The project involved several construction-industry partners (Trécobat, Atlantic, Velux, K-Line, Delta Dore, and Vicat). Liten and the CEA Tech team in PACA region helped design and build the experimental home, which leverages a concrete core offering excellent thermal inertia and a wood structure. The house, built at the CEA Tech site in Cadarache, in the south of France, has been up and running for several months now, and the initial results are in.

Liten came up with a novel cooling system to keep the home from heating up too much during the day. A sliding window opens automatically onto an interior patio at night, allowing cool air to circulate throughout the house, cooling the concrete core. The air then escapes through a skylight, also operated automatically.

Initial tests demonstrated that the natural circulation of cool air was able to maintain comfortable indoor temperatures (never exceeding 25 °C during the day). Other approaches—like automatically closing shutters during the day to keep the sun out—were also tested. “We were able to show that the effects of cool air circulating at night were far greater than keeping the sun out during the day on this house, which was designed with a roof overhang,” said CEA Research Director Etienne Wurtz.

The next step, to be tested this winter, will be to investigate ways to use the crawlspace under the house to remove “stale” (and hot) air from the home and recover the heat from that air using a heat pump.