Positive pressure systems

The Consumer guide to positive pressure systems.

Ventilation systems   positive pressure systems hero default

Here's what you need to know about positive pressure systems.

How they work

Want to read the full article?

  • Heaps of buying advice so you can choose with confidence
  • Independent reviews of thousands of products and services
  • Personal advice an email or phone call away on our advice line (members only).

Solar-powered ventilation systems

What to look for

Ventilation systems

Ventilation systems

Ventilation systems promo img default

Ventilation systems

If your home suffers from streaming windows, mouldy curtains and a damp unhealthy feeling, you need to improve your ventilation. We explain how to stop the sources of moisture and what to look for in a ventilation system.

Learn more

Member comments

Get access to comment

roy s.
20 Oct 2018
Moisture Master system.

Years ago we had a Moisture Master system fitted to our poorly insulated ex-state brick house, which had aluminium joinery fitted to replace the original wooden windows. The house was damp in the winter with small mould buildups in the bedrooms. We had a 2 outlet programmable heated system fitted and within ten days it was like we had a new house. No condensation,and after we cleaned up the mouldy areas,it never came back.
More importantly, the bronchial problems that both of our small kids had developed, also went away. I cant speak highly enough of the service we recieved,and the system did everything that Moisture Master said it would.
Not only that, but the cost was just over half of what HRV wanted and the filters were a third of the price.
Moisture Master were also a lot cheaper than DVS.
I was still recieving calls from pushy HRV sales people months after i had told HRV that i had gone with a different system. Do your homework!

Robert W.
23 Sep 2018
No off switch

I have the SAYR system, and my neighbour the HRV. In both there is no master switch to turn off the power, say, if you are away for a few weeks. You have to turn off at the circuit board (along with maybe the fridge), or go up into the attic. Yes, you can turn off the fan at the controller, but it turns back on within 24 hours. I suspect all systems are the same.
On a different issue, the neigbour’s HRV seems to do a better job at filtering the air than my SAYR. Sigh 😔.

Chris B.
07 Jul 2018
Solar powered vetitlation systems

Hi,
You mention " We’ve found only one solar-power model suitable for a typical-sized New Zealand house, and it’s quite expensive", but you don't mention what it was or what the addtional price difference was. Are you able to supply further details on this? Thanks Chris

Consumer staff
09 Jul 2018
Re: Solar powered vetitlation systems

Hi Chris,

Solar energy heating/ventilation systems use solar energy that has been absorbed by solar panels to heat fresh supply air that runs through the panels. Solar cells can also be used to power the supply air fan. These systems are very energy-efficient but quite expensive to install in houses. SolarPro (https://solarpro.co.nz/) heats the air that then gets pumped into the house. This can be retrofitted onto an existing system as well. This is a solution for the winter months and cannot really be considered solar powered, it rather captures the energy to heat the air.

There are also numerous solar powered fans available an example can be found here: http://www.hometech.co.nz/residential/ventilation/solar-star-roof-fan/ They are probably better suited to situations where you find your roof cavity is getting really hot during the summer and you are struggling to cool your house.

The problem with solar powered ventilation is that you want to be continually ventilating your house. The period of time when you are generating the most moisture i.e. cooking the evening meal or having showers all usually happens when the sun has gone down. Your best bet if you want to go down this path is to consider a grid-tied solar array. This will power a ventilation system for free when the sun is shining and will continue operating as per normal on cloudy days/during the night.

Kind regards,
James - Consumer NZ writer

Consumer staff
05 Jun 2018
Re: HRV System

Hi Angela,

Glad to hear you are enjoying the benefits of your home ventilation system. I have seen replacement filters advertised online at a price much cheaper than the $390 that HRV charge, they sit at around the $60/filter mark. I think that $390 is pretty expensive but you are paying for the convenience of having someone else do it and take away the old filters for disposal. $390 adds about $0.53 to the daily cost of having the system in place. Every dollar you save with the DIY approach further reduces this number. You can do the filters yourself but you will need to have the means to get into the ceiling, the confidence to isolate the power and be suitably handy enough to make the filter change.

Cheers,
James – Consumer NZ writer

Angela T.
03 Jun 2018
HRV System

We have had a HRV ventilation system for 3 1/2 years and I highly recommend it. We have an 80s linen board aluminium joinery home and had damp and condensation in the winter. This is no longer a problem and we appreciate the cooling on hot summer nights and the warm air coming into the house from the roof space during autumn and spring (advantages all year). It is automatic and don't have to touch the control unit but we can adjust the temperature and turn on the fan manually if needed.
Appreciate the tip for cheaper filters as the last replacement filters (x2) through HRV cost $390.00, recommended replacement is every 2 years. Is that expensive? Angela T.

Kirsten B.
18 Nov 2017
A great resource

Thanks so much for putting together this summary -- you have addressed all the questions that have bugged me about which, whether to install in our 50s bungalow.