The summer/winter reset is upon us again, and companies can now look to set up scheduled reset timers and reprogram their hours of operation. For companies operating in temperate climates, this is the perfect time to take advantage of changing weather conditions and reduce energy waste.
Building managers, it is time to re-think the foolish obedience of BMS schedules. Long, warm summers and early autumn months can send your building’s energy usage into complete disarray. Most commonly we see Air-Con on manual override, and your heating being pumped out of open office windows. The following are some suggestions on what to look at during this transitional time period:
Corridor and stairwell temperatures should be maintained at approx. 16⁰C; ideal for free cooling i.e. neither too hot nor too cold in corridors. Set VAV and Air-Con to lowest air change rates.
This singular action will reduce the energy consumption of a 20,000 m2 building by 6%, for the seasonal changes occurring throughout the spring and autumn months.
Although equatorial regions will not have the option of ‘never cooling’ their corridor stairwells, temperate climate regions will be able to use this method as a simple energy saver. Assuming corridors will not fall below 16⁰C for comfortable working environments; buildings should allow temperatures to rise to ambient levels in order to determine corridor temperature. Companies can heat corridors and stairwells when cold, but beware of cooling them. Instead, utilise free cooling through good ventilation management.
By re-setting Sept 1st to a lower solar aspect, companies can reduce the cooling requirement of the building fabric. If however, sudden spikes or clear days occur, they can have approximately 100 watts of sensible heat gain per meter squared of building fabric. To smooth out these spikes, it is recommended that changes to settings are performed on a week to week basis, rather than pre-setting for worse winter conditions.
The last solution of energy saving in multi-sites is about storage heating. Many organisations with multiple sites have utilised storage heating as a cheap and simple method for meeting local demand without the expense of capital infrastructure. More often than not, storage heating will turn ‘on’ on a particular date in September regardless of local conditions. To reduce energy waste put in place an end of week and start of week program to start and stop heating when not required. An upgrade to a seven day management local timer or a system such as EnAct that will allow you to schedule these devices remotely as many times as you like and store them in a PLC, will also reduce energy waste in turning off heating for weekends out of hours.
These are just a few good practice points for energy saving in these transitioning seasonal months. But the major message your company should take away should be, to reset your buildings settings for what is appropriate for your building now.