Adaptive Thermal Comfort
In the past, ‘comfort’ has been given a very simple definition. A temperature of 21°C, plus or minus a degree or two, has been the unquestioned convention adopted for the majority of ‘air conditioned’ buildings. Modern research has shown that people are far more adaptable than the convention supposed and in fact, rigid temperature control will actually cause more problems than it intends to solve.
The Adaptive Comfort model takes this a stage further and recognises that people will adapt to a gradually changing thermal environment, as long as they have the means of adapting, such as by opening a window, or pulling down a blind, or increasing airflow over them or just changing clothing, this all helps to reduce the incidence of dissatisfaction with the internal environment.
Also of significance is the temperature range over which comfort can be achieved if the other related criteria are satisfied. Air temperatures of up to 26ºC, when the external temperature is at 28ºC, can still provide comfort conditions in an office, as long as there is good air movement and the humidity is within the acceptable range.
It is this appreciation of the variable nature of comfort that allows us to explore better ways of achieving control of the internal environment, to provide comfort for more occupants and to significantly reduce energy consumption.
Renewable Technology
Photovoltaic (PV) cells – PV cells convert daylight into electricity.
Solar Thermal Collectors – Solar collectors transfer heat provided by the sun’s energy to either an air or water based heating system.
Biomass hot water generation – Biofuels are organic products such as trees, crops, and animal waste processed to form a carbon based fuel to heat water.
Combined Heat and Power (CHP) – CHP is an engine that simultaneously generates heat and electricity from burning fuel (e.g. natural gas, oil, or biofuels).
Ground and Air Source Heat Pumps (GSHP & ASHP) – Heat pumps are electrically driven refrigerators that operate in reverse.
Ventilation Heat Recovery – Ventilation heat recovery makes use of the heat within exhaust air streams to heat up incoming fresh air.
Low Energy
Increase thermal mass of building facades and structure – Heavier thermal massed buildings can provide up to 10%25 of the cooling energy required to maintain comfortable conditions.
Building Management Systems (BMS) – The system will monitor and control services such as heating, ventilation and air-conditioning (HVAC), ensuring they operate at maximum levels of efficiency by sustaining the optimum balance between environmental conditions, energy usage and operating requirements.
Air permeability of building envelope – to reduce the amount of unwanted, uncontrolled infiltration of cold air in winter which causes discomfort and imposes a considerable demand on the heating system.
Movement and daylight controlled lights – A combination of Natural day light studies and intelligent lighting systems allows the building to react to the levels of daylight and presence of people, therefore reducing energy demand.
Materials
Sustainable materials – Selecting materials from sustainable resources. Materials are assessed in terms of their environmental impact across their life cycle from ‘cradle to grave’, with an emphasis on sourcing locally manufactured materials and services.
Reduction in generated waste – Selecting materials that can be manufactured off site, transported in re-usable packaging, and designing to standard product sizes.
Waste segregation and recycling – This can reduce the cost of tipped waste to a mere 20% of the industry norm by re-engineering processes that produce waste, strategic positioning of waste receptacles and educating the workforce to segregate before disposal.
Solar
Glazing – Increased glazing on the north elevations to maximise natural light into the offices thereby reducing the requirement for artificial light. On the south elevations minimising glazing and using high performance solar glass reduces solar gain, therefore reducing cooling loads.
Bris soleil – Strategic placement of static and moving solar shading on the south and west elevations to minimise solar gain whilst maintaining advantages of natural light.
Building orientation – Reduce the influence of the sun through consideration of building orientation and shape.
Water
Rainwater and grey-water collection – After processing water can be used to supply WC flushing and irrigation needs. This can be further enhanced ground water extraction from a borehole.
Low water use fixtures – Aerated tap and shower fittings reduce the flow rate by 50%25 and more without impacting on performance. Low flush W.C.’s and waterless urinals all combine to drastically reduce water consumption
Water Control Systems –Strategically installed and linked to the BMS to give data on water usage, status information, and leak detection
Sustainable Drainage Systems (SUDS) – A concept that includes long term environmental and social factors in decisions about drainage taking account the quantity and quality of runoff to minimise flooding, pollution or damage to the environment.
