Supermarket Ventilation System Basics
video description
Most of the heating comes from the refrigeration racks, we call them heat reclaims, some are piped in the ducts while some in the rtus directly, AAON for example has units designed to accommodate a reclaim coil. Theres either a heat exchanger at the rack with a glycol loop or sometimes refrigerant is sent directly to the reclaim coils before going to the condenser. The back stores and the entrance have reclaim fan coils to heat. Most rtus and air handlers hold a secondary heat source to compensate for very cold days.
The big interior air handlers have a condensing unit on the roof to feed the evap coil, in rare occasions Ive seen a small dedicated parallel rack just for the air handlers. The amount of fresh air brought in depends on a lot of factors, sometimes if theres a lot of exhaust fans well use specialized rtus like AAONS to compensate for the loss, but in other cases, with kitchens for example, theres a dedicated make up air. In winter we definitely let more air through since its already cooled and the RH is more easily controllable.
One of our main goal with the ventilation in a supermarket is to dehumidify, maintaining a low RH alleviates many problems on the refrigeration side. In my area, we mostly worry about that in summer. Oftentimes the air will be passed through the evaporator coil which removes latent heat, then since that air is cold, we heat it with the reclaim coil to make it expand and lower the RH. It might sound energy inefficient but the difference that it makes to the refrigeration side outweigh that cost.
Its probably different in other countries but this is what Ive seen so far in my career.
Date: 2023-11-17
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Comments and reviews: 3
Andrew
That dirty used air doesn't leave the air system, it goes back through the return air system passes through the filter and back to the space. What you're showing is a dedicated outdoor air system with an exhaust fan. Which for super markets, is not needed. Also, why pay the cost to condition the outside air from 80, 90, or 100F temp, to 55 - 60 F only just to through that air outside? You pull that now 75-85 deg air back through the system so it doesn't have as great or a delta.
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That dirty used air doesn't leave the air system, it goes back through the return air system passes through the filter and back to the space. What you're showing is a dedicated outdoor air system with an exhaust fan. Which for super markets, is not needed. Also, why pay the cost to condition the outside air from 80, 90, or 100F temp, to 55 - 60 F only just to through that air outside? You pull that now 75-85 deg air back through the system so it doesn't have as great or a delta.
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meberg500
I don't understand why the title mentions supermarkets. All the same things apply at any big box retail store and most office buildings. The HVAC engineer in me wonders if the condenser coils for the refrigerated/frozen section could be used as a heat/reheat source in an air handling unit.
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I don't understand why the title mentions supermarkets. All the same things apply at any big box retail store and most office buildings. The HVAC engineer in me wonders if the condenser coils for the refrigerated/frozen section could be used as a heat/reheat source in an air handling unit.
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Wesley
I often look up at ventilation for air pollution can i pull my mask down im also interested in the changing of filters for PM 2. 5 and thank you for the information.
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I often look up at ventilation for air pollution can i pull my mask down im also interested in the changing of filters for PM 2. 5 and thank you for the information.
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