Cutting greenhouse gases using heat recovery solutions

Not just better air – but a better planet🌍

What Is a Carbon footprint?

Your carbon footprint is the total amount of greenhouse gases – primarily CO₂ – generated by your daily energy use. In buildings, the biggest contributors are:

🔥 Heating systems

❄️ Cooling systems

💨 Ventilation losses

Ventilation is often overlooked – yet exhausting warm or cooled indoor air without recovery leads to significant energy waste, and consequently, higher emissions.

Why does it matter?

Buildings are responsible for nearly 40% of global CO₂ emissions.

Ventilation systems without energy recovery:

• Require more energy to reheat or recool incoming air
• Increase HVAC system workload and costs
• Significantly raise your environmental impact

In the context of Net Zero targets, ESG commitments, and rising energy prices, energy-efficient ventilation is no longer optional – it’s essential.

What can help?

At ZERN ENGINEERING, we manufacture high-performance air-to-air heat exchangers that:

 1. Recover thermal energy from exhaust air
 2. Transfer it to fresh incoming air 
 3. Operate without mixing the air streams
 4. Reduce heating and cooling energy demand by up to 40%*

(*depending on climate, system setup, and airflow – see IEA Report)

🔍 But how do we measure this performance?

We use Thermal Efficiency (TE) – the percentage of heat recovered from exhaust air and reused in supply air.

For example:

A TE of 85% means that 85% of the heat that would otherwise be lost is retained and transferred back indoors.

Let’s make it practical:

A domestic ventilation unit with 250 m³/h airflow and a 20 °C temperature difference (e.g. indoors 22 °C, outside 2 °C) using a ZERN plate heat exchanger with 85% TE can recover approximately 1.2 kW of thermal energy.

That’s 1.2 kW your heating system doesn’t need to produce – every hour.

✅ The higher the TE, the greater your savings – in kilowatts and kilograms of CO₂.

Which heat exchanger should you choose?

Let’s look at three proven technologies – and how they help in real-world situations:

🔷 Sensible plate heat exchangers

How they work: Airflows are separated by a series of parallel plates. Heat is transferred from exhaust air to fresh air through the plate surfaces – with no air mixing.

Ideal for: Homes, apartments, hospitals, and hygienic environments where air separation is critical.

Example:

In a small residential HRV unit, a sensible plate exchanger (TE = 85%) handles 200 m³/h airflow.

Result: ~1.0 kW heat recovery, cutting heating demand by 25–30% in winter – and reducing annual emissions by up to 200 kg CO₂ (with gas heating).

🔷 Rotary heat exchangers

How they work: A slowly rotating wheel transfers thermal energy – and, in some versions, moisture – between exhaust and supply air.

ZERN ENGINEERING offers three types:

– Condensation: transfers only sensible heat

– Enthalpy: transfers heat + moisture

– Sorption: enhances latent transfer using a coated hygroscopic surface

Ideal for: Medium and large ventilation systems in commercial or industrial settings.

Example:

A supermarket installs ZERN ENGINEERING rotary exchangers (enthalpy type) for 3 000 m³/h airflow.

Result: Up to 14 kW heat recovery with added humidity transfer – saving thousands of kWh and over 800 kg CO₂ annually (with electric heating).

🔷Enthalpy plate exchangers (membrane-based)

How they work: A special polymer membrane allows heat and water vapor to pass, but blocks gases and microorganisms.

Ideal for: Schools, offices, and residential buildings in humid or cold climates.

Example:

In a kindergarten with 400 m³/h airflow, an enthalpy exchanger maintains comfortable indoor humidity in winter.

Result: Lower heating and humidification needs, better comfort, and hygienic operation compliant with VDI 6022.

Ready to make an impact?

Whether you’re designing systems for residential, commercial, or public spaces – the right heat exchanger helps cut emissions, reduce energy bills, and support environmental goals.

Contact ZERN ENGINEERING to select the right heat exchanger for your project – based on airflow, climate, and sustainability targets📩