latent load

[317069]

Hello
Let us say we are designing an HVAC project.
the design occupation load as per local code was for example 50 person
we have calculated load and selected equipments based on this data and the project has been constructed.
But in the actual situation the tenant of this building has only 20 employees, so what the situation would be.?
I mean the selected equipment would be oversized for the latent portion of the load, I know it is ok if the equipment was oversized for latent load but how much the percentage would be ok 5%, 10% or more.
does that result to reduce the relative humidity severly?
Can we solve this problem by using fresh air through economizer or HRV which replace the space air periodically?
thanks

 

[imok2]

You may not have a problem if you just raise the room temperature because the The RH comfort zone for most people falls between 25% and 60%, depending upon the air temperature. Most people are happiest with their environment when temperatures are between 68º and 78ºF, given the correct activity level, clothing, relative humidity and air velocity. But there’s one other factor to be considered and that is Radiant Surface Temperature
Even if all the other variables are correct, the surface temperatures of a room can dominate the comfort equation, still leaving the occupant uncomfortable. During winter, cold walls, floors or windows seem to suck the heat right out of a room – as well as the body. In Summer, unshaded windows or poorly-insulated walls can turn any room into a virtual oven despite lots of air-conditioning or airflow.

 

[IRstuff]

The bottom line is that if the occupants start complaining about the temperature being too cold, they'll change the setting of the thermostat to compensate.

TTFN

FAQ731-376

 

[ChrisConley]

I've never heard of people complaining a space was to dry in the cooling season. And I've heard people complain about everything...

 

[mauricestoker]

The building would probably not be occupied at all times, and during the summer it could be raining one week and bone dry and hot the next week. Unless you are designing for something that is dew point sensitive, like a chilled beam, having excess latent cooling capacity should not be an issue. Unless you can control the weather, it will happen.

 

[marcoh]

Its not an issue.

If the population decreases, the space cooling demand decreases, and the supply air temperature is reset up, resulting in less dehumidification.

This is typical of most system where design loads are rarely achieved.

 

[317069]

Thank you for your replies