Some advice before reading overseas website information…

1. The NZ Standard for indoor air quality is NZ Standard 4303 – “VENTILATION FOR ACCEPTABLE INDOOR AIR QUALITY.”

2. To see a copy of NZS4303 visit your local library, or purchase one from Standards New Zealand (call 0800 782 632),  We asked Standards NZ if we could reproduce parts of it for this website, but the answer was NO because the standard is copyright, no part of NZS4303 can be legally copied.

3. NZ Standard 4303 is literally, and almost word for word, USA Standard ASHRAE 62-1989. So wherever you see the reference ASHRAE 62-1989 it is the same as for the NZ Standard 4303. This is why USA articles on IAQ are appropriate to NZ ventilation problems EXCEPT …

4. When reading USA articles, identify the geographical location — if the location is in a State that has a climate similar to NZ, then the article will be valid — if the article is in a location that has no relevance to our NZ climate, then treat it with caution… Eg … Alaska, Ontario, Florida, are not typical of our NZ climates but San Francisco, Atlanta, are quite similar to NZ.
The year round average temperature for Christchurch is 12ºC and for London 12ºC

5. In the USA references you will note mention of HRVs and ERVs. – An ERV is similar to an HRV, (but more expensive), and specifically designed to be used in places where the climate is not typical of NZ — for example, the North East coast of the USA is extremely dry in winter, (10% RH is common, causing lips, noses, eyes and skin to dry out) – in these places it is necessary to add humidity to ventilation air and humidifiers are a common household appliance in these climates.

Our NZ climate is exactly the opposite — our climate is too moist — we need to reduce humidity. For our climate an HRV (that is specifically designed for NZ) is the most cost effective and energy efficient method to dehumidify and ventilate a home. Most overseas HRVs will not perform satisfactorily in NZ, because the Heat Exchanger has to be designed for our climate. 

Some overseas articles on HRVs refer to “freezing up” of the HRV.
This is not a problem with the CLEANAIRE HRVs — They are designed to avoid Freeze Up – even in our ski field conditions where we have several installed as ski lodge ventilation and for drying clothes and ski-boots.

6. You will also notice articles on mould and bacteria that grows in humidifiers – in the USA its known as humidifier fever – this is a condition that is very applicable to NZ – not to Humidifiers but to Dehumidifiers – the inaccessible plates and water collection systems in dehumidifiers actually support and grow mould and fungi. NEVER under estimate the health danger of dirty plates and water collection systems in a simple domestic dehumidifier, which harbour mould and fungi. Scientific tests in NZ have identified a host of very dangerous mould and fungi thrive inside dehumidifiers. If yours is an old machine, take it to a refrigeration service depot, and have it stripped and disinfected and cleaned at least once a year.

7. Stachybotrys is a fungi that has caused many infant deaths in Ohio USA – to the best of our knowledge there has never been a case in NZ.

8. RADON is a gas that is common in the USA where it leaches from the earth under homes. There is scarcely any radon in New Zealand. Minor amounts have been recorded in the Reefton Area. The most recent authoritative report that we know of is available from the National Radiation Laboratory and is titled Natural Radiation in New Zealand Homes (Ref: Report NRL 1988/6 ISSN 0111-753X)

9. WHAT is ASHRAE ?? – ASHRAE is the “American Society of Heating, Refrigeration and Air Conditioning Engineers”. ASHRAE was established in 1899, and has become the single most authoritative source of information on its title subject. Spending nearly US$100m, per annum on research, ASHRAE standards are accepted throughout the world, by both private industry and Governments. See

HEALTHY HOUSE INFORMATION — Mould in your home (A MUST SEE) — Very good IAQ resource — IAQ & Energy efficiency ideas for New Homes — Is your home making your Sick ?? — Energy Myths Revealed — Healthy home info — Is your home sick?? — How to remove mould & mildew from furniture


MOULD & FUNGI — See Mould & Dust mite articles


VOCs (Volatile Organic Compounds)

The EPA is the US Govt Environmental Protection Agency, who maintain a large website containing many relevant articles these are links to just a few: — all about Formaldehyde — all about VOCs — excellent article & Links — Sick Building Syndrome

Another very good site is the US Govt. National Institute of Environmental Health. Check out their articles about VOCs contained in insulation materials and household cleaners: — VOCs in household cleaners — Excellent article on VOCs & effects


ALLERGY & ASTHMA DATA — The Allergy & Asthma Network, Mothers of Asthmatics — American Lung Association— American Lung Association of Washington — Canadian Lung Association — helping your child to manage asthma — USA Govt. Site on asthma — USA Govt. Site on child health — The Mayo Clinic (do a search for Asthma) — The American Medical Association (do a search for Asthma)


DUST MITES — Pictures and descriptions of various mites — dustmites and other domestic residents — Dust Mite Info — Dust Mites


AIR FILTRATION — USA Govt. Article — Bacteria & Bugs that pass through Air Filters — US Govt Information pages on air filters


GENERAL — Popular Mechanics Magazine – HRV article — University of Minnesota, Dept. of Environmental Health on IAQ this is the search engine for the USA’a National Library of Medicine, run a search for TWAR and find out how widespread this disease really is —New airborne strain of Chlamydia discovered. Worldwide research reveals links between Chlamydia Pneumoniae(TWAR) and lower respiratory tract infections and heart disease.


0800 DRY AIR  (0800 379 247) 


Products are New Zealand made by Avon Electric Ltd.


Avon Electric Ltd
25 Taurus Place, Bromley
P.O Box 19748, Christchurch 8030 
Ph: 03 381-5595  - Fax: 03 381-5596