Sensible and Latent Capacity

[Husky250]

Hello All,

I have a question I hope you guys can help me with. If you have performed a load calculation, you will know the sensible and latent capacity needed for the conditioned space.

When you are selecting equipment, is it equally as important to know the sensible and latent capacity the equipment will produce? I have always been told it is the manufactures job to provided documentation what the Sensible and Latent capacities are at design conditions. This documentation will give the engineer enough information to make the proper selection. Is my assumption correct?

I had another design engineer argue his point on this subject. He states if you select and size your equipment based on total capacity....that is all that is needed. I'm not the best on load calculations....so I wanted to get some feedback from you guys.

I have had some calls on mold and bacteria into the ductless mini-split Indoor coils. For the most part....the systems with this issue are non-Inverter systems....and located on the coast close to beaches...So my next question is, where is the load calculation? How was the equipment selection process done? Most of all, I can only find a few manufactures showing sensible and latent capacity at design conditions. So I thought maybe I was wrong..

Can you guys please give me some advice here?

Cheers,
Husky

[BritCit_Juve]

The sensible and latent loads are both important but which is most important depends on the application.
In most cases the equipment is being installed to provide comfort cooling for people and in this case the total cooling would probably be used.
If however the room is an office, IT suite or generally contains a high sensible load then you would size the unit for the sensible load.
Most manufacturers these days provide the total and sensible duties and if they don't then you would be safest assuming those units are ONLY for cooling occupants and NOT suited to equipment rooms.
Mold and Bacteria are plain down to lack of maintenance. if the units are near the beach then humidity will be high resulting in a large qty of moisture removal which will contain spores and bacteria. If the unit is then turned off for 6 months in a generally warm environment and without cleaning then they will multiply.
Brit

[botrous]

It's the manufacturer duty to tell the total capacity and the sensible capacity.... in the other case and if you need to estimate it use a coil design software like USAcoil, enter the dimensions of the evaporator, the air flow, the working conditions and you will get the estimated data with a good precision.

Respects and regards

[Husky250]

It's the manufacturer duty to tell the total capacity and the sensible capacity.... in the other case and if you need to estimate it use a coil design software like USAcoil, enter the dimensions of the evaporator, the air flow, the working conditions and you will get the estimated data with a good precision.

Respects and regards

I understand both post...If you know total capacity and sensible....then you know latent capacity as well. The high humidity cases I have been involved in, latent load was really high. By my load calculations latent capacity needed was almost as high as sensible.

I would welcome more to join in on this ..

Thanks to all,
Husky

[HVAC_GAY]

The total cooling capacity i.e sensible heat gain+latent heat gain shall be calculated by design engineer in order to select the unit,in fact supplier or manufacturere will offer you the the range of models ,Then you have to select the unit as per your totol cooling capacity already calculated.it is not the job of manufacturere to suggest u the sensible & latent cooling values,that differs from projsct to project.....

[sinewave]

'Nice' username that! :D


Or was it lost in translation? :confused:

[2007eng]

Hello All,

I have a question I hope you guys can help me with. If you have performed a load calculation, you will know the sensible and latent capacity needed for the conditioned space.

When you are selecting equipment, is it equally as important to know the sensible and latent capacity the equipment will produce? I have always been told it is the manufactures job to provided documentation what the Sensible and Latent capacities are at design conditions. This documentation will give the engineer enough information to make the proper selection. Is my assumption correct?

I had another design engineer argue his point on this subject. He states if you select and size your equipment based on total capacity....that is all that is needed. I'm not the best on load calculations....so I wanted to get some feedback from you guys.

I have had some calls on mold and bacteria into the ductless mini-split Indoor coils. For the most part....the systems with this issue are non-Inverter systems....and located on the coast close to beaches...So my next question is, where is the load calculation? How was the equipment selection process done? Most of all, I can only find a few manufactures showing sensible and latent capacity at design conditions. So I thought maybe I was wrong..

Can you guys please give me some advice here?

Cheers,
Husky

Hello Husky,

I think that if you pring the total capacity you don't need the detailes for selection.
If you think properly you can find that the indoor unit doesn't divides the loads for Sensible and Latent capacities.
Just Heat.(total heat)