Modern Building Services

MODERN BUILDING SERVICES JUNE 2021 25 FEATURE COOLING & VENTILATION VENTILATION A little over a year ago, office workers flooded out of their premises and headed home for the first of the Covid-19 lockdowns. It’s hardly unsurprising then that an estimated 60% of Brits are still working from home. Now is the time for facilities managers to start preparing their buildings for the arrival of staff again, whether in coworking spaces or as the sole tenants. Here we explore the main considerations to be aware of: Service & maintenance HVAC, or heating, ventilation and air conditioning equipment is a lot more sophisticated than it was just a few years ago. There are lots of component parts, designed to deliver maximum efficiency at high-performance, so ensuring your equipment is still up to scratch is vitally important. It is essential that everything from the calibration of temperature and pressure sensors to compressor operation and heat transfer from exchangers is regularly checked. Probably, the first thing to look at in the building is the ventilation, as increasing the amount of fresh air into spaces is one of the best ways of ensuring you keep your businesses and staff as COVID-safe as possible. It’s therefore worth asking how simply you can increase the airflow into those spaces and seeing whether your existing equipment is able to do this and do it energy efficiently, or whether you need to consider an upgrade. After that, it’s worth looking at your heating system and flushing out any water systems. Check and clean all vents on ventilation, chilled beams, air conditioning, etc and give all components, including electrics an overall system check. Check time clocks are still working if power has been off for any period and also take the opportunity to check that the set times are still relevant if you will be operating different occupancy patterns. Whatever your system it is worth reviewing whether it is calibrated to ensure maximum comfort and reliability and it’s also crucial that these systems are regularly checked, so once you’ve got your systems back up and running to cope with occupied, rather than empty spaces, it would be worth getting the maintenance team in to double check everything – even if that means bringing forward the schedule. It’s worth remembering that for those working in the office, productivity is directly linked to the temperature of the working environment. A study in the US found that workers were twice as productive working at 25‹C, compared with working at 20‹C. At 32‹C, productivity fell 85%, highlighting the importance of small changes in temperature. Indoor air quality The effects of poor air quality are well known in the outdoor environment, but less known is the impact of indoor air quality. A study in 2019 found that poor air quality can interfere with productivity, so it’s important to have a steady supply of clean air circulating through a building to ensure optimal productivity. For those buildings that do not have access to open windows or ventilation systems, units like modular mechanical ventilation with heat recovery (MVHR) or air handling units (AHU) are ideal for this task as they remove the stale air while simultaneously delivering a fresh air supply to a building. For some buildings, there will be a drive to increase the rate at which fresh air is introduced into the office – which is also what future Building Standards are suggesting. This in turn adds additional strain to the system by needing it to work at higher levels. Being mindful of the operating capacity and the time running at these levels, increased service and maintenance schedules will be required to ensure a reliable and effective system. Remote working Using a control system, facilities managers are provided with cost-effective ways of managing, monitoring and reporting on the performance of all building services systems. It’s unlikely that HVAC equipment has been running at full power while the building has been empty. Plus, unnecessary operation also reduces the lifetime of fans and other moving parts, adding to maintenance and repair costs. Ideally, HVAC systems will therefore have been kept in lower power modes where they continue to run, but without the usual demands placed on them from full office spaces. Air conditioning systems need to be able to respond to different building requirements. These include rise and falls in occupant levels and heat loads fromequipment such as lighting and computers. Be prepared Undeniably, building services such as ventilation, cooling, heating and water systems will play a central role in the health and safety – and ultimately comfort – of those that work there. While there’s certainly no full-proof guide to get through the current situation, there are a series of steps that facilitiesmanagers can take in order to prepare their buildings for increased occupation again. Facilities managers and building services maintenance teams are on the frontline of this ever-evolving situation and will continue to play a pivotal role in the ongoing service and maintenance of HVAC equipment to deliver a safe and healthy workspace. Mark Grayston , Product Marketing Manager, Mitsubishi Electric looks at some of the key areas FM’s should be looking at when preparing to reopen their offices. Breathing new life into the office