Economizing and Demand Control Ventilation typically provide three times more free cooling than a basic economizer, and much greater comfort for guests and occupants.
Comparative enthalpy economy from 75F uses real-time outside enthalpy data and compares it with real-time indoor enthalpy data to lower energy costs and improve efficiency through free cooling. Not only does the system compare the two enthalpy values, it also calculates the final enthalpy of supply air when heated up to indoor levels using psychrometric charts to ensure the resulting air meets a desired target. The result is typically three times more free cooling than a basic economizer and much better comfort for guests and occupants.
Most basic economizers on the market today are typically set to only let in outside air when it is 55°F and lower. During winter months, this cold air can cause occupant complaints.
Outside Air Optimization from 75F continuously measures the temperature and humidity in occupied spaces and accurately calculates loads to determine what the best supply air temperature should be. During free cooling periods, 75F will partially open the outside air damper to achieve a comfortable and optimal mixed air temperature.
The 75F Outside Air Optimization kit includes a CO2 sensor in the return duct of the air handler to measure the average indoor air quality of the building’s envelope. When occupancy is high, 75F will modulate the outside air damper to ventilate with fresh air until healthy indoor air quality is achieved.
Other 75F IAQ sensors, such as CO and NO2 sensors, can be added to this sequence for spaces like parking garages or other applications. The 75F outside air sequence includes a control point to activate an exhaust fan based on how much outside air is entering the envelope.
75F uses CO2 levels to determine the amount of outside air that should be brought into a space to maintain an optimal indoor air quality.
The system will automatically and incrementally open the outside air damper calculated based on either the return air CO2, or individual spaces using a Trim and Respond system. This applies to both heating and cooling in 'Occupied Mode'.
Economizers use cold outside air to provide free cooling in a space. Outdoor Air Economizing from 75F uses forecasts and temperature data to predictively determine when outside air is suitable for free cooling. When outside air temperature and humidity is not sufficient to completely cool zones or rooms, then the 75F system uses this air – instead of return air – as a pre-feed to mechanical cooling, thereby saving you energy.
Increase efficiency with the ability to manage your entire system from our suite of web and mobile apps, 75F® Facilisight®. Not only can you make scheduling changes remotely, you can manage the scheduling of hundreds of buildings and monitor them on a single pane of glass wherever you are!