Filtration is a ubiquitous technique used for removing particulates and other unwanted matter from any type of fluid or gas. For example, in many heating, ventilation and air conditioning (HVAC) systems, air (and other fluids and gasses) are filtered to remove debris within an enclosed space of a temperature-controlled environment. In the case of HVAC systems, for example, as the air is circulated, an air filter collects and traps particulate matter which is later removed via either filter replacement or cleaning. A dirty or loaded air filter places a strain on the air movers of the HVAC system, which can cause increased power consumption, reduced airflow, mechanical stress on the motors of the air movers, and shorter system life expectancy. In some instances, air filters are physically inspected to determine if maintenance or replacement is necessary. In other instances, air filters are replaced at scheduled intervals, even if the air filter does not necessarily need to be changed. Often, air filter replacement and/or cleaning does not take place at proper intervals, and overall system performance is negatively impacted.
Likewise, liquid and gas filtering systems are an integral component in the gas and oil industry, and in other systems that involve the removal of contaminants from a flowing stream of liquids and gases. For example, in automotive and industrial applications, fluid filters are used to remove particulates from motor oils (e.g., using an oil filter), refrigerants, coolants, and brake fluids. In the case of industrial applications, many companies spend significant time and resources on monitoring, scheduling, and replacing dirty oil and coolant filters, and on repairing damage that occurs from overly dirty fluid filters.
Moreover, the nature of filtration is changing due to the changing nature of forced fluids and air systems. In particular, whereas in the past, air and fluids were either being driven, or not, in modern systems, air and fluids are more often being driven at variable speeds and forces. As a result, existing techniques are insufficient for determining filter loading by measuring an amount or extent of clogging or dirtiness.
Accordingly, a need exists for a system to accurately determine the status of filters by determining an amount or extent of clogging or dirtiness of fluid/air filters in a variable flow environment.