CASE HISTORY: The first implementation of advanced control electronics - 2.0 version - on multi-pipe units for 4-pipe systems with Multi-Manager.

In 2014 a full-inverter multi-pipe system was installed for a new office building, in Pont Saint Martin (Aosta), one of the most important plant projects in Italy.

For the comfort of the new open-space offices, in Pont Saint Martin, two full-inverter 4-pipe units were chosen, the perfect solution to satisfy the simultaneous hot and cold thermal loads required in the same building.

The system is designed to supply several air handling units and fan coils, for the air conditioning of offices areas and it is able to develop a total cooling capacity of approximately 1620 kW and a heating capacity of 1728 kW.

For many years, the building was occupied only partially, this is the reason why only one of the two multi-pipe units was enough to satisfy the thermal loads required by the plant. When the unit was installed, in fact, the system was equipped with a centralized control that simply sequenced the units, ensuring the optimal balance in terms of operating hours, since there was no need to share and manage the total capacity delivered by the system.

It was a preliminary version of the software that has been improved with significant implementations and changes over the last 5 years, allowing us to win the most difficult challenge: developing a sophisticated and intelligent controller able to monitor and manage a modular system in a flexible and customizable way and to choose the most efficient operating mode according to the required thermal load.

This is how the MULTI-MANAGER system was born, designed to offer customers many possible combinations of operation.

In 2018, with the arrival of new companies in the remaining part of the building of Pont Saint Martin, the air conditioning building's needs changed, because the total capacity required by the plant increased, as well as the variability of the required loads.

Hence, a new need arises: a more precise and complex management of the system is required, namely a cascade control of the units able to regulate the operation of each single units to obtain an optimal allocation of the system loads by balancing the capacity among them, in order to guarantee an increase of total efficiency of the system.

The customer requests a real upgrade of the centralized control.

The Thermocold Control Systems Development team promptly responds to the customer's request, with an intervention made to update the control electronic of the unit. During the inspection an advanced version of the software, 2.0 version, was installed and, for the first time, the Multi-Manager, a centralized system that allows the management of a group of modular hydronic units, was introduced on a 4-pipe system.

The installation of the new 2.0 version of the software permitted to obtain greater flexibility thanks to the additional features introduced, including:

• leaving water temperature control,
• improvement of defrosting,
• possibility of managing the multi-pipe system in automatic or manual mode (cooling only mode or heating only mode),
• customization of the automatic mode, setting the system operation by priority:

1. PRIORITY ON COOLING: automatic maximization to meet the cooling load demand,
2. PRIORITY ON HEATING: automatic maximization to meet the heating load demand,
3. PRIORITY ON MAXIMUM LOAD DEMAND: automatic maximization to meet the highest load demand (either heating or cooling),
4. PRIORITY ON HEAT RECOVERY: automatic maximization of the heat recovery rate.

This 2.0 software update, combined with the installation of the MULTI-MANAGER, allowed to extend the above-mentioned benefits to the whole system and therefore to fully satisfy the need of the client, who was asking for a flexible and, at the same time, efficient system. For this installation, the AUTOMATIC MODE activation was therefore suggested with priority on HEAT RECOVERY.

"In case of simultaneous cooling and heating loads, by setting the automatic mode with priority on heat recovery, the MULTI-MANAGER automatically activates the 4-pipe units in total recovery mode, optimizing the percentage of recovery and ensuring, therefore, the maximization of energy saving".

Thus explained Eng. Fabio D’amico, Thermocold Controls leader, who after having examined the client's requests and studied the load profile of the building, proposed the installation of the MULTI-MANAGER.

The combination of these two innovative Thermocold technologies - modular control and inverter multipipe units - has made the project absolutely exclusive and avant-garde. In this way the Multi-Manager advantages are added to the advantages ensured by the multipipe inverter units, guaranteeing a precise regulation of the cooling and heating capacity according to the real loads required by the plant and exploiting the excellent benefits in terms of energy consumption resulting from the heat recovery.