Running mean temperature
When people are dissatisfied with their thermal environment, not only is it a potential health hazard, it also impacts on their ability to function effectively, their satisfaction at work, the likelihood they will remain a customer and so on.
Thermal comfort is dependent on environmental factors, such as air temperature, air velocity, relative humidity and the uniformity of conditions, as well as personal factors such as clothing, metabolic heat, acclimatisation, state of health, expectations, and even access to food and drink.
In the 1970s the existing, ‘steady-state’ theory of comfort was challenged by an adaptive comfort theory which suggested that comfort was time dependent, as the occupants of a building would adapt to their environment over time, adjusting clothing, modifying behaviour and so on. This suggested that the occupants of a building might actually accept conditions that would otherwise have been predicted to be unsatisfactory.
It was proposed that an exponentially-weighted outside running mean temperature could account for this time-dependency.
The equation for the exponentially-weighted running mean temperature for time T is:
Trm = (1-α){T(t-1) + αT(t-2) + α²T(t-3)…..}
Were Tn is the temperature at each time interval, and α is a constant between 0 and 1. The temperatures Tn become less significant as time progresses, with the speed of decay depending on the value of the constant α. The lower the value of α, the less significant the weighting of past temperatures.
[edit] Related articles on Designing Buildings Wiki
Featured articles and news
Infrastructure that connect the physical and digital domains.
Harnessing robotics and AI in challenging environments
The key to nuclear decommissioning and fusion engineering.
BSRIA announces Lisa Ashworth as new CEO
Tasked with furthering BSRIA’s impressive growth ambitions.
Public buildings get half a million energy efficiency boost
£557 million to switch to cleaner heating and save on energy.
CIOB launches pre-election manifesto
Outlining potential future policies for the next government.
Grenfell Tower Inquiry announcement
Phase 2 hearings come to a close and the final report due in September.
Progress from Parts L, F and O: A whitepaper, one year on.
A replicated study to understand the opinion of practitioners.
ECA announces new president 2024
Electrical engineer and business leader Stuart Smith.
A distinct type of countryside that should be celebrated.
Should Part O be extended to existing buildings?
EAC brands heatwave adaptation a missed opportunity.
Definition of Statutory in workplace and facilities management
Established by IWFM, BESA, CIBSE and BSRIA.
Tackling the transition from traditional heating systems
59% lack the necessary information and confidence to switch.
The general election and the construction industry
As PM, Rishi Sunak announces July 4 date for an election.
Eco apprenticeships continue help grow green workforce
A year after being recognised at the King's coronation.
Permitted development rights for agricultural buildings
The changes coming into effect as of May 21, 2024.