Constant Flow Module

iZZi 302 ERV

Constant Flow Module for the reQnet iZZi 302 ERV allows for automatic balancing of the ventilation system – equalizing the inflow and outflow air streams. Designed for self-installation inside the central unit.

What does the Constant Flow Module (CFM) provide?

The module measures the actual pressure of the installation on both the supply and exhaust sides and adjusts the fan parameters so that the amount of air supplied and exhausted is the same at any given time. The accuracy of the measurement system cannot be achieved through manual adjustment of the installation by the user or installer. Additionally, installation resistances change over time during its operation, so only continuous measurement and adjustment of performance are optimal solutions.

Why will the flows always be different?

  • The exhaust and supply installations always have different flow resistances because they are distributed differently.
  • Filters on the supply and exhaust sides accumulate dirt in different ways, generating different airflow resistances.
  • The ventilation system is influenced by the wind, which, blowing into the intake or exhaust grilles or generating negative pressure on the windward side, disrupts the air balance in the system.
  • During the operation of the recuperator, water droplets may appear in the channels of the heat exchanger on the exhaust side, which, at low operating efficiencies of the device, can clog some of these channels, generating additional resistancey.

When the installation is not properly balanced, two scenarios may occur:

1 The supply air flow will be greater than the exhaust air flow, causing positive pressure in the building. This results in decreased efficiency of heat recovery in the heat exchanger during winter because more cold air is supplied than warm air is exhausted at that time. Additionally, the pressure in the building equalizes through the “leakage” of warm air through leaks in the home.

2 The exhaust air flow will be greater than the supply air flow, causing negative pressure in the building. This results in the inflow of cold, unfiltered, pollutant-laden outdoor air through leaks into the building, leading to the cooling of rooms and increased heating demand.

What does a balanced installation provide?

The constant flow module primarily provides energy savings because only a balanced installation is able to maximize the recovery of energy from the air removed from the building, which affects reducing the energy demand for heating the house.