While temperatures in Palo Alto often allow windows to be opened, a heat-recovery ventilator (HRC) provides fresh air when temperatures outside are extreme.  Photo 3 of 8 in Project Green Home by Arkin Tilt Architects

Project Green Home

3 of 8

While temperatures in Palo Alto often allow windows to be opened, a heat-recovery ventilator (HRC) provides fresh air when temperatures outside are extreme.