HVAC for high humidity ambients? 2

[rickfer]

We are working in a HVAC project for several buildings located in Guatemala.

Humidity in the area is extreamly high: up to 80%.

So, latent heat is almost as high as sensible heat, and we are having problems for selecting the equipment. Beside AC loads are higher than I'm use to.

Do anybody has an advise on how to lower the humidity for the buildings, with out having very big AC equipments?

 

[KiwiMace]

Pre-condition the outdoor air with a DOAS unit. Then you should be able to use standard equipment selections for the space conditioning units.

 

[MintJulep]

Desiccant wheels to take out some of the moisture from the outdoor air with the relatively dry indoor exhaust.

By way of illustration, and not endorsement:

http://www.gasairconditioning.org/desiccant_how_it_works.htm

 

[317069]

what kind of buildings are they?
and what are the outdoor parameters ?

 

[SAK9]

I do not understand why you are having problems in selecting equipment.Many of the middle eastern countries have summer temperatures of 50C and humidities around 80%.What you need to do is understand the psychrometry involved and design a solution for the condition.By the way DOAS and Dessicant wheels are not usually used for comfort applications in these countries.DOAS may be necessary in certain cases where ventilation rates are high like class rooms etc or in areas usings FCUs.

 

[willard3]

I'm with sak9, learn some psychrometrics and get a psych chart, it's not rocket science.

 

[MechEngNCPE]

Agreed Willard, it may need an 8 or 10 row coil, but its simple psychro.

 

[KiwiMace]

In a big installation ("several buildings"), using a heat recovery DOAS may offer substantial capital and operating cost savings over dozens of 8-row coil air-handlers that might need reheat.

Also likely to be easier to control and meet setpoints more often.

Worth considering both options anyway.

 

[MechEngNCPE]

Yes, probably worth an evaluation.