Demand control ventilation sensor failure

A method of controlling ventilation of an environment, the method comprising the steps of:

• monitoring an indication of occupancy of the environment and storing one or more historical occupancy levels;
• modifying a relative amount of fresh air provided to the environment in response to the indication of occupancy;
• and
• providing an amount of fresh air to the environment if the indication of occupancy is deemed to be erroneous, wherein the amount of fresh air is dependent on the one or more historical occupancy levels.

A method of adjusting a damper configured to ventilate an environment, the method comprising the steps of:

• monitoring a reading from a carbon dioxide sensor to identify an occupancy level of the environment, and to store one or more historical occupancy levels;
• adjusting the damper to a first damper position that is dependent, at least in part, on the reading of the carbon dioxide sensor;
• and
• adjusting the damper to a second damper position upon determining an erroneous reading from the carbon dioxide sensor, wherein the second damper position is different from the first damper position, and is dependent on one or more of the historical occupancy levels.

A controller configured to control ventilation of an environment, the controller configured to:

• monitor an indication of occupancy over time and storing one or more historical occupancy levels;
• modify a relative amount of fresh air provided to the environment in response to the indication of occupancy;
• determine if the indication of occupancy is erroneous;
• and
• provide an amount of fresh air to the environment if the indication of occupancy is determined to be erroneous, wherein the amount of fresh air is dependent on the one or more historical occupancy levels.

A method of controlling ventilation of an environment, the method comprising the steps of:

• monitoring an output of an occupancy indicator of the environment;
• providing a first amount of fresh air to the environment if the occupancy indicator is deemed to be providing an output that is erroneous, the output being erroneous if outside of a valid range, wherein the valid range is dependent upon a time of a day and/or a day of a week;
• and
• providing a second amount of fresh air to the environment if the occupancy indicator is deemed to be providing an output that is valid, the output being valid if inside of the valid range, wherein the second amount of fresh air is different from the first amount of fresh air and is dependent, at least in part, on the valid output of the occupancy indicator.

A method of controlling ventilation of an environment, the method comprising the steps of:

• monitoring an output of an occupancy indicator of the environment;
• providing a first amount of fresh air to the environment if the occupancy indicator is deemed to be providing an output that is erroneous, the output being erroneous if outside of a valid range;
• providing a second amount of fresh air to the environment if the occupancy indicator is deemed to be providing an output that is valid, the output being valid if inside of the valid range, wherein the second amount of fresh air is different from the first amount of fresh air and is dependent, at least in part, on the valid output of the occupancy indicator;
• and
• wherein the first amount of fresh air is dependent, at least in part, on the valid output of the occupancy indicator just before the occupancy indicator was deemed to be providing an output that is erroneous.