Balanced Ventilation (HRV) vs. Mechanical Extract Ventilation – what is the difference?

A healthy indoor environment starts with proper ventilation. In residential buildings, two systems are most common: mechanical extract ventilation and balanced ventilation with heat recovery (HRV). These systems are often confused, but they work completely differently – and only one of them uses filters.

Mechanical Extract Ventilation

With mechanical extract ventilation, only stale indoor air is extracted from the home. Fresh air enters through window vents, gaps, or open windows. Key characteristics:

• extraction only – no mechanical air supply
• no heat recovery
• no supply ducts with filters
• no HRV filters required

This system is usually controlled by a 3-speed switch in the kitchen, bathroom, or toilet.

Balanced Ventilation with Heat Recovery (HRV)

With balanced ventilation, also called an HRV system, fresh supply air and exhaust air are mechanically balanced. The heat from the extracted air is recovered and transferred to the incoming fresh air. Characteristics:

• mechanical supply and mechanical extract
• lower heating costs due to heat recovery
• continuous and controlled ventilation
• replaceable HRV filters present

Because both supply and extract air pass through filters, regular replacement is essential for health, hygiene, and efficient system performance. Read more.

Do I have a balanced HRV system in my home?

You most likely have an HRV system if:

• two air ducts are connected (supply and extract)
• there are two filter cartridges in cassette or panel form
• a large wall-mounted ventilation unit with a display is installed in the attic or basement
• you have no window trickle vents and the home was built according to modern building regulations

How do I find the brand and model of my HRV unit?

To choose the correct filter set, the brand and model of your balanced ventilation system is important. You can identify this in several ways:

1. Check the identification plate on the HRV unit

Almost every HRV unit has an identification plate showing brand, model, and serial number. It is usually located:

• on the back of the unit
• on one of the side panels
• behind or beneath the front cover

2. Measure your existing HRV filters

If you cannot determine the model, measure the existing filters:

• length
• width
• thickness

With these dimensions, we can recommend the correct HRV filter set.

3. Send photos to our service team

If you still cannot identify the system, simply send photos to our specialists. We will identify your HRV unit free of charge.

Helpful photos include:

• front view of the unit
• inside view with the cover open
• the HRV filters (inside the unit or removed)

You will typically receive a reply within one working day along with a direct link to the correct HRV filter set.

Need help choosing the right HRV filters?

• Send your photos and questions to [email protected]
• Measure your existing filters and email the dimensions
• Receive fast guidance and the correct product link

This ensures you order the right HRV filters for your balanced ventilation system and maintain a healthy, energy-efficient indoor climate.