Preliminary study of the performance and operating characteristics of a mop-fan air cleaning system for buildings

• Published in: Building and environment Vol. 42; no. 9; pp. 3241 - 3252
• Main Authors: Riffat, S.B., Zhao, X.
• Format: Journal Article
• Language: English
• Published: Oxford Elsevier Ltd 01.09.2007; Elsevier
• Subjects: Applied sciences; Building technical equipments; Buildings; Buildings. Public works; Cleaning; Climatology and bioclimatics for buildings; Environmental engineering; Exact sciences and technology; Impeller; Light photon; Mop; Photocatalyst; Reaction; Ventilation. Air conditioning; Cleaning; Impeller; Reaction; Photocatalyst; Light photon; Mop; Performance evaluation; Air pollution control; Fluid dynamics; Buildings; Photocatalysis; Performance characteristic; Photochemical reaction; Fan; System description; Gas cleaner
• ISSN: 0360-1323; 1873-684X
• DOI: 10.1016/j.buildenv.2006.07.038

A theoretical investigation has been made into the performance of a novel mop-fan air cleaning system able to perform self-cleaning while circulating indoor air throughout the building space. The mop fan therefore reduces the need for outdoor fresh air and so energy for heating/cooling the air. The fluid dynamic characteristics of the mop impellers have been simulated using a model developed on the basis of previous test data. Characteristic parameters such as volume flow coefficient C Q , pressure coefficient C Δ p and power coefficient C P , are indicated as the functions of rotation speed, mop fibre number and diameter. An optimum working state is recommended for maximum static efficiency. The UV light-photon characteristics of the mop cleaning system have been simulated using a model developed on the radial-diffusion assumption, and the photochemical reaction in the system has been investigated using Langmuir–Hinshelwood kinetic theory. A room self-cleaning process has been analysed, taking into account the effect of pollutant-generating rate and air flow rate on mop reaction efficiency and self-cleaning time. It is concluded that increased mop fibre diameter and quantity, as well as enhanced light source intensity, benefit the dynamic and photochemical performance of the mop cleaning system. Increasing the air flow rate and reducing pollutant-generating rate can significantly shorten the time to achieve a steady-state condition and helps to reduce pollutant concentration in the room.