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In an ideal world every occupied building in Ireland would be energy upgraded to the highest standard, tapping into numerous benefits for the building occupant, the construction industry and society as a whole. Construct Ireland is calling for the introduction of pay as you save, a repayment model which offers the potential of making significant energy upgrade investments achievable in the vast majority of Irish buildings, as Jeff Colley reveals.
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The Dept. of Agriculture’s new district veterinary office in Drumshanbo, Leitrim
In other areas of the first floor, a passive stack ventilation system uses wind as a source of natural ventilation. Fresh air is carried passively from wind cowls on the roof through ducts to the floor below. The cowls capture the prevailing wind regardless of its direction, and turn it down through a 90 degree angle before delivering it to the space below. At the same time, the difference between the indoor and outdoor temperatures creates a pressure gradient that causes stale warm air to rise up and out of the building.
Dampers in the cowls control the volume of air coming in, and can be automated to open at specific temperatures, CO2 concentrations, or humidity levels. If the temperature drops too low, the dampers close to prevent overcooling. On summer nights they open fully to ensure indoor air is fresh each morning. The passive stack system has no moving parts and thus requires little maintenance, and it can be used to ventilate multiple floors of a building.
An iroko brise soleil along the southern and western facades also helps to passively cool the building. Essentially a series of outdoor timber blinds running horizontally along glazed sections, the brise soleil shades the interior to prevent overheating and glare. To avoid interrupting general eye level, it doesn't come down below a height of 1.8m. "It's like a Venetian blind and is set at an optimum angle of 60 degrees," Sean Moylan says.
The entrance courtyard forms an obvious focal point of the building
A mechanical air handling system in the floor also helps cool the building. If the temperature inside at night is sufficiently warmer than outdoors, fans kick in and blow fresh air under the raised access floor and up into the space above. The cool air makes contact with the exposed concrete slab inside, cooling it down. OPW mechanical and electrical engineer Frank Reilly says the system's electricity consumption is low. Downstairs two meeting rooms are cooled by local air conditioning units, and other rooms are manually ventilated with openable windows.
Floor-to-ceiling windows allow generous sunlight into the building so there's little need for electrical lighting. The artificial lighting system – consisting of T5 flourescent tubes – is automated so lights only come on when needed. "They work on the basis of occupancy,” Frank Reilly says. “If there's nobody there the lights don't come on in the space, and when the daylight exceeds 500 lux the lights start dimming.” The lux is a unit that measures the intensity of light.
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Issue 1, Vol 5 Out Now
The new look issue of Construct Ireland is available now. Click here to subscribe online and have the latest issue delivered to your doorstep
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