Buildings in Hot Climates

[friartuck]

I am interested to know how buildings are constructed in hot humid climates. (Jamaica, Bermuda, Antigua)

Is it beneficial to insulate them against heat or is that a ridiculous statement.

My theory is that if you have a poorly insulated concrete or wooden roof, it will let more heat in.

So by adding some insulation in the right place (at the roof) but keeping heavy high density components internally to act as a heat sink.(i.e. concrete internal ceiling, block walls, tiled floor etc.)

In the UK we generally have new builds which are very light weight and high insulated to give U values of 0.35W/m2K or less for wall and 0.15 for roofs.

Anyone have any knowledge on this subject.

Cheers


Friar Tuck of Sherwood

 

[AbbyNormal]

Bermuda needs space heat in the winter. Jamaica perhaps there is some chill in the mountains.

But I think in Antigua, its going to be year round cooling like here.

What I find is it does not really matter so much what the temperature is outside, what matters the most is how sunny it is and how humid it is. Rainy season here the dewpoint will hower around 26-27C.

In my opinion, something like insulated concrete forms is 'diminishing returns'.

Concrete is more durable, framed construction with fibre glass is prone to providing infiltration pathways, and the infiltrating air will most likely have a dewpoint higher than waht the space is maintained at. Fiber glass will filter the infiltrating air. Icyene foam in a stud space stops air movement.

A framed wall space also is a haven for insects.

Concrete gets externally insulated with foam here, I gave links before showing many building techniques.

If you run some loads and opt to go for decent R values, low U-values, then I would recommend a means to independently control humidity.

I think the best approach is a sealed envelope that gets pressurized with dry air. I would recommend sealing an attic and not venting it. I am almost finished building four apartments of my own here. My roof is externally insulated and the insulation is covered with white standing seam metal roofing.

They use the royal building system here as well, it is a series of vertical vinyl forms even available preinsulated, that you fill with concrete. If you like the drab look you have a finsihed wall when you are done. However often they will coat the exterior walls with marmarand 'synthetic coloured stucco'



Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[AbbyNormal]

Is your firm the architectural firm as well?

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[friartuck]

Abbynormal

Thanks for the reply,

No, we are building services designers only, but the Architect might need a bit of help.

With regards to air con, I was thinking of using Daikin or Mitsubishi 'splits' which have a special dehum cycle so we can get rid of some of the humidity.

My concern is how we fix them. I assume that I would need to bolt them down (Due to Hurricanes)

I also am looking for a decent solar panel (water type).

In Europe there are many good mnufacturers, but I don't think they make ones that can stand a 100mph wind. Also wouldn't the glass get broke. Is there a manufacturer that has a hurricane resistant design??

Thanks in anticipation

Tucky





Friar Tuck of Sherwood

 

[AbbyNormal]

My advice from eight years of the tropics is to pressurize with dry air. Hard to ventilate with ductless spilts.

If the glass is half your load, consider what happens when it is humid out and no sunshine.

There is imact rated glass, there are shutters, there is also plywood.

It is easy for glass to take the pressure of winds in excess of 100 miles per hour. The problem is flying projectiles.

Check out this thread javascriptpenindex(450,450,'

http://www.tipmaster.com/includes/refinfo.cfm?w=450&h=450')

Pictures of my retirement investment here. The glass is rated for 140 mph. I am using extruded aluminum channels (not installed yet) to take ply wood for protecting the windows. I have built up a wood frame as a trim around the garden doors in the photo and will install some of the aluminum frames there to protect the doors when a storm threatens.

Impact glass probably will take 3 hits at 35 mph by a flying '2x4' (8 foot lumber) without breaking to meet Dade County rules.





Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[SAK9]

HVAC in humid climate is tricky business.If you are designing for a hotel,better pretreat the air to around 12C and reheat it to room temp.This would ensure decent humidity levels even when the FCUs are off(assuming fresh air is not turned off).

Otherwise the humidity will be really high on a cloudy day(no sensible load)as Abby pointed out

 

[friartuck]

The project is a mixture of holiday homes (single storey and 2 storey) with a central restaurant/bar and a swimming pool. (Very posh)

Air-Conditioning

I have looked at a few manufacturers, but can you suggest any American suppliers/manufacturers that might be ok to use.

I am concerned that if I use Japanese/European equipment, spares might be an issue. But if I use USA equipment, the mainland is just a hop and skip away, so spares would hopefully be easier to obtain.

