ventilation systems

Purpose of the work

Improve the effectiveness and performance of ventilation systems. Are there hygienic concerns regarding a ventilation system?

Method of approach

Practical experience as an expert in the field

Content of the contribution

Indoor pollutants and particles pose a threat to human health as people spend 90% of their time in indoor spaces. A proper ventilation system should be able to remove indoor air pollutants, reduce particle depositions, at the lowest energy consumption by that system. In this work, particle concentrations and depositions are presented for two ventilation configurations (1) Displacement Ventilation (DV) and (2) the conventional ceiling supply and return.

This overview focuses on model based control strategies for ventilation in nearly zero energy buildings (nZEB) where slower reactions towards disturbances are expected as a result of high insulation and air tightness of the building envelope (Killian and Kozek 2016). Furthermore, internal heat gains have a higher impact in these kind of buildings. In addition, occupancy pattern can be variable (e.g. in office- and school buildings) and HVAC control is consequently more challenging.

This study evaluated the emission characteristics of ultrafine particles emitted during material extrusion type 3D printer, called Desktop 3D printer, operation in the test bed and mock-up environmental conditions respectively. For the measurement, a condensation particle counter (CPC) and scanning mobility particle sizer (SMPS) were employed. In the test-bed evaluation, representative materials widely used nowadays such as ABS, PLA, TPU, PC, etc, emitted higher than the UFP criteria (3.5 ×1011) of 2D printer test method RAL-UZ 171.

The British Standard Code of Practice, and other authoritative guides, recommend minimum rates of ventilation related to the size and use of rooms, and structural means for providing them. But the difficulty of measuring actual ventilation rates suggests that it is seldom done.