Method and apparatus for controlling ventilation systems

A ventilator comprising:

• a ventilator enclosure comprising a supply inlet receiving a supply airflow from an exterior of a building, a supply outlet discharging the supply airflow to the interior of the building, an exhaust inlet receiving an exhaust airflow from an interior of the building, and an exhaust outlet discharging the exhaust airflow to the exterior of the building,
• a first direct current (DC) fan drawing supply air through the supply inlet and discharging supply air through the supply outlet, said first DC fan producing a supply airflow through the ventilator enclosure;
• a second DC fan drawing return air through the exhaust inlet and discharging the exhaust air from the exterior of the building thereby creating the exhaust airflow through the ventilator enclosure;
• a first temperature sensor, proximate to the supply inlet, determining a first temperature of supply air entering the ventilator enclosure;
• a second temperature sensor, proximate to the supply outlet, measuring a second temperature of supply air exiting the ventilator enclosure;
• a third temperature sensor, proximate to the exhaust outlet, measuring a third temperature of return air exiting the ventilator enclosure;
• and
• a controller controlling the fans and regulating the supply airflow and the exhaust airflow, said controller comprising receiver receiving a first input from the first temperature sensor, a second input from the second temperature sensor, and a third input from a third temperature sensor, means for calculating a thermal efficiency for each of the supply airflow and the exhaust airflow for balancing the supply airflow and the exhaust airflow and drivers for independently adjusting a first fan speed for the first DC fan and a second fan speed for the second DC fan in response to each of said first, second and third inputs, thereby optimizing the supply airflow and the exhaust airflow by balancing the supply airflow and the exhaust airflow,
• wherein the supply airflow and the exhaust airflow are balanced if the thermal efficiency of the supply airflow and the thermal efficiency of the exhaust airflow are equal to pre-determined efficiencies.