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Discussion Starter · #1 · (Edited)
To all HVAC commercial specialist out there, we've been preparing for 12 year renovation of 5 story hotel in West Virginia and the owner wants us to include in our bid eliminating negative air pressure in the building.
It's not our expertise but thought I will post out here to get some feedback from all of the pros.

Let me start here from what I know,

Engineer tested the building 2 years ago. I attached 2 pages of negative air pressure report.
The building was constructed 30 years ago and there is no original mechanical plans available.
To my knowledge, there is a central roof fan for all the exhausts in the guest bathrooms which sucks the air out,
There is a central furnace with exhausts in the corridors
There is appx 20 rooms per floor
Lobby and breakfast area has it's own roof fans

We do have an existing chase in the storage room on every floor ( storage room is located at the end of the corridor on each floor) that's covered with plywood on the roof. Chase size is 1.5' x 1.5' x 12' on the 5th Floor and it goes down to 1'x1'x8' to the 2nd Floor. 1st Floor has only vent louver at the ceiling. 5th Floor has 12' ceiling height, the other floors are 8' high.

All the windows are double insulated glass that obviously don't open.
To my understanding there is no make up air coming into the building except for on / off AC units in the Guest Rooms and opening / closing exterior doors

I've been talking to few design build mechanical contractors and got one quote so far without him coming and even looking at the building ( looks like that state didn't feel much recession??).

That mechanical contractor that haven't seen the property suggested two options,

Option 1 Energy recovery unit and heat pump

To install one energy recovery unit to collect exhaust from the guest bathrooms per floor, these would pre treat the outside air before going into a heat pump to discharge make up air into each floor
Fabricate and install new ductwork to run down the hallway to the restrooms
New exhaust registers
Controls for the system
Line sets to outdoor unit
Penetrations for the intake and exhaust louvers

Option 2 Two roof mounted make up air units

To install two roof mounted gas/electric make up air units
To Cut floor for ductwork to pass through floors ( he suggested that existing non-used chase is too small)
To fabricate and install ductwork to distribute make up air through building
Fire dampers at floor penetrations
Controls
Crane to set units

If there is any HVAC experts who feel confident in providing a solution to the problem and would like to bid on that project please PM me,
If you could provide some more feedback or solutions to the problem I would really appreciate it. We've done few projects for the same owner and never had to deal with the HVAC issue before so excuse my lack of knowledge and advice me if you need any more information.

Thanks,

Josh
 

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You'll need an engineer to come and see the building.

The 1.5X1.5 chase isn't big enough to carry 20% of the fresh air you'll need.
 

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Define YOUR needs

To all HVAC commercial specialist out there, we've been preparing for 12 year renovation of 5 story hotel in West Virginia and the owner wants us to include in our bid eliminating negative air pressure in the building.
It's not our expertise but thought I will post out here to get some feedback from all of the pros.

Let me start here from what I know,

Engineer tested the building 2 years ago. I attached 2 pages of negative air pressure report.

To my knowledge, there is a central roof fan for all the exhausts in the guest bathrooms which sucks the air out,

There is appx 20 rooms per floor
Lobby and breakfast area has it's own roof fans

Option 1 Energy recovery unit and heat pump

Option 2 Two roof mounted make up air units

If there is any HVAC experts who feel confident in providing a solution to the problem and would like to bid on that project please PM me,

If you could provide some more feedback or solutions to the problem I would really appreciate it. We've done few projects for the same owner and never had to deal with the HVAC issue before so excuse my lack of knowledge and advice me if you need any more information.

Thanks,

Josh
JO$H,

22,000 CFM and Counting
for ~ 100 room$.

You haven't $tated if this is 100% residential or $ome sort of Mixed U$e.
Providing plan$ ( $quare Feet and occupancy) to a local W.VA. Professional MECHANICAL Engineer is the

FIRST $TEP in addressing the Owner's $pecification of "eliminate negative pre$$ure".

:clap:
STEP 2 - USE MUST BE DEFINED.


> 200 CFM per room seems quite Extreme.
:rolleyes:
JUST Waiting for the $ticker $hock$ in addressing that amount of outside air.
Minimize Out$ide Air AND maintain amount to match NEEDS & use recovery units -
_______ $$$, $$$ ______ P L A N ! !!! !!!!!
 

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Discussion Starter · #4 ·
Dan,

It's a hotel. To be exact 87 rooms, average room size 12.5'x27' (including guest bath). The rest of space corridors, stairways, 2 elevators, 5 storage rooms, few laundry rooms, housekeeping room, pantry (no full service kitchen), breakfast area, lobby area and few other standard hotel common area rooms,
I've talked to mechanical engineer and he checked the neg. press. report and refereed me to the local mechanical contractor who provided me with those two options. I remember he mentioned that we got little over 100 cfm per guest room.

Option 2 is definitely no go. It will run the cost too high and the owner looking for most affordable option and I know he won't go for it.
I just feel like sometimes contractors will tell you the options that suit them the best, but not always the most affordable solution.

Thanks Dan. As I said, I'm amateur in that subject and will be providing more info as requested. If it was for me I would just cut out 2'x2' hole at the corridors on each floor and pump the air in :) j/k,

JOSH
 

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You need to go to a different mechanical engineer then. A good one should go out to the site and check it out, and design this for you. For a fee of course. The plans are going to need a engineers stamp on it.
 
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