Open Air Interior Seating Affecting Existing AC System? 1

[SoFloJoe]

Hi All,

I have a commercial restaurant client that wants to open up their interior space with folding windows. The restaurant faces the ocean in FL so they want to have the outdoor feel for the customers. But currently the space is interior and has several AC vents to this space as it is the largest space.

I have already advised the client that the space would need to be closed from the other spaces as to isolate the area. And would likely need to install automatic dampers to close the vents when the space is open. And possibly need to program the AC unit to slow down the motor speed as to not freeze the other areas. I am not sure if this is easy or requires a whole new AC system.

Since we are in FL we have condensation to consider as well.

I was wondering if I am correct in my considerations and what else I maybe over looking?

Anybody have experience with this scenario?

Thank you,

 

[EnergyProfessional]

Inquire about if they plan on specific operating hours for it to be open. If in summer during the day, that indoor space will be unbearable and they may want to keep AC for that (even if wasteful). If they only want to open at (cooler) night, it will be better.

Prepare them no matter what you do to AC, it will feel warmer/more humid. Manage expectations. the added load will depend on airflow and a warm breeze blowing may make things worse, a cooler breeze will make it better. See above, for what times of day and year they want that.

If you want to add dampers, also add dampers to return from that semi-open space.

 

[SoFloJoe]

Thank you EnergyProfessional

I believe they plan to keep it open (as long as it is bearable). I was thinking of even separating the zones.

My worry about having the system running while doors are open will be the condensation and potential of mold growth. In my opinion it should be off but the owner can install large ceiling fans.

Thanks again for the input!

 

[nuuvox000]

I agree, the A/C should be off if they want the windows open; use fans instead. Sometimes you can damper off small spaces on an existing system but if this is the largest space then you'll have to see what kind of equipment they have. I really doubt their existing equipment can function at less than half of the original design airflow.

 

[SoFloJoe]

Thank you. For now the owner is not pursuing opening the space.

But the solution would be to install separate units for the separate spaces.

 

[IRstuff]

Is there no concern that in Florida, the humidity is high enough that the condensation might freeze up on the coils?

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[MedicineEng]

We had a similar situation a couple of years ago in a swimming pool support restaurant/bar, but it was a small space (around 40 people) and was supplied by an AHU with VAVs
Operator wanted to open the folding doors to the restaurant while still keeping the AC on. Despite our remarks, he insisted to move forward with that idea and obviously didn't work so well in a semi tropical environment with condensation dripping on client's plates...

We ended up installing proximity switches in the folding doors and whenever they decided to open it, the AHU system would automatically increase the supply air temperature just a couple of degrees below outdoor conditions.
This addressed most of the condensation and gave the feeling of walking into a slightly cooler space when you were coming from the pool area which was enough to keep client's happy.

 

[SoFloJoe]

Thank you MedicineEng

I have not heard back from the client nor did he actually pull a permit. He started doing his work on his own.

That does make sense. Assuming the sensors are accurate and switches work correctly.