A pilot study on the effect of one room mechanical ventilation with heat recovery (MVHR) units on house dust mite populations and Der p 1 levels in laboratory simulated bedrooms and on ambient conditions in an occupied bedroom in Cambridge, UK

Abstract

A one room mechanical ventilation with heat recovery (MVHR) unit was tested on experimental bedding for survival of house dust mites and Der p 1 allergen levels in simulated bedroom conditions (February‐April 1995). Its effectiveness was also tested in a real bedroom in daily use, during the mild and damp British winter from December 1994‐February 1995. Experimental beds were artificially contaminated with approximately 1000 mites and samples obtained, using sticky traps to collect mobile‐mites, at 4 weeks and 8 weeks incubation in ventilated and non‐ventilated rooms. A sample of the mite population was also taken from a single‐bed in daily use, before and after running the MVHR unit. Results were compared longitudinally as well as transversely with those from non‐ventilated rooms. The MVHR unit in the real bedroom was run at a trickle operation mode, approximately 0.75 air changes/h, but air exchange in the experimental bedroom was maintained at 3.5 air changes/h by operating at the boost level. Data on ...