Join Date: Jul 2000
Thanked 177 Times in 166 Posts
Rep Power: 17
Re: Solar powered cooling
The downside to zeolites (chiefly activated alumina) is the HIGH energy needed for regeneration - 'roasting' the zeolite 'bed' for 8 hours at 350°F, plus cool down. The alternative is 'pressure swing' zeolite regeneration using a partial diverted flow of produced dehydrated gas/air (-40° dewpoint) but which consumes even more energy overall than 'heat swing' methods. The question is from where will you generate the power to operate the 60-100 psi needed for this zeolite regeneration to be accomplished in the 8 hours? Cant generate the pressure - no problem if you can wait 8 days for regeneration.
Sorry, but the 'compactness' of fossil fuels (gasoline @ 22-24000 Btu/pound or ~114,000 BTU/gallon) running a simple 2000 watt generator plus 'capacitance starter' powering a ~6000 BTU AC unit is still 'light years' ahead in efficiency and operating cost for cooling a boat.
To run an equivalent 'solar' installation for 6000BTU (100BTU/min) you'd need a panel output of 1700+ watts .... about 5 square meters (~55 sq. ft) of solar panels, something much beyond the entire surface area of the typical sailboat, ...... of course only to be run between 10AM to 3 PM on bright sunny days.
Got a small barge you can tow along to hold all those solar panels?
Actually a direct fired propane driven system, such as used in the 1930s is still viable and very efficient using one of the modern environmentally less damaging 'freons', instead of ammonia. Bring your mortgage application when you consider propane/CNG driven cooling, and then expect a routine monthly EPA inspection and mega-hassling.
Nothing in life is free.
Not to 'knock you down' on inspiration; but, the use a zeolites for sub-cooling simply wont 'do it', although they can reduce the uncomfortable 'humidity'. So, keep your thoughts, and keep trying !!!!
Last edited by RichH; 02-21-2014 at 03:59 PM.