1. Saving HVAC energy
through better air filtration
for healthy indoor
environments
Ronald Wood PhD BSc.
Innovative Plant Technology

2. Why not breathe clean,
pollutant free indoor air.
 20% saving in energy use,
 6 – 26% increase in work performance
 3 - 5% ventilation cost reduction
 12 – 18 months payback period

4. CASE STUDY
•
• Umow Lai - Consulting Engineers, Melbourne,
5 Living Wall air filters over 2 floors
• Independent testing of duct outlets after two years of
continuous operation.
• low levels of VOCs (at or below detection limits)
• very low microbial count
• higher levels of fresh air
• overall 13% improvement in productivity

5. Living Wall air filtration
 Proven low-tech natural remediation
 Removes particulates, VOCs, virus, bacteria, fungi
 Small footprint
 Low energy use
 Works 24/7

6. WHY THIS?
• lower ventilation rates in existing buildings
• no need to over-size HVAC in newly designed buildings.
• Free-standing or incorporated into air handling
• Complements existing filtration
• Complies with AS 1668-1.2 2012 Part 2 Appendix D
cleaning recirculated air

7. Schematic make up of an indoor air biofilter Image courtesy of Nedlaw Living Walls Inc

8. COST PERSPECTIVE
• Breakdown of a typical office building operating
cost structure:
 Salaries are over 80% of business costs
 Rent is around 15%
 Remaining costs ~ 5% energy, water and maintenance

9. PAYBACK 1
• Example
• Two biofilter walls each 2.4m wide x 1.7m high ~ 8 m2 are
installed in an open plan workspace of NLA 450 m2
• cost - $20,000 ($2500 per m2)
• (workplace density of 10m2/person (AS 1668.2) provides
clean filtered air for up to 45 occupants).
• Simple Payback Period - straight line approximation
• Payback Period (years) = $ Capital investment
$ Annual Savings
• Occupancy rate of 20 persons, and a 1% improvement in
performance, average salary cost $72,000 (ABS, May 2012),
Saving $720 per person = $14,400
• Payback Period 16 months

10. PAYBACK 2
• Similarly at a full occupancy rate of 45 persons the payback
period would be around 6 months.
• There are additional energy savings from reduced ventilation
rates, lower filter pressure drop, and less maintenance and
replacement costs of HVAC fans, filters and pumps and by
avoiding design over-sizing.
• Biofilter maintenance costs equate to $6.70/m2floor space/p.a.
or approximately $150 per person per annum at an occupancy
rate of 20 persons, or $67 for 45 persons.
• Clearly minimal costs compared to potential savings.

11. QuickTime™ and a
decompressor
are needed to see this picture.
Filtered air distribution Image courtesy of Nedlaw Living Walls Inc.

12. Next Steps
• To discuss how iplant Living
Wall Biofilter systems can
enhance your buildings and
bring value to your tenants and
clients, contact Dr. Ronald Wood
• Innovative Plant Technology
• e-mail iplant@plantscleanair
.com