Indoor air quality and maximum outdoor rate were determinedusing Standard 62.1-2004.
To achieve high indoor airquality at all times in conjunction with energy efficiency, CO2sensors modulate the fresh outdoor airflow rate to always getthe correct amount while keeping the associated load low.
Theventilation system is a dedicated outdoor air system (DOAS),ensuring that every zone is getting the right amount of fresh air.
As stated by Standard 62.1-2007, when using CO2 sensors, the design outdoor air intake flow (Vot) may be reset, so no minimumairflow is needed when the CO2 concentration is below the limit.Special care also was taken to get high ventilation effectiveness in accordance with Standard 62.1-2007 by optimizing the type,number and size of each diffuser.
That special attention led to an Ev higher than 0.9 in the entire building.Unlike the five other Sobey’s refrigerated warehouses in Quebec’s province, this warehouse has an energy recovery unit and a fresh air supply control led by CO2 sensors.
The design outdoor airflow rate of the refrigerated warehouse was calculated using the rationale for minimum physiological requirements for respiration air based on CO2 concentration and other contaminants in Appendix C of Standard 62.1-2004. The use of this calculation method decreased the amount of fresh air needed from 7,200 cfm (3398 L/s) to 1,800 cfm (849 L/s).
This is a significant energy saving and reduction in size of equipment. The real supply airflow rate also is lower since it is controlled by the CO2 sensor while providing enough outdoor air.
There have been no complaints from the occupants about comfort and the building’s improvements have created a general feeling of pride among employees. This feeling can be noted by the care and respect they have towards the building.
To get the optimal thermal comfort of 60% thermal radiation and 40% thermal convection (2007 ASHRAE Handbook—HVAC pplications) heating is provided by radiant floor.
Control setpoints for temperature and relative humidity are always within the acceptable range that provides thermal comfort according to the Standard 55-2004 calculation method, which includes metabolic rate, clothing insulation, air temperature, radiant temperature, air speed and humidity.
The ventilated warehouse also contributes to increasing the environment quality of warehouse workers as compared to a nonventilated one. Refrigerated warehouses usually don’t have ventilation.
Startup commissioning has been done by the client assisted by the engineer, and only minor condensation problems on the ERV have been noted. In the process of LEED accreditation, a monitoring plan based on International Performance Measurement and Verification Protocol, Vol. III, has been developed.
The scope of this monitoring plan is to compare the performance of the energy-efficiency measures with their initial predictions. This plan is under application, but no conclusions are
available yet.