We are designing a home in the Caribbean and need help with air-conditioning options. Can you provide us with some advice?

Asked by Tish B.
Miami, FL

We are building a home in Grand Cayman which is designed as much as possible to exclude the amount of sun coming in and also to allow for cross-ventilation through the building. There will, however, be times when we will need to use air conditioning. We have been advised that ductless split systems are the most efficient. Is this true? Also, what are the options for geoexchange and is this type of system likely to work in our hot, humid climate (noting that we are very close to sea level -- thus there is also the issue of corrosion)? Which is going to be the most energy efficient but at the same time effective method of cooling?


Polly Osborne, FAIA, LEED AP

Answered by Polly Osborne, FAIA, LEED AP

Los Angeles, CA

Polly Osborne Architects

October 15, 2010

Ductless heat pump air conditioners are very efficient.

  • Be sure to have it sized both for the amount of cooling you need and also for the amount of humidity you have.
  • The good ductless models have a pump and drain system in them to remove excess moisture, and this has to be sized to fit your climate. When you haven't used your unit for a long time, you need to clear this part by running it on fan-only for a while to dry it out.

Ductless heat pumps are not invisible, so they can be disappointing from an aesthetic point of view.

  • LG has one that you can use as a picture frame, but it has a very small capacity unless they've come out with a new model recently.
  • Daiken has some very efficient models, but they don't win any beauty pageants.

For more information:

Randy Potter recommends the Fujitsu Halcyon heat pump in his Q&A "I can't afford geothermal. Is an air-to-air heat pump my best option for heating?"

Read Cynthia Phakos's Q&A "How can I remodel my oceanside property for maximum energy efficiency?"

Tagged In: heating cooling, summer energy

Do you have a question about greening your home? GreenHomeGuide invites you to Ask A Pro. Let our network of experienced green building professionals – architects, designers, contractors, electricians, energy experts, landscapers, tile & stone specialists, and more – help you find the right solution.