Search results
Results from the WOW.Com Content Network
The MERV scale is designed to represent the worst-case performance of a filter when dealing with particles in the range of 0.3 to 10 micrometers. The MERV value is from 1 to 16. Higher MERV values correspond to a greater percentage of particles captured on each pass, with a MERV 16 filter capturing more than 95% of particles over the full range.
MERV is a standard used to measure the overall efficiency of a filter. The MERV scale ranges from 1 to 16, and measures a filter's ability to remove particles from 10 to 0.3 micrometer in size. Filters with higher ratings not only remove more particles from the air, but they also remove smaller particles.
The Facility Guidelines Institute recommends using sequential HEPA filters for ORs with a MERV rating of 7 (i.e., captures particle 10 to 3 μm in size) and 14 (i.e., captures particles from 1 to 0.3 μm in size). [5] One mechanism by which HEPA filters capture particles is electrostatic charge.
Best Research-Cell Efficiency Chart: Image title: National Renewable Energy Laboratory (NREL) maintains a plot of compiled values of highest confirmed conversion efficiencies for research cells, from 1976 to the present, for a range of photovoltaic technologies. Software used: Adobe Illustrator CC 23.0 (Windows) Conversion program: Adobe PDF ...
To express the efficiency of a generator or power plant as a percentage, invert the value if dimensionless notation or same unit are used. For example: A heat rate value of 5 gives an efficiency factor of 20%. A heat rate value of 2 kWh/kWh gives an efficiency factor of 50%. A heat rate value of 4 MJ/MJ gives an efficiency factor of 25%.
When talking about the efficiency of heat engines and power stations the convention should be stated, i.e., HHV (a.k.a. Gross Heating Value, etc.) or LCV (a.k.a. Net Heating value), and whether gross output (at the generator terminals) or net output (at the power station fence) are being considered. The two are separate but both must be stated.
MPR is different from MERV, the Minimum Efficiency Reporting Value. The MERV system measures a filter's ability to capture large particles. The MPR only takes into account the microscopic particles between 0.3 and 1 μm.
A specific model of a generator operated as a standby generator may only need to operate for a few hours per year, but the same model operated as a prime power generator must operate continuously. When running, the standby generator may be operated with a specified - e.g. 10% overload that can be tolerated for the expected short running time.