Saving HVAC energy through better air filtration

for healthy indoor environments

Ronald Wood PhD BSc.

Innovative Plant Technology

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

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

Living Wall air filtration

Proven low-tech natural remediation

Removes particulates, VOCs, virus, bacteria, fungi

Small footprint

Low energy use

Works 24/7

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

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

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

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

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.

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Filtered air distribution Image courtesy of Nedlaw Living Walls Inc.

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