ISO 16956-2015 pdf free.Thermal performance in the built environment – Determination of air flow rate in building applications by field measuring methods.
In the cooling and heating loads of a building, the air taken in from outside account for a large portion of the entire load; in order to estimate this load, It is necessary to correctly grasp the air flow rate of ventilation and air-conditioning systems. This International Standard stipulates the methods for measuring the rate of air flow through the ducts in a steadily operating ventilation and air-conditioning system and in the air control ports including air diffuser, suction opening, and exhaust opening.
2 Normative references
The following documents, in whole or in part, are normatively referenced in this document and are indispensable for its application. For dated references, only the edition cited applies. For undated references, the latest edition of the referenced document (including any amendments) applies.
ISO 5168, Measurement offluid flow — Procedures for the evaluation of uncertainties
3 Terms and definitions
For the purposes of this document, the following terms and definitions apply.
orifice plate
thin plate having a hole, or holes, bored through it
Note 1 to entry: These are used for measuring the difference in static pressure of the flow before and after the disc and obtaining the air flow rate in the duct by multiplying by a predetermined coefficient.
3.2 tracer gas gas used to measure its concentration varying in the air
Note I to entry: This gas is mixed with a sufficiently small amount of air so as not to affect the flow, and the amount of air is determined by measuring the gas concentration diluted in the air.
3.3 volumetric concentration ratio of the volume of the specific gas to the unit volume of the mixture of air
Note 1 to entry: It is expressed in cubic meters per cubic meters or 10-6 vol.
3.4 mass flow mass of air or tracer gas flowing in unit time
Note ito entry: It is expressed In mg per second or kg per hour.ISO 16956 pdf free download.