The company Segotec, based in Vernouillet (78), mainly provides maintenance services in the tertiary sector. As it is responsible for the daily surveillance of a data centre for one of the main internet service providers in France, Segotec cannot afford to make mistakes in its operations. The site is visited every day to check the ongoing maintenance operations.
Created before the internet boom, this data centre is located in the Paris region and hosts storage systems and telecommunications equipment. “It’s one of the operator’s nerve centres, where the most important challenges are managing air conditioning and electrical consumption” explains Mr Vincent, the Works Manager at Segotec.
On the site, there are no fewer than 50 direct expansion air handling units which regulate the temperature of the data rooms specifically. Other technical installations and offices are also cooled through different means (Rooftop, VRV, etc.). During maintenance, parts have been successively replaced, but the refrigeration circuits have started to deteriorate. This has been evidencedby the presence of acidity in certain installations which is not caused by damage to the compressor. An audit was therefore performed
by Segotec at the customer’s request and a programme of rejuvenation and renovation of the refrigeration circuits set out, in view of the importance of these systems. “Making these installations more sustainable by reducing cumbersome maintenance procedures in the future was the challenge we were looking to meet”, says Mr Vincent.
Approach to renovating the circuits
10 refrigeration circuits were to be renovated. As the units are duplicated, the air-conditioned area was not jeopardised. At most two circuits could be shut down at the same time, provided they were not too close together and the area did not overheat. In order to comply with European regulations on fluorinated greenhouse gas-based solvents, Climalife developed and formulated a new product, Nettogaz GC+, and asked Segotec if it could be tested on site.
Testing and use of Nettogaz GC+
On 30 March, one of the two circuits in the air handling unit was shut down. After draining the circuit and recovering the refrigerant R-407C, the refrigerated circuit was divided into three parts, the evaporator, the condenser and the connection pipes. Nettogaz GC+ was tested on the 50 kW STULZ evaporator, in accordance with the procedure supplied by Climalife. The GC+ circulation was activated by pulsations obtained by quickly alternating opening and shutting the valve of the cylinder so as to create a “water hammer” effect on the fluid. Very quickly, thanks to the clear flexible PVC tube which joins the evaporator to the GC+ recovery barrel, the flow of GC+ could be observed, first black then more yellowish. The oxide deposits could be seen clearly with the naked eye on the tube wall. The Nettogaz was circulated until it flowed out of the circuit clear. The cleaning took around 30 minutes and produced good results.
High-performance efficiency
The Segotec technicians were surprised but completely satisfied with the results. “It is clearly more effective and faster than the previous product or other products on the market” one of them said. This result is due to its linear cleaning capacity and its Kauri Butanol value of over 80, which proves its high performance in eliminating impurities from circuits. “Moreover, the new GC+ packaging in this Friocatch bottle, equipped with a nitrogen connector, is better suited to our requirements” said a technician. Nettogaz GC+ conforms to the field expectations and Segotec is proud to have been one of the first users.
“We always like to be involved in this kind of field test because things have to move forward, …, it’s always great to see suppliers who take an interest in the installers on site. The technicians are always happy to have the chance to participate and talk to you about their job. It opens their profession to the outside, which they appreciate” concluded Mr Vincent.