Fans and Blowers

Industrial fan and industrial blower — difference and working principle

An industrial fan moves large volumes of air — even several thousand m³/h — at low operating pressure, usually up to around 500 Pa, and provides general air exchange in a hall, warehouse or workshop. An industrial blower generates higher pressure, often above 2 kPa, and pushes air through a flexible duct over distance — into a tunnel, excavation, well or shaft, where a standard fan cannot reach.

At NORWIT.PL we carry primarily fans and blowers from Master Heaters, Trotec and Heylo — from compact axial fans to three-phase 400V units for large halls, plus professional blowers for tunnels. Equipment from one of these brands is on the Master Heaters page. Below we explain the difference between an axial and a radial fan, how to size airflow to a room, and 230V/400V power supply.

Types of fans and blowers — range segments

The range splits into four segments: general hall ventilation, portable construction fans, tunnel/duct blowers, and units that support drying. The table below lists equipment type against application and brands.

This category has no subcategories of its own — all heating, cooling and drying equipment for construction sites is in the parent department heating and cooling.

Axial vs radial fan — difference in construction

The choice comes down mainly to impeller construction — an axial fan moves large volumes of air at low pressure, while a radial (centrifugal) fan generates higher pressure at the cost of lower airflow. The table compares both constructions.

Applications — construction sites, halls, tunnels and excavations

On a construction site, a fan or blower forces air exchange where there is no natural draught: in foundation excavations, wells and shafts several to over a dozen metres deep, removing exhaust fumes from construction machinery, dust and excess moisture. Longer spaces, such as tunnels running 20–50 m, need a blower with a flexible duct — the range includes, for example, the Master BLM 4800 professional blower. Halls are usually designed for 6–10 air changes per hour, and 15–20 air changes/h where dust or fumes are present — several smaller fans placed around the perimeter of a hall give a more even airflow than one large unit.

Fan and blower use when drying a building

A dehumidifier on its own, in a large or poorly ventilated room, only dries the air effectively in its immediate surroundings. A fan or blower positioned facing the dehumidifier forces air to circulate between the unit and damp walls, floors or ceilings, which can cut drying time by around 20–30% at the same dehumidifier output (typically 20–100 l/24h). This combination works well after flooding and when drying screeds. Dehumidifiers suited to this use are in the condensation dehumidifiers and desiccant dehumidifiers categories.

230V and 400V power supply — output and portability

Smaller and medium fans and construction blowers run on standard 230V single-phase power, available from a typical site socket, and draw usually up to 1–2 kW — enough for ventilating a single room, an excavation or a short tunnel section. Larger units with airflow rated in thousands of m³/h need three-phase 400V power (a 16A or 32A socket), because a motor rated at 3 kW or more requires an appropriately sized cable and overcurrent protection.

Frequently asked questions about fans and blowers

Why buy fans and blowers at NORWIT.PL

We carry fans and blowers primarily from Master Heaters, Trotec and Heylo. We help with choosing the right type (axial or radial), sizing airflow to room volume, and picking the right power supply (230V or 400V), and when drying a building we help put together a set with a dehumidifier matched to the situation. Orders are processed online, with shipping across the country.