Monday, April 14, 2008

Just chill...

I haven't seen much on the blogfront in terms of HVAC and refrigeration since the Freeaire craze of last year (now installed in Killington, VT, where they estimate they're now saving more than 86,389 kilowatt hours of electricity, while eliminating an estimated 58 tons of global-warming CO2 emissions annually!!!), so I thought I might see what's on the horizon...

My search brought me to Ice Energy's Ice Bear, an amazingly simple concept with an equally simple installation procedure (off-the-shelf easy).

Similar to Freeaire, the Ice Bear utilizes cool air conditions to reduce power consumption. Whereas the Freeaire system requires frigid conditions to operate at maximum efficiency, the Ice Bear condenses and freezes water at night when energy consumption is less costly. It then holds the frozen water in an insulated storage tank until daytime when the weather warms.

As the warmer daytime temperatures engage the air conditioning, the refrigerant is forced through the coils in the stored ice and chilled before being pushed in to the building's HVAC ducts, thus providing a cool stream of efficiently refrigerated air.

The Ice Bear® 50 system has a capacity of 50 Ton hours of cooling, including 45 latent + sensible and an additional 5 sensible only. The unit provides 7.5 Tons of cooling capacity for 6 hours of continuous cooling.

Typical configurations:

-7.5 Ton for 6 hours
-5 Ton for 8 hours or more
-Offloading of 10 Ton rooftop unit, where 10 Ton unit is oversized due to high rooftop temperatures
-Offloading one stage of a 10, 15, or 20 Ton, 2-stage rooftop unit

There is also a residential unit capable of eliminating up to 95% of on-peak air conditioning demand. And as an added bonus:

Assists LEED certification

-Adds 3 or more points to the Energy and Atmosphere credits

-Contributes to Indoor Air Quality (IAQ) credits

-Brings Thermal Energy Storage (TES) enabling performance to refrigerant based air-conditioning projects

Now, since the Ice Bear claims to use an equal or lesser amount of energy --in addition to delivering a consistent capacity on 95+ degree days with no degradation in performance and no increase in power consumption-- I'm interested to see if this concept could be hacked to eliminate the majority of the power usage all together.

Consider a location like Kuwait that has an average January low of 45 degrees Fahrenheit and an average August high of 112 (the low for that month is a crisp 83 degrees)! With the exception of brown-