. A hole is made in the sample tube at each point where an air sample is desired to be drawn from. However, such a system is extremely limited since the system makes a single, “mixed” measurement of the air drawn in through the holes in the sample tube. In other words, this system uses the sample tube as a mixing chamber in which the air drawn in through the holes is blended or homogenized into a single sample. This system lacks the capability to make individual measurements of the air drawn in through each separate hole. Rather, averaged measurements of desired parameters are made.
SUMMARY OF THE INVENTION
Therefore, it is desired to provide an air sampling system which solves the above noted problems. It is desired to provide an air sampling system which provides data to a central system, whereby building elements affecting air flow near a sampling site may be controlled in response to changes in local air quality. It is desired to provide an air sampling system in which installation costs are relatively low and flexibility is relatively high.
Embodiments of the present invention can be installed in parallel with the electrical and pneumatic networks conventionally used in modern construction. Hence, installation cost is kept low. In many installations, Phoenix Controls Corporation electronically controlled valves or other electronically controlled valves or airflow controls will be used throughout. In such cases, an embodiment of the invention may use the valve sites as junction sites. Some inexpensive system components may even be preinstalled at other junction sites in anticipation of future expansion. By so doing, great flexibility is achieved at minimal cost.
Various aspects of the present invention described below address these concerns and such others as will become evident to those skilled in this art.
According to one aspect of the invention, there
Aircuity, Inc.
Raevis Robert
Wolf Greenfield & Sacks P.C.
LandOfFree
Networked air measurement system does not yet have a rating. At this time, there are no reviews or comments for this patent.
If you have personal experience with Networked air measurement system, we encourage you to share that experience with our LandOfFree.com community. Your opinion is very important and Networked air measurement system will most certainly appreciate the feedback.
Profile ID: LFUS-PAI-O-2861658