Effect of Building Pressurization with Heat Recovery Device

[Buildtech2]

I need a second opinion in my ongoing project as follows.
We have considered heat recovery device in the current high and low bay warehouses by which most of the supplied fresh air will be exhausted via heat recovery device but recently our client informed us that the low bay warehouse will be provided with 3 big doors which will be kept open for loading the trucks with cartoons from warehouse. If we exhaust most of the supplied fresh air while keeping the doors open, Its highly possible that warehouses will be negatively pressurized and subjected to huge infiltration, though we can provide air curtains but they are not very effective to deal with infiltration.

So I am thinking to exclude heat recovery device so that we can have enough fresh air in the warehouse to avoid infiltration but we will provide some wall mounted exhaust fans to avoid over pressurization in the event when doors are closed.

 

[317069]

Can you explain your question with more information such as air flow rates, what did you mean by most fresh air, huge infiltration from where?
also, with HRV the fresh air is coming through the HRV itself and if you remove it then how would you provide fresh air?

 

[DRWeig]

I have installed door monitors before in similar situations. Pump up your fresh air flow when door is open to maintain positive pressure, and reduce when door is closed. With three doors, you may have a complicated system but in my experience the open truck doors will do as you say and allow lots of infiltration. Good truck seals can help.

Best to you,

Goober Dave

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[dbill74]

No need to ditch the heat recovery units. As part of the exhaust/fresh air systems it's up to you as the designer to determine the amount of exhaust/outside air they move. If you're concerned about infiltration when the loading doors are open, set the ratio of OA to EA a little higher or add supplemental OA units to energize when the loading doors are open.

 

[Drazen]

supply air distributors should be placed near doors, exhaust on the opposite side.

 

[Buildtech2]

Thanks everybody.

I do like the suggestion of using supplemental outside air unit to energize when the loading doors are open.Please see attached file for cooling capacities and air quantities.

 

[Compositepro]

What difference is there between air infiltration from open doors or from an outside air blower? The only difference is if you condition the outside air. Just use air curtains at doorways to minimize infiltration.