High levels of extraction are often critical in laboratories (labs) to ensure containment of potentially hazardous substances. The level of extraction required is dependent on specific criteria of the substances and processes within the lab, legal requirements are comprehensively detailed within HSG258.
The level of extraction demands supply air (or make-up air) to be introduced into the lab to ensure a controlled level of ventilation ensuring a safe level of air quality/risk of exposure.
The result is a high air change rate within the lab typically in the region of 15 air changes per hour or higher. This high air change rate needs to be controlled within specific parameters for occupancy comfort (or even critical parameters for test criteria) in terms of air volume, distribution, heating, cooling, humidification, dehumidification, filtration, and pressurisation strategies.
This high dynamic load can consume very high levels of energy resulting in high running costs, it is therefore essential for the correct air handling, air distribution, temperature, humidity, and control to be selected to optimise efficiency in order to minimise cost whilst achieving the required system performance/environmental conditions.
Ambient has a wealth of experience of these types of applications and the design of systems to achieve optimum performance of such demanding applications, whilst minimising the HVAC plant to limit the capital investment wherever possible and implicate efficient controls – optimising/reducing the overall energy consumed.
Solution For Site – Thornton Ross (pharmaceutical manufacturer)
Ambient designed, supplied, installed and commissioned a variable volume HVAC system capable of suppling volumes of air equivalent to the extract volume on demand. As such, if a fume cupboard is not in use or the sash is closed or even partially closed for a period of time reducing the extract volume, then the supply system will react by reducing the volume of air supplied automatically, thus reducing the energy required to condition the air and minimising running costs. This is achieved by employing pressure controls and inverter-driven fan technology.
The plant size/cost is optimised by employing reverse-cycle heat pump technology (in coordination with adequate pre-heating) to utilise/manipulate the (dual cycle) cooling plant for the majority of the heating process, reducing the required boiler capacity and optimising the use of the most efficient heat medium whilst minimising the size of the boiler plant which in turn reduces the capital cost.
In combination with customised controls that adjust to the changing ambient condition and utilising efficient air distribution design, this project offered real value engineering for a typically larger and costly installation.
The system achieved close control of the labs’ required environmental condition whilst ensuring the extraction/fume containment operated within the designed specification, and continues to minimise energy consumption year round.