Ventilation

With regards to ventilation, the site is very close to the sea.

Am I better relying on natural vent or do I really need to mechanically ventilate.

If I do, then presumably I have a roof space that I could fit a small air handling unit in. I could incorporate a small DX cooling coil and reheater (But is this over the top for holiday homes??--- P.S. who makes a suitable ducted unit with dehum/reheat)

Daikin and Mitsubishi units have a special dehumidifier function which is designed to removes high levels of humidity from the air. Would this not be sufficient due to the very high humidities??

I presume that the Japanese market doesn't have a humid climate like Antigua. (I'm glad I don't get these problems in the UK)

Also, is damp a problem?? even with the high ambient temperatures?

Sorry to be an inquisitive pain in the ass but your help would be very much appreciated



Friar Tuck of Sherwood

 

[AbbyNormal]

Use American Brands, readily available out of south florida, the supply hub for the Caribbean

Natural ventilation implies you are going to allow air in with a dewpoint higher than the temperatures you want to maintain. Suggest washroom fans and a fresh air intake to the return air of the air handler

If the sun is not shining but the humidity is high, can be porblematic. So the damp is called 75% RH and a potential for mold. Suggest supplimental dehumidifier if the load is working out to be half fenestration.

Electric reheat can be pricey especially if the electricity is diesel generated. A little standalone dehumidifer reheats using the same heat used to dehumidify.

If you are close to the sea aluminum fins in contact with copper tubes will corrode. Ask client if they want cheap and sacficial or expensive and durable. The all aluminum spinefin coils by Trane/American Standard will outlast ALL coated coils.

If wave action is a threat salt water always wins. May want sacrificial and cheap.


Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[friartuck]

Great ideas. Really helpful, thanks.

Solar Panels

Are there any preferred solar panel people in the area. We normally use German manufacturers such as Viessmann, but they might not be suitable since they have glass panel fronts.(Easily breakable in high winds/hurricanes)

Perhaps a simple black steel panel with a drainback type cylinder.


Water Storage-Drinkable Supply

Also, we have a situation where there may not be much water available and it might be unreliable supply.

Would you use an underground water store (which might get flooded and the water in it ruined--but would keep cool and fresh for most of the time) or would you use an above ground tank (Which would need a housing and could get very hot--legionella risk)

If we use an above ground tank,(to stop contamination from high water levels) I was thinking of fitting an AC cooling unit in the building housing it. (Am I being a bit extravagant here?)

I could also put water tanks in each of the holiday homes to reduce the main water store I suppose.


Help!!!

Thanks in anticipation

Friar Tuck of Sherwood

 

[AbbyNormal]

Underground cisterns are common here, still used in areeas where the muncipal supply is not piped.

They collect rain water and have it trucked in, however always a concern with open to atmospheric storage, besides germs there are frogs. May want a filtration/germicidal system like on some wells, see UV used sometimes.

Drink bottled water and wash flush toilets with the tap water.

Some resorts have their own RO plants.



Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[friartuck]

Abbynormal

Where do you live?

Antigua or somewhere nearby. Sorry for being nosey.

I tried the link on one of your replies but couldn't access those retirement houses you talked of. (perhaps the link has been removed??)

Never heard of Frogs being a nuisance, that sounds quite funny. I ate one once in France (Well a leg anyway). Tastes like chicken.


I think the RO plant sounds like a good idea. At least we won't poison anyone.

Our on site plant room seems to be getting bigger.

I think we might have to beg the Architect for a large plant room compound.

Thanks for the help



Friar Tuck of Sherwood

 

[AbbyNormal]

Grand Cayman

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[AbbyNormal]

Grand Cayman

Go to the Reflective Foil vs Insulation thread here

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[AbbyNormal]

Speaking of frogs, maybe terminate condensate drains with a 90

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[AbbyNormal]

or underground to a french drain or a 'soak away'

products out there to filter UV/chlorinate and then pressurize/store condensate for potable re-use, expensive though, ever watch/read Dune?

Take the "V" out of HVAC and you are left with a HAC(k) job.

 

[atlas06]

Guys,
I wanted to suggest to use that stinking insulation that I forgot the name of, is it cellular glass? for such a climate.
Have you looked into a "cold" system? i.e supply air at 47F (your little Mitshubishi's won't do though), works well in southern US states.