How much does a home ventilation system cost to run?
Want to reduce your condensation, but are concerned about how much it will cost? Home ventilation systems aren’t as expensive to run as you might think.
We figured that the best way to put it into perspective was to compare it to another appliance that runs 24/7, your fridge.
Want a simple answer?
How expensive is home ventilation to run? Our most popular system (a four room Positive3), costs about as much to run as a fridge bought in 2024.
| System | Running cost (yearly) | Best for |
|---|---|---|
| Fridge (Average 2024) |
$101 | Keeping your food cold. |
| SmartVent Positive3 (4–6 room) |
$98 | Fighting condensation in an economical package. |
| SmartVent Fresh (single unit) |
$5 | Fighting condensation in single rooms or whole homes without a roof cavity. |
| SmartVent Balance (small, 3 supply, 1 extract) |
$147* | Fighting condensation while saving energy while reducing your heating bill. |
Based on the 2024 average power price of $0.33 per kWh. Various factors will influence yearly system running costs, your power consumption will vary Please use the above values for indicative purposes only.
Want to fight condensation, mould, and allergies for the same cost as running your fridge? Book a free home assessment here.
Crunching the numbers:
Fridges:
According to the EECA (energy efficiency and conservation authority, the agency behind star ratings on appliances), the average fridge purchased in 2024 has a yearly power consumption of 306kWh. Fun fact – Fridges have become considerably more energy efficient over the last 10 years dropping over 150kWh ($50 per year) since 2014.
This, multiplied with an average power cost of $0.33 per kWh, leaves us with a yearly cost of $100.98.
Positive3 (four room):
The SmartVent Positive3 is a flexible and economical solution which is ideal for reducing condensation, moisture, and mould. Find out more here.
How much does a ventilation system cost to run? Positive3 (4 room) fans consume 85W at 100% speed, but they often won’t be running that fast. We assume that they operate at an average of 40% speed over the whole year, giving them a wattage of 34W.
There are 8736 hours in a year, multiplied by 34W (to calculate watt hours), and then divided by 1000 (to get kilowatt hours) gives us a yearly consumption of 297kWh. This means a Positive3 home ventilation system costs around $98 per year to run, coming in just under a 2024 fridge.
Fresh (single unit):
The SmartVent Fresh is a through-wall system ideal for efficiently reducing condensation, moisture, and mould in single rooms or homes without a roof cavity. Find out more here.
How much does a through-wall ventilation system cost to run? A Fresh on 40% speed consumes only 1.75W for a yearly consumption of about 15kWh, costing about $5 per unit per year. This is roughly equivalent to the power consumption of some LED lightbulbs.
Keep in mind that SmartVent Fresh units are typically deployed in pairs, but unless you have an enormous home and need 20, it’ll almost certainly be cheaper to run than a fridge.
Balance (small)
The SmartVent Balance is a well-rounded set-and-forget solution for reducing indoor moisture, mould and condensation. Ideal for bringing fresh air indoors without significantly altering the indoor temperature. Find out more here.
How much does a heat recovery system cost to run? A BAL225 (small Balance variant) consumes 51W at 40% fan speed. This equates to 447kWh, or about $147 a year making it a bit more expensive than a fridge.
*But hang on, isn’t heat recovery meant to be more energy efficient, not less? There are two reasons why it’s more efficient:
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Firstly, the Balance also functions as an extraction fan and consumes more power because it has more oomph (but you won’t also need to pay to run your bathroom fan).
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Secondly, the real saving comes from not having to re-heat the fresh air that is brought into your home.
The saving here varies significantly from region to region, but depending on your heating needs you could save between $1500-$2500 of heating bills over two years using a heat recovery system over a regular positive pressure system. More information can be found on page 5 of our product guide here.
What about dehumidifiers?
How much does a dehumidifier cost to run, and how does it compare to a ventilation system?
According to ConsumerNZ, your average dehumidifier operates at around 200 watts. Assuming you run it for four hours a day (or 1456 hours per year), it will consume 291kWh or cost $96 a year.
$96 a year is slightly cheaper than a Positive3 system, but the number is actually a bit misleading. Dehumidifiers only reduce humidity in the room they are in, whereas a ventilation system like Positive3 will reduce it throughout an entire home 24/7. This has a significant impact when fighting both condensation and mould.
That being said, there are scenarios where a dehumidifier is required (particularly in locations with significant outdoor moisture levels like wetlands).
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*It’s worth noting that our calculations here are purely based on the energy to run the fan. A ventilation system will have an impact on your heating costs, potentially reducing them due to dryer air, or perhaps increasing them as more fresh air is brought in. It depends on your location, home, and habits.
** All values discussed are indicative only. There are many factors that can influence the energy usage of a SmartVent system, including but not limited to; house type, lifestyle, power price, and geographic location. Your actual power consumption will vary.
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