7 Del. Admin. Code § 30-5.0
Current through Register Vol. 28, No. 3, September 1, 2024
Section 30-5.0 - Procedure5.1 Determine the equivalent diameters of the NDO's and determine the distances from each VOC emitting point to all NDO's. Determine the equivalent diameter of each exhaust duct or hood and its distance to all NDO's. Calculate the distances in terms of equivalent diameters. The number of equivalent diameters shall be at least four.5.2 Measure the total area (AT) of the enclosure and the total area (AN) of all NDO's in the enclosure. Calculate the NDO to enclosure area ratio (NEAR) as follows: Click here to view Image
(D-30-1)
The NEAR must be <=0.05.
5.3 Measure the volumetric flow rate, corrected to standard conditions, of each gas stream exiting the enclosure through an exhaust duct or hood using EPA Method 2. In some cases (e.g., when the building is the enclosure), it may be necessary to measure the volumetric flow rate, corrected to standard conditions, of each gas stream entering the enclosure through a forced makeup air duct using Method 2. Calculate FV using the following equation: Click here to view Image
(D-30-2)
where:
QO = the sum of the volumetric flow from all gas streams exiting the enclosure through an exhaust duct or hood.
QI = the sum of the volumetric flow from all gas streams into the enclosure through a forced makeup air duct; zero, if there is no forced makeup air into the enclosure.
AN = total area of all NDO's in enclosure.
The FV shall be at least 3,600 m/hr (200 fpm). Alternatively, measure the pressure differential across the enclosure. A pressure drop of 0.0075 mm Hg (0.004 in. H2O) corresponds to an FV of 3,600 m/hr (200 fpm).
5.4 Verify that the direction of air flow through all NDO's is inward. Streamers, smoke tubes, or tracer gases may be used. Strips of plastic wrapping film have also been found to be effective. Monitor the direction of air flow for at least one hour, with checks made no more than 10 minutes apart.7 Del. Admin. Code § 30-5.0