Why is energy efficiency not regulated in car parks?
Do fans need to run continuously at 3 or 6 ACH at all times?
In a typical enclosed car park the fans can be running continuously at 3 or 6 ACH to control build up of vehicle exhaust fumes or spilled petrol fuel when the car park is in general use, as required by Approved Document F. But why run fans even at 3 ACH if there are no vehicle movements?
Too much focus on initial costs often leads to higher energy costs in operation
An emphasis on lowest initial cost means that very often there is no consideration of the huge costs of running a ventilation system over the lifetime of a car park, and the CO2 emissions associated with this.
Energy efficiency and costs can be cut in several ways
There are several ways to reduce running costs by running the fans at a lower speed or even by switching them off altogether during periods of low car park use. This can be achieved either by using inverter controls, by installing a more accurate sensor system, or by measuring other aspects of air quality than simply CO – why not monitor levels of particulate, NO or NOx?
The issue is that all of these measures are voluntary
If the Building Regulations are not catching up with the times, the ErP regulations under Regulation (EU) No. 327/2011 will soon do. These come into force from 2015 and set out minimum fan efficiencies for both day-to-day ventilation and smoke fans.
Whilst dual-purpose fans are popular because of reduced installation and maintenance costs, they, as all fans, will need to be more energy efficient than hitherto. A key feature of any fan in a high temperature application is higher running clearances, allowing for the expansion of the blade and housing materials under the influence of heat. This makes such dual-purpose fans inefficient when running in day-to-day mode. As a result with some schemes it will make sense to have two dedicated fan systems, which is likely to make it easier to achieve higher energy efficiency.
Download the latest version of our leaflet covering ventilation systems for car parks, loading bays and service areas, which brings legislation and standards up to date.
Conor Logan is a Technical Manager of Colt UK, Smoke and Climate Control Division. Conor designs innovative smoke control and HVAC systems and is also Chairman of the Smoke Control Association.