Issue link: https://www.e-digitaleditions.com/i/1386104
54 I ICT TODAY Firestop Pre-formed Device Pathways: Air Tightness at 40% Cable Fill Pressure [Pa] Airflow per device [m 3 /h] 0.0 10 25 50 75 100 150 5.0 10.0 15.0 20.0 25.0 30.0 35.0 40.0 45.0 50.0 Testing compared 4" Firestop cable devices with 40% cable fill (57x Cat 6 cables); both devices installed acc. to manufacturer IFU. Leakage measured @ 21⁰ C; 52-57% RH and tested acc. to EN 1026. Airflow in [m3/h] measured for over-and underpressure; chart displays average values. How can this challenge be addressed initially and throughout the life cycle of the data center? To start, designers should consider planning for firestop system pathway/sleeve technology with approvals and airflow control performance for an empty sleeve or pathway that allows up to 100 percent visual cable fill. This design practice can help better address correct installation throughout the life cycle of the building. Newer tech- nologies, such as firestop cable pathway devices, have been developed as all-in-one fire and air resistance solutions allowing for the "empty to full" capacity conditions. The built-in fire and airflow resistance technology enhances initial and long-term code compliance and risk mitigation concerns. BEYOND FIRE PROTECTION Addressing minimum firestop code compliance is a first essential step. However, does simply specifying any solution and relying only on initial inspection really address all challenges? It is important to reflect and consider all potential issues from MEP penetrations. Thus far, airflow control in terms of fire and smoke migration has been discussed, but what about air leakage risks when no fire occurs? What about limiting airborne dust and whiskers or controlling data hall pressurization? Furthermore, conditions, such as building movement and acoustics, are realistic challenges that designers should consider. Can the selection of certain firestop systems help address these additional concerns? Do firestop system technologies differ regarding perfor- mance of these attributes? To address these questions, a brief summary of airflow control is helpful. Airflow As discussed, a key goal of firestop systems is to limit the passage of smoke and toxic gasses. How can overall air leakage be measured? Two key variables that impact air- flow control results are: the desired room pressure levels and the percent fill of cables per pathway opening. As part of the UL 1479 test standard, Underwriters Laboratories offers a procedure to evaluate system air- flow resulting in a listed "L-rating." This test is conducted at 75 o F (≈24 o C) and 400 o F (≈204 o C) while maintaining a pressure of 75 Pa or 0.30 inches water column (0.30 WC). With industry needing to provide a balanced approach to fire protection, achieving various levels of data hall pressurization are critical due to proper oper- ation of fire suppression systems. Additional testing can be conducted to establish air leakage results at multiple pressure levels. For data cables, increasing percent fill capacities over the life cycle of a data center can also impact air leakage performance. Figure 5 shows that code compliant firestop solutions can still have significant differences in airflow control performance. The third-party air leakage testing, shown in Figure 5, was conducted at multiple pressures with cable pathway fills of 40 percent and shows a significant performance difference between pathway devices. Device A restricts air FIGURE 5: Air leakage testing graph.