There are several types of HVAC product available for differing purposes

  • Ventilation
  • Exhaust Extract
  • Purge Extract


Sierra-CP designs and manufactures custom ventilation systems to reduce the environmental variability that can affect repeatability of results and unnecessarily extend test programs.

Designs are typically customized for each application and can include (or make provision for) heating and cooling units, generally our designs include a recirculation system which provides better control of temperatures and is more efficient.

When compared to commercial HVAC-based solutions, our expertise is particularly valuable for sizing the ventilation system components for use in engine and powertrain applications with associated high level and dynamic changeable loads.

The same principles can be adopted for vehicle, gearbox or e-machine testing, where the heat rejection levels are generally lower.

Types of Ventilation

  • Air heating and cooling options
  • High speed systems for energy removal
  • Air re-circulation to provide ‘greenest’ solution
  • Variable speed precision control
    • Full power
    • Part power
    • Maintenance
    • Comfort mode
    • Evacuation
  • CADET ventilation control TAB
  • In-cell pressure control
  • Retro-fit to existing buildings
  • Limited space applications

Exhaust Extract

Another important element of the test cell HVAC system is the exhaust extract system. This has to deal with hot and contaminated air, with residual elements of fuel. The challenges are to not influence the performance of the engine by adding an extract system.

Our design provides a drawn outlet into which the vehicle exhaust system is fed, to cool the exhaust gases somewhat additional dilution air is drawn from the test cell and mixes with the exhaust gas prior to it reaching the high temperature fan.

Typical ratios are 5:1 dilution to exhaust gas. The diluted air mix is passed through a silencer before reaching the fan and being blown out of the building using a jat cowl to project the fumes away from the building.

The extract system will be fitted with fire dampers at test cell penetrations.

The high temperature extract fans are inverter driven for added control. 

Purge Extract

For test cells burning traditional hydrocarbon fuels there is a risk of an accumulation of vapour around the lower zones of the test cell.

Whilst a ventilation system is operating this is generally sufficient to remove these vapours, however in standby there may be a risk of the levels to accumulate and pose a fire risk.

Sierra CP can provide you with a purge system, with low level ducting and an ATEX rated fan for constant extraction from these low level zones.


Our latest systems are designed to work with Hydrogen combustion within the test cell. Please see the dedicated section on this new and exciting product set, to learn about our solutions and capabilities of the systems we have delivered.