Eureka! The Solar Driven, "Water-Fired" Chiller-Heater
by John Laumer, Philadelphia on 04.30.07
This hybrid HVAC tech is so cool and so hot - including the possibility of using direct solar collectors to cool and heat our buildings- we're surprised it hasn't had very much media coverage of late. From the Yazaki Energy Systems, Inc. web site (Plano Texas, USA) Yazaki water fired SINGLE-EFFECT chillers or chiller-heaters have cooling capacities of 10, 20 and 30 tons of refrigeration and produce chilled water for cooling or hot water for heating in comfort air conditioning applications. The absorption cycle is energized by a heat medium (hot water) at 158°F to 203°F from an industrial process, co-generation system, solar energy or other heat source and the condenser is water cooled through a cooling tower. Absorption Principle:- The Yazaki absorption chiller or chiller-heater uses a solution of lithium bromide and water, under a vacuum, as the working fluid. Water is the refrigerant and lithium bromide, a nontoxic salt, is the absorbent. Refrigerant, liberated by heat from the solution, produces a refrigerating effect in the evaporator when cooling water is circulated through the condenser and absorber.
A web post barely scratches the surface of all that needs to be discussed. But, we hasten to point out several things. One is that waste heat from other commercial machinery can be added to the solar heat input. Another is that LiBr refrigerant recycling is commercially possible. TreeHugger strongly suggests spending some time reading about the existing installations pictured here.
Nothing is without risk. Proper caution will be necessary on encountering anhydrous LiBr because skin contact may lead to burns as a result of substantial dehydration.
DukeSolar now http://www.solargenix.com/ does just that, using Vacuum tube solar panels to do AC.
Back in the 1980s I designed a solar pyramid home using a Yazaki heating and AC system in Tempe, AZ. (this was originally developed by the late Dr. John Yellott of ASU). The system worked great but was a bit complex and cost over $17,000 back then. Today that sounds like a bargain!
The hotter it got outside the better the system worked and the more cooling it provided. I coupled this lithium bromide AC to a ground mounted evaporative cooler that blew 5800 cu. ft./ minute into a pressure treated wood foundation crawl space under the pyramid home to provide additional cooling. The pyramid's shape was its most efficient feature here as unwanted hot air naturally collected at the top and was blown off the apex by a temperature actuated fan/vent system. The home enjoyed AC and heating for a fraction of the cost of conventional systems and even at that high installed price had a payback of seven years.
I would certainly like to do another of these solar powered HVACs on my present day (evolved) pyramid homes, if the cost is reasonable. Cost efficiency is a key to success and must be considered. I'm using evacuated tube solar panels on all my homes and that is a significant improvement over flat plate panels of the past.
I'am very interested in what is going about this. Is there any company comercializing the product?