Encofrado perdido Iglu

21 Energy recovery with Iglù® Natural ventilation has advantages with regard to the health of the environment, but directs a quantity of heated air outside of the buildings from the loss of building and ground heat (see diagram below). Growing sensibility towards the more sustainable use of resources has led the Daliform Group to study the thermodynamic effects of the under-floor cavity, with particular focus on the recovery of the geothermal heat it contains, which is generally wasted. The system, which involves the use of increasingly common technological systems such as heat exchangers and heat pumps/ compact aggregate pumps, makes it possible to signifi cantly improve the performance of Casaclima certified buildings. In fact, with current law no. 192/2005 energy consumption for heating is approx. 100 kWh/m2 per year; when respecting the standards of CasaClima B consumption is less than 50 kWh/m2 per year, and the use of an energy recovery system makes it possible to reduce this consumption by at least 2.7%; in a CasaClima A certifi ed home (< 30 kWh/m2 per year) this would permit an additional 4.4% savings; fi nally, in a CasaClima Oro certifi ed home (< 10 kWh/m2 per year) this savings increases to 11.3%. In this case, a "package" was created consisting of the following, from the bottom upward: - Gravel cm 10 - Iglù® cm 27 + Beton Up - 15 cm slab - 20 cm insulation (EPS) - 5 cm screed The transmittancy of this package was calculated according to the regulations of EN ISO 13370. The adopted solution foresees the creation not of a traditional under-fl oor cavity, but a slab that acts statically like a double fl oor. This is to avoid the lean concrete below the Iglù® formworks, which increases the thermal capacity of the (wet) ground, thereby recovering the heat. An alternative solution foresees the use of Iso Iglù® directly above the under-floor cavity; in this case the following “package” is created: - Gravel 10 cm - Iglù® 27 cm - Iso Iglù® 10 cm - 15 cm slab The advantage in this case is that the concrete can be poured with one casting, creating at the same time the foundation beams and the slab, avoiding the use of lean concrete and screed. The last example, which is only to be applied in an area without Radon gas, foresees an outdoor pit with a condensation exhaust fan that is able to dehumidify the air in the under-fl oor cavity without mixing it with outdoor air. In this way, an under-fl oor cavity is obtained that performs like a closed cavity, better insulating the building from the ground. External air Outlet internal air Dispersion from pavement Geothermal heat Air replacement (Mechanical ventilation system) Heating system (heat pump) Heat exchanger Inlet internal air External air inlet Humid air and radon gas outlet Heat exchanger Preheating in the under-floor cavity www.baygar.com