IESI is an advantageous application in the recovery of thermal energy of the fumes produced by different combustions or production processes such as: smelting furnaces, heating furnaces, heat treatment furnaces, food production ovens, glassworks, cogeneration and trigeneration systems, generators or other situations, which normally envisage the waste disposal of energy resources into the atmosphere.
The core of the IESI consists of a monoblock thermal group, consisting of "Patented" AISI 316 stainless steel plate-type exchangers, which can be dismantled to allow extraordinary maintenance.
IESI in its operation, as a heat energy recovery unit, is crossed by the hot fumes that strike the plate-type exchangers and convey the available heat to the water with temperatures that reach up to 110°C and with a recovery of the thermal energy up to 90% and above of the source.
Via the recovery of the sensitive heat contained in the fumes and of the latent heat (if condensation is required), it is possible to increase the overall efficiency of the system by up to 107%, thus being able to take advantage of the economic benefits provided by the specific regulations or tax benefits.

Operating Principle


It only works at the pressure and flow rate of the fumes induced from the source.
For correct operation, it is necessary to adequately size and install:

  • All the components that interact between the heat source to be recovered and the new use of the recovered heat.
  • An electronic control system, which is used to control the components that interact between the heat source to be recovered, the STATIC IESI and the management of the recovered thermal energy in output, so that it is constant both in flow and in temperature.
  • Install all the systems necessary to secure the heat recovery system.


It is equipped with an appropriately sized fume exhaust fan which is used to obtain an adequate flow rate and head, to guarantee constant heat recovery over time.
It is set up in its entirety based on the system design and is equipped with all the safety systems and electrical / electronic, mechanical, hydraulic, management and control systems.
IESI DYNAMIC is particularly suitable where low heat source conditions prevail.




Additional Kits

Modul Power Kit

it is a combined system of energy modulation valves (2 or 3-way), which safely modulate the quantity of energy to be recovered at the input of IESI, controlled by an electronic management system, which acts both on the quantity of fumes aspirated, keeping the flue gas temperature constant at the inlet, and depending on the modulation at the regenerator outlet, through a mixing water outlet system. This kit is essential to supply Genius absorbers with hot water recovered at constant temperature, or other types of applications that require constant temperature hot water.

Thermal Rescue Kit

it is used to guarantee constant thermal power in IESI output in the event that the source of the heat energy to be recovered is intermittent or insufficient to supply the expected utilities such as: radiators, fan-coil, AHU for heating, or absorption systems fuelled by hot water for the production of cold water, etc.

Cleaning in 3 easy steps

A clear advantage of IESI is the particular cleaning method designed to make routine maintenance operations simple and fast, necessary to maintain performance efficient and constant over time.
All this is even more evident, when the primary energy sources generate solid combustion residues (e.g. Diesel, biomass, ...)

1Switch off IESI and remove the inspection panels

2Clean the heat exchangers with a simple pressure washer

3Replace the inspection panels and start IESI

Remote management of an IESI installation

At the customer's request, energy recovery operators that use IESI can be supplied with remote management for remote control.
The remote management software is built ad-hoc for the customer and allows constant control of the various components, with activation / deactivation as well as analysis and monitoring functions.