Posted By Zyggy Turek Bryn, Whilst not being able to give you any definitive info. on de-ionisers, I had "sick-building" type issues at a large open plan office some years ago. Whilst going through the usual checklists of ventilation, humidity, etc. I came across some research which promoted the use of plants in an office environment. To cut a very long story short, we decided to go down this road & the results were startling! Staff felt better, complaints diminished, but I was never sure whether this was just a placebo effect.....but it worked!

Posted By John Dodson Its a long time since I looked at this but there was an HSE contract research report (42/1992) by Raw of the BRE which reviewed the evidence on causes/solutions for sick building syndrome which had a small section on ionisers. It concluded that 'on balance the evidence suggests they are of little benefit.' It did however say ionisers are able to deposit dust out of the air and that this may explain why the findings on ionisers are variable. It postulated that their effect may depend on how much dust is in the air and what pollutants are adsorbed on to the dust. Similar points (in fact the wording is almost identical!)were made in an earlier HSE Specialist Inspector Report by Sykes in 1988. One of the problems is that manufacturers are very selective in their interpretation of research and hence the claims for their benefits. I also recall reading a research paper which installed ionisers in varios offices. Some were put in secretly, some with a blaze of publicity and consultation with staff. Of the latter some were working as designed others were switched off (but with a red light on the facia!). There were staff surveys before and during. I believe the results found the covert ionisers had little effect but the publiced ones did whether they were working or not! Unfortunately I can't find the reference, but it is in line with Nicki and Zyggies observations.