I heard a rumor that OMA used the structural steel tubes as HVAC ducts, but I can't find any info that confirms/denies this. has anyone heard anything about this one way or another? has anyone seen any documentation on this?
from a design perspective it seems like it would be super-difficult to always have required member sizes and required duct sizes be completely in concert with each other. seems like this could create a potential for inefficiency in structural and hvac systems.
other possible problems i can think of are...
-potential for condensation inside the structural members which could rust them internally and eventually compromise the structure.
-necessity of insulating "ducts" to prevent above problem means structural members probably end up being concealed behind other finishes anyway.
-hard to keep insulation continuous/uncompromised at structural connection points.
-difficult or impossible to inspect/clean inside "ducts."
-difficult to reconfigure spaces or change building use in future.
Well the SPL definitely needs the heating part of that in the winter... I would argue that it could probably do without AC (yes, despite all those windows- it's cold here!)
We've used displacement systems on a few projects with no issues - it's hugely advantageous from an energy standpoint in cooling dominated buildings as you only need to condition the occupied zone. Condensation is a non-issue except in extremely high humidity environments where building is allowed to swing very warm during off hours - the supply air is typically not less than 16 or 17C. Coordination is no more complicated than with an standard exposed forced air system - the only drawback is with penetrations when you have a rated floor condition.
Perhaps what you are thinking of is a "chilled beam" system? That is a bit of a misnomer as the structural members are not actually chilled, rather there is essentially a radiant panel at the ceiling that receives circulated chilled water. Fresh air for ventilation is supplied from a separate (much smaller than usual) ducted system.
not sure if france is pefromance based with the fire regulations, but i thought america was prescriptive? so you don't get to be creative kinda thing...?
here is performance based, so if you care to spend the money all you have to do is prove your system meets the intent of the regulations...usually only starchitecture goes this route...but is not uncommon.
no idea about seattle library but i would be interested in finding out how it works if they did do that. there would be so many technical reasons for not doing it to overcome....
this is usually difficult to have operable windows for a major library, not so much for the thermal constraints, but for moisture/humidity control. Books, and particularly rare books needs fairly controlled or at least stable, non-fluctuating humidity so that various forms of mold and decay do not get started on books that might not be viewed or checked out for years at a time. unless there is a clear separation of controlled versus non-controlled material, then it is easier just to have a sealed building and work at keeping energy usage down.
displacement system, particularly in large-volume spaces, is also an advantage in terms of noise. with forced air systems, not only does the air have to be chilled much lower than in a displacement system (maybe 12ºC vs 17ºC), but the velocity of air coming needs to be quite high in order to be forced downwards, create a mixing of hot and cold air, and this is a quite audible hiss. with displacement, the air comes out at low velocity and uses natural convection to move upwards, displacing the hotter air.
HVAC in the seattle library
I heard a rumor that OMA used the structural steel tubes as HVAC ducts, but I can't find any info that confirms/denies this. has anyone heard anything about this one way or another? has anyone seen any documentation on this?
i know it utilizes displacement ventilation. but that's all i can remember right now...
sounds like a bad idea
why?
lots of reasons i can see...
from a design perspective it seems like it would be super-difficult to always have required member sizes and required duct sizes be completely in concert with each other. seems like this could create a potential for inefficiency in structural and hvac systems.
other possible problems i can think of are...
-potential for condensation inside the structural members which could rust them internally and eventually compromise the structure.
-necessity of insulating "ducts" to prevent above problem means structural members probably end up being concealed behind other finishes anyway.
-hard to keep insulation continuous/uncompromised at structural connection points.
-difficult or impossible to inspect/clean inside "ducts."
-difficult to reconfigure spaces or change building use in future.
do we always need hvac? at least in the summer, can't we just open the windows? i hate buildings that don't have operable windows.
Well the SPL definitely needs the heating part of that in the winter... I would argue that it could probably do without AC (yes, despite all those windows- it's cold here!)
largest homeless shelter in Seattle...
...Only because politicians and taxpayers don't care enough to adequate fund measures to support the homeless.
apparently they have problems at the libraray with overloading on the plumbing systems becuse of the heavy bathroom use in the morning
PRAXIS had a feature recently that had some info on the SPL facade. Maybe have a look, see if it mentions anything about HVAC.
It's the blue-ish/turquoise colored issue.
We've used displacement systems on a few projects with no issues - it's hugely advantageous from an energy standpoint in cooling dominated buildings as you only need to condition the occupied zone. Condensation is a non-issue except in extremely high humidity environments where building is allowed to swing very warm during off hours - the supply air is typically not less than 16 or 17C. Coordination is no more complicated than with an standard exposed forced air system - the only drawback is with penetrations when you have a rated floor condition.
Perhaps what you are thinking of is a "chilled beam" system? That is a bit of a misnomer as the structural members are not actually chilled, rather there is essentially a radiant panel at the ceiling that receives circulated chilled water. Fresh air for ventilation is supplied from a separate (much smaller than usual) ducted system.
on a side note, the columns at the Pompideau (sp?) Center in Paris are filled with water for fireproofing reasons
That's something to remember for the next time I talk with a code consultant.
not sure if france is pefromance based with the fire regulations, but i thought america was prescriptive? so you don't get to be creative kinda thing...?
here is performance based, so if you care to spend the money all you have to do is prove your system meets the intent of the regulations...usually only starchitecture goes this route...but is not uncommon.
no idea about seattle library but i would be interested in finding out how it works if they did do that. there would be so many technical reasons for not doing it to overcome....
re: operable windows -
this is usually difficult to have operable windows for a major library, not so much for the thermal constraints, but for moisture/humidity control. Books, and particularly rare books needs fairly controlled or at least stable, non-fluctuating humidity so that various forms of mold and decay do not get started on books that might not be viewed or checked out for years at a time. unless there is a clear separation of controlled versus non-controlled material, then it is easier just to have a sealed building and work at keeping energy usage down.
displacement system, particularly in large-volume spaces, is also an advantage in terms of noise. with forced air systems, not only does the air have to be chilled much lower than in a displacement system (maybe 12ºC vs 17ºC), but the velocity of air coming needs to be quite high in order to be forced downwards, create a mixing of hot and cold air, and this is a quite audible hiss. with displacement, the air comes out at low velocity and uses natural convection to move upwards, displacing the hotter air.
an open window does not equal mold...
if your outdoor temperature/humidity is within your desired band open the window...when its not run your internal climate controls.
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