What is a Subfloor?

I'm sure you know that dark, damp space beneath your home. Remember you left those surfboards you bought back in 2004 down there, never to be seen again...

Well that's your Subfloor and, without proper Mechanical Ventilation, it can be the cause of mould growth or musty smells in your home.

Because it isn't a liveable element of your home, this space can easily be neglected. However this space may have some of the biggest impact on the indoor air quality of your home, unknowingly affecting the health of you and your family. If that doesn't seem bad enough; lack of subfloor ventilation can also lead to significant & costly structural damage to your home.

This is because, being it is so dark and damp down there, mould and moisture get trapped inviting pests, risking wood rot of timber flooring and/or supports and allowing contaminants & musty odours to creep into your home.

Unfortunately, because of the fantastic job your builder probably completed to achieve an airtight, well insulated & sealed home (great for energy efficiency), your home cannot breathe and methods of natural ventilation probably aren't cutting it.

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So, what's the solution? How do we treat poor ventilation of the Subfloor?

Firstly, it's important to understand the "mathematics" to achieve proper ventilation. But don't worry, when it comes to your project, we will take care of the numbers.

There are two vital elements to effective ventilation of a Subfloor. In order to achieve the suggested 4-5 air changes per hour (in a standard subfloor*), methods of exhausting and supplying air must be utilised to achieve proper ventilation.

*where a subfloor is experiencing significant dampness, holds excess moisture or other special conditions - up to double the suggested air changes may be required

Exhaust Air

For example: let's say your home's floor plan was a perfect square

Step One: Calculate Square Meterage

In this case 10m x 10m = 100m^2

Imaginary Floor Plan

Now let's imagine your Subfloor was at a perfect height of 2m all the way across - this is the ultimate dream for our 6ft2 sparky

Step Two: Calculate Volume

In this case 100m^2 x 2m = 200m^3

Imaginary Subfloor Height

Let's find a fan which will achieve 5 air changes of this complete volume.

Step Three: Calculate Required Capacity

In this case 200m^3 x 5 air changes = 1000m^3 OR 278 L/s

Blauberg In-Line Fan

Therefore, this subfloor would require1 of our BLAUTURBO200 in-line fan capable of 1080m^3 per hour.

See our product page here for more fans

Now that we've chosen our fan, Comfort Zone will develop a customised Ducted System Design to target troubled zones/rooms and extract from multiple strategic points, to draw air OUT of the Subfloor to atmosphere.

Supply Air

Passive methods of ventilation are most common and ideal for most Sydney homes. Those Terracotta Louvre or Square Vents you might've painted over during your last home 'spritz' did have a purpose.

If functional, these vents allowed fresh flowing air into the Subfloor. However, they aren't the best available & they are easily obstructed and/or damaged.

To supplement your Mechanical Subfloor Exhaust Air System, we replace all existing vents and strategically install new Mesh Vents (as seen below) to introduce this fresh air to your Subfloor once more.

Mesh Vent Installations Completed by Comfort Zone

As the air is exhausted out of your Subfloor, via the fan, pressure decreases to allow fresh air to be pulled through these vents creating that cyclic pattern which achieves... light bulb moment incoming... AIR CHANGES!

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Okay, information overload over. Let's summarise.

What is a Subfloor?

Your Subfloor is the supporting structure of your home. It is the open space beneath the floor of your home where all the foundational walls & structures live to evenly distribute weight across your home. It is grounded on a raw environment of soil, sandstone, rock & more.

Why is it important to be treated and looked after?

This space is almost always neglected by the home builder & owner due to lack of education on its impacts and needs. Being it is such a dark damp space, mould and moisture get trapped inside inviting pest, risking wood rot or timber floors/joists/supports and allowing contaminants & odours to creep into your home. This unknowingly affects the health of you and your family but can also lead to significant & costly structural damage to your home.

Why does it require mechanical ventilation?

Though you may not utilise your Subfloor, your builder definitely did when they built your foundations and put in your ducted Air-Con or In-Floor Heating System. This means there are a multitude of obstacles for air to get trapped during attempts to flow through any relief vents or weep holes present.

How do we ventilate it?

At Comfort Zone we Supply & Install complex custom ducted Subfloor Systems like below.

The benefits to a ducted subfloor system are:

• It can be targeted to reach the depths of your subfloor or more troublesome zones

• Provides the opportunity to extract air from multiple points - up to 6 with our single fan systems & 12 with our dual fan

• Equipped with volume controlling dampers which mean custom settings to suit the needs of your subfloor space

This system is 'Set & Forget' where we electrically connect it to mains power, programmed by a local or remote 24-hour control timer. We will set it to your best suited 12-hours of the day typically 7am-7pm - as running the fan during the day has the advantage of drawing in daytime air which is typically warmer with better drying qualities. Also, during this time, occupants are usually out of the home which means noise will not be heard or will be drowned out by general ambience.

What are the Signs & Symptoms of a poorly ventilated Subfloor?

• Damp/musty smells in your home

• Mould growth on walls and/or furniture against walls

• Mould growth on cupboard contents

• Recurrent cold, allergy or asthmatic symptoms

• Your Pest or Building Inspector suggests more ventilation (no they aren't just trying to spend your money)

• Wood decay, rotting bearers/joists, floor cupping and/or bending

The Mechanical Subfloor Ventilation System we've presented to you throughout this read is typical to most Australian homes and other buildings (such as shopfronts, restaurants, offices, schools & chapels) which have a suspended timber floor.

Array of Fan Installations completed by Comfort Zone

Contact our office or Submit An Enquiry to speak to a member of our staff and arrange a quote, inspection or find out more about what Comfort Zone has to offer.

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FAQ

How much will it cost?

At Comfort Zone we've designed a costing catalogue for all our standard Systems & Services. For a Comfort Zone Quality Subfloor Ventilation System we offer the following standard "packages":

• Single Fan System with 6 extract points (suited to most average Australian homes) - priced at $3,900 (including GST and labour)

• Dual Fan System with 12 extract points - priced at $7,000 (including GST and labour)

• Supply Air Mesh Vents can be replaced or installed from $138-$185 per vent (including GST and labour)

Although all prices listed here are subject to complete site inspection with all necessary trades.

How loud are the fans?

To get technical, our standard Subfloor Fan the BLAUTURBO200 has a noise level rating of 46dB@3m. This means nothing to the average person however.

Included in all our standard Subfloors, fans come complete with our Noise & Vibration Control system including:

• 2 x Silencer Attenuators 500mm long - custom designed to reduce noise emitted by fan motor/air flow through fan blades

• 4 x Anti-vibration Rubber Fan Mounts - engineered to eliminate vibration of the fan motor travelling through the floor joists which we mount onto

• 1 x Acoustic Sound Lagging Wrap - made by the same companies who create sound proofing panels for studios & cinemas, it is wrapped around the fan to further capsulate sound emitted by the fan motor

We cannot speak on your individual noise sensitivity, however, you SHOULD NOT BE ABLE TO HEAR THE FANS over typical ambient daytime noise. This is why we schedule your Subfloor Fan/s to run from 7am-7pm when:

a) most people are out of the house to school or work

b) there is typically other noise occurring throughout your home or externally which will be louder

Can I get a fan which pushes air into my Subfloor to force the air out instead?

As a general rule of thumb YOU SHOULD NEVER PUSH AIR INTO A TYPICAL SUBFLOOR. This is because you may end up pulling in potentially dangerous contaminants or additional moisture into the Subfloor space also.

Of course all rules come with exceptions where, in the event, Comfort Zone will manage a method of Mechanical Air Supply complete with a Filter system to ensure the above does not occur.

What if we just replace the existing vents to introduce cross-flow ventilation?

We all know that climate conditions have changed significantly over the years, and as this continues to change, the demands to keep your home breathing do as well.

This means that those original terracotta louvres installed circa 1960s, or even earlier, will not cut it in today's time. In the same way, simply installing 'extra' vents will also not improve conditions for the following reasons:

• Unless wind is flowing directly into the vents, they are unlikely to provide sufficient air exchange on their own to begin with.

• Additionally, your Subfloor holds the foundations of your home which means there are many internal structural walls which completely block the pathway through, making it hard for air to travel around.

• Finally, in the age of ducted Air-Con and In-Floor Heating, your Subfloor may be housing a lot of additional duct, mechanical systems and electrical services which depletes the chance of 'natural' cross-flow ventilation all together.

Ultimately, we will respect any decision our clients make to improve their home and living. However, if you HAD to pick one or the other, we'd urge all our clients to proceed with Mechanical Exhaust Air Systems over the installation of new or remediation of existing wall vents.

You installed my system yesterday and I can smell mustiness more than before.

Remember that 6ft2 Electrician I mentioned earlier on, well during your Subfloor installation he was walking, crouching and crawling around to complete this project of ours.

Because he's stirred up a little bit of Subfloor soil, you may experience an initial musty smell. However, with the fans running on their 12-hour schedule, this should clear up within a week.

Why choose Comfort Zone?

Rest assured knowing that Comfort Zone has the Legal & Experience based support to provide our services.

We are equipped with a Contractors License to complete Minor Trade Work, Worker & Public Liability Insurances and our lead installer is a fully licensed electrician who undertakes the management & completion of your project. Ask us for our Licenses & Accreditations here. And as members of the Master Builders Association, you can be sure we have the trust of our industry leaders & partners.

We invite you to read our Reviews & Testimonies accrued over our 26-Year of business.

And if that isn't enough to convince you, have a read of the following article and see how we unpack the contents of a competitors quote vs our own to break down the difference between the best and the rest. Comfort Zone in 'The Best VS The Rest'.