The Cambridge team at CIBSE award-winning Building Services Consultancy Max Fordham have given Nuaire the ultimate testimonial by installing an XBC XBOXER heat recovery system in their new city centre office redevelopment.
The refurbishment is almost complete and whilst boxes are emptied and desks occupied, the consultancy’s ambitious energy reduction measures are being put to the test.
Occupying 250m2 on the fourth floor of a 1950s office block, the new premises were given a Cat. A fit out in 2011, but, without any energy improvements made, the office space required a complete upgrade to its heating and ventilation systems, glazing, and thermal insulation.
(Max Fordham Cambridge office required a complete energy upgrade)
Joel Gustafsson, senior engineer at Max Fordham has worked with Nuaire for several years and has specified Nuaire’s energy-efficient XBC XBOXER heat recovery range on a variety of projects, including high profile university developments where low breakout noise is an important factor in the choice of ventilation.
Joel explained: “I choose Nuaire products because they are reliable and the build quality is excellent. We selected the XBC fan for the office redevelopment due to its high heat exchange efficiency and low power consumption. The office is heated by direct electric and was originally fitted with 36kW of storage heaters which were swiftly removed. Our aim was to achieve zero heating and we got close with a calculated total heat loss of 4kW. The XBC was critical to achieving this. The XBC was essentially the last piece in the jigsaw after improvements to the roof, insulation and glazing.”
(The XBC Range recently won CIBSE Energy-Saving Product of the Year)
Heat Recovery Supports Innovative Glazing
The original office glazing is sliding sash windows and in order to meet building conservation restrictions Max Fordham engineers designed narrow-profile, high-performance secondary double glazing; non-intrusive in appearance. This reduced the thermal loss without compromising on the aesthetics, and the design will allow staff to remove the glazed panels in the summer and store them away making use of natural ventilation. In the colder months when the opening windows are sealed behind the secondary glazing, the heat gains within the offices should be sufficient to maintain the desired room temperatures providing that the incoming fresh air is sufficiently tempered. The Nuaire XBC employs a counter flow Heat Exchange Block which is capable of achieving this, recovering almost all of the required energy from the outgoing exhaust air.
Fully Controlled Solution
The XBC takes full advantage of Nuaire’s Ecosmart control solution, utilising multiple room based CO2 sensors, and a control interface pack to orchestrate connections to and from other devices. The system is designed to offer three distinct user-selectable modes: supply air warming, fresh air cooling and neutral, whilst automatically regulating fan speeds according to demand.
Joel explained: “The Ecosmart control has helped us create a scenario that is quite specific. It has given us control of our CO2levels, the ability to increase fan speed for ventilation free cooling during the swing seasons and the ability to interface with our heating system.”
The addition of the XBC has helped Max Fordham achieve the final 5% of their overall energy reduction plan, this equates to an ~50% reduction once the fabric improvements are taken into account. The office is now expected to run on just 2MWh per year. The success of the overall building performance in keeping to these targets will be proven over time with variables such as changing occupancy levels and weather being critical to the actual energy use.
Andrew Bott, Consultant Sales Engineer at Nuaire worked closely with Max Fordham to develop the Ecosmart control solution required to carefully regulate the system in harmony with the other connected services, and ensure that everything runs smoothly. He said: “When a consultancy as highly reputed as Max Fordham includes your equipment in their company offices you know you have a really good product.”
Find out more about Max Fordham Building Service Engineers.
Read Alex Smith's take on this ambitious project in the May edition of CIBSE Journal