Mould & indoor air
Air scrubbing and HEPA filtration
Negative air pressure and HEPA filtration, running for as long as a contained area stays open, so whatever is disturbed inside it stays inside it. This is equipment hired by the unit and by the day, priced exactly that plainly.
An air scrubber draws room air through a sequence of filters, the last HEPA-rated, and moves it outside rather than back into the room. Inside a containment it holds the space at a lower pressure than around it while cleaning the air passing through — pressure matters as much as filtration.
It is rarely bought alone. Most often it arrives alongside a mould remediation, a fire or smoke job, or crawlspace and attic work, priced per unit and per day the containment is open rather than folded into one flat fee.
What the negative pressure is actually buying you
No containment is perfectly sealed — a zipper, a seam, a gap where sheeting meets an odd opening will always leak a little air. Without negative pressure, dust leaks outward through those gaps. With it, air leaks inward instead, held lower than the pressure around it.
Exhausting outdoors rather than recirculating through the same filter is not cosmetic either. A HEPA filter is very good at what it does, but running everything back into the room asks one filter to be the entire barrier; sending the exhaust outside adds dilution as a second, independent line of defence.
Sizing it, and running it for the whole job
How many units a space needs comes from its volume and the air-change rate called for — set out in an assessor's plan, or worked out from the room on a fire job. We size it before we quote rather than guess low.
It runs for the whole time the containment is open, not switched on for the noisy work and off for the rest, because dust resuspends for hours after the last cut. Filters are changed on a schedule rather than run until they clog, included in the daily price rather than billed later.
Where else it turns up
It is not sold here as a whole-house air purifier on a subscription — if that is what somebody is offering, ask what containment it is protecting. Inside a proper containment it does exactly what it says.
On a short job it might run a single day; on a full remediation it runs as long as the containment stays open, which the assessor's plan decides, not us. It comes down with the containment, not before it.
Included as standard
What the job actually includes
The unit sized to the room
Air-change rate from the room's volume, not from the van.
HEPA filtration, exhausted outside
Air leaves the building rather than back into the room.
Negative pressure held for the whole open period
Not switched on for the messy part and off for the rest.
Filter changes included in the daily price
No separate callout to swap a filter mid-job.
Sized against the assessor's plan where there is one
The air-change rate a mould job calls for, met rather than guessed.
Placement and noise discussed with you first
It runs continuously and is not quiet. We will agree where it sits.
When to call us
Signs this is the job you need
- A contained area is being opened for removal or demolition work
- Dust or debris that needs to stay inside one room while work continues elsewhere
- A job where negative pressure is specified in an assessor's remediation plan
- Odour or fine particulate following work into rooms outside the contained area
- A crawlspace or attic job where fresh air matters for the people working inside it
- A fire or smoke job where soot-laden air needs to be kept out of unaffected rooms
Air scrubbing and HEPA filtration — what it costs
- Per unit per day, including filter changes.$180 – $340
This is the range this job actually lands in, not a headline figure. The low end is a straightforward version of the work; the high end is one with a hard access problem, an old service, or something that has to be opened up before anybody can be certain. We tell you which one you have after we have looked, and the written quote says where the price could still move and why.
Questions we are actually asked
Air scrubbing — frequently asked
Can I just hire this to clean the air in my house generally?
You can hire the equipment, but it is built to hold one contained area negative and filter what is disturbed inside it, not to purify an occupied house long-term. That is a different conversation.
How many units do I need?
It depends on the volume of the space and the air-change rate called for — set out in an assessor's plan, or worked out from the room on a fire job. We size it before we quote, not after.
Do the filters need changing during the job?
Yes, on a schedule rather than when they visibly clog, included in the daily price rather than billed as an extra. A loaded filter stops working quietly while still running.
Related work
Often needed alongside this
Mould remediation
Containment, removal and cleaning to an independent assessor's plan — never to a plan we wrote ourselves.
$2,400 – $7,800
Crawlspace & attic
The two places nobody looks, where a ventilation problem quietly becomes a remediation problem.
$1,800 – $6,400
Antimicrobial treatment
Applied to cleaned surfaces as a final step — not sprayed over a dirty one instead of cleaning it.
$450 – $1,800
Duct cleaning
The ductwork is how soot and odour reach rooms the fire never touched, and it is the step most often skipped.
$900 – $3,800Somebody who does the work will come and look
Book a visit
Telephone and you will get somebody on this crew rather than a call centre, at any hour. The emergency assessment is free inside our service area and you keep the written findings whether or not you use us. If what you describe will keep until the morning, we will tell you that instead of sending a van.