Home > Axial Roof Exhaust Fans: Carbon-Steel DWT-I

Axial Roof Exhaust Fans: Carbon-Steel DWT-I

The carbon-steel axial DWT-I rooftop fan is a roof-mounted axial-flow fan with a molded axial-flow or centrifugal impeller, a fan-specific motor in direct drive, an anti-corrosion wind cap, and a metal or glass-fibre-reinforced plastic wind-cylinder base. This page reproduces the performance table and the overall dimensions table from the manufacturer’s carbon-steel page, with the page-level series claims labelled as such.

Performance table — carbon-steel page

The table below is reproduced from the carbon-steel DWT-I page. Slash-separated entries are the page's multiple operating points for that model, in page order: each model is tabled at two operating points, except DWT-I-6A, which is tabled at three, and DWT-I-11.2A, which is tabled at one. Read each row across, not down: the first power goes with the first speed, the first airflow range and the first pressure range, and the second entries go together the same way. The largest tabled row, DWT-I-11.2A, reads 7.5 kW at 960 r/min, with a volume flow of 41,000 to 53,855 m³/h and a total pressure of 275 to 205 Pa. That top flow figure, 53,855 m³/h, is this page's own figure; the FRP variant page reads a slightly lower top figure for the same model, and each page quotes its own.

Overall dimensions — carbon-steel page only

The dimensions table below uses the carbon-steel page's own five-column scheme: columns A, B, C, D and H, all in millimetres. This scheme belongs to the carbon-steel page only and is never carried onto the FRP page, whose dimension table uses a different seven-column scheme. A buyer matching a roof opening or a curb must use this table for the carbon-steel variant, and the FRP table for the FRP variant, and must not mix columns between them.

Series claims, labelled as page-level claims

The carbon-steel page states, as series-level claims: 17 machine numbers from 300 to 2400 mm impeller diameter; a series airflow of 15,000 to 220,000 m³/h; and a total pressure of 60 to 320 Pa. Those claims describe the series as the page presents it, and they are quoted here as page-level claims only. The tables above list eleven rows, DWT-I-3A to DWT-I-11.2A, and only those eleven rows carry per-model specifications. No model beyond those eleven rows is given a specification anywhere on this site, and the 17-number wording is never expanded into models that have no table row. The same page states that blades on machine numbers 12 and above are adjustable, that an explosion-proof version is available for flammable, explosive and corrosive-gas environments, and that a dual-speed motor or a variable-frequency motor and controller is available, with a recommended locked adjustment frequency of 25 to 50 Hz. Those statements are likewise page-level claims, attributed to the page, and the explosion-proof statement is treated in full on the explosion-proof page, where the limits of the evidence are set out.

Accessories listed on the page

The optional accessories listed on the carbon-steel page are a gravity or electric check valve, an anti-bird and insect net, a maintenance switch, and a centralized control box. They are listed here as options named on the page, not as included equipment: whether any of them is included with a given model, and at what terms, is a question for the inquiry. The same applies to the dual-speed and variable-frequency options and to the adjustable-blade statement for larger machine numbers — all are page statements to confirm model by model, not standard features to assume.

Applications listed on the page

The carbon-steel page lists warehouses, factories, power stations, bus stations and gymnasiums, and describes its applications as medium-to-low-pressure, high-airflow applications. That description fits the table: the largest rows move tens of thousands of cubic metres per hour at total pressures in the low hundreds of pascals, which is high-volume, low-pressure duty. A buyer whose system needs high pressure against long duct runs should check the pressure column row by row rather than assuming the series covers it, because the tabled pressures top out at 307 Pa on the highest operating point of DWT-I-10A and 275 Pa on DWT-I-11.2A.

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