The customer approached P&I Group with concerns about a potential health and safety issue involving the exhaust systems from three on-site generators.

Exhaust fumes from the three site generators were entering the main office when windows were open, presenting a health and safety concern for employees and triggering the site’s CO₂ alarms, which had led to the building being evacuated several times.

The customer initially wanted the generators relocated to resolve the issue. However, P&I Group reviewed the situation and proposed a more cost-effective alternative: upgrading and extending the generator exhaust systems so fumes could be discharged safely above roof level.

The site had three generators located in a position where exhaust fumes could enter the office building when windows were open. This created a clear health and safety concern for the customer, particularly as CO₂ alarm activations had already resulted in multiple evacuations.

Relocating the generators would have been a major undertaking, involving significant cost, site disruption and additional logistical challenges. The customer needed a solution that would resolve the exhaust fume issue while avoiding unnecessary expense and disruption to operations.

The challenge was to design and install an upgraded exhaust system that could safely route fumes above the office and roof level, while working around the existing generator locations, site layout and operational requiremen

As an alternative to relocating the generators, P&I Group proposed extending the generator exhaust systems above the office and roof level. This approach offered a practical and cost-effective solution, achieving the customer’s health and safety objective at around half the cost of moving the generators.

Working with exhaust and scaffolding specialists, P&I Group helped develop a CAD design showing the proposed exhaust route, scaffolding positions and lifting requirements.

Detailed RAMS were produced and issued before work began, ensuring the installation could be carried out safely and in line with site requirements.

The works included the installation of three upgraded exhaust systems connected to two 500kVA generators and one 800kVA generator. The systems included 250mm ID, 310mm ID and GE30 exhaust configurations, with 21m and 33m sections of new exhaust pipework installed.

The exhaust systems were manufactured using AISI 316L stainless steel inner sections and AISI 304 stainless steel outer sections, with high-density mineral wool insulation. The systems were manufactured to BS EN 1856-1 and designed to operate at high temperatures, rated T600, and high pressure below 5000Pa.

The exhaust system upgrade was successfully completed ahead of schedule and fully tested before handover.

By extending the exhaust discharge above roof level, the customer was able to resolve the issue without relocating the generators. This provided a safer working environment for employees, reduced the risk of further CO₂ alarm activations and avoided the cost and disruption of a full generator relocation.

The project demonstrated P&I Group’s ability to assess a site-specific problem and deliver a practical engineering solution that balanced safety, compliance, cost and operational continuity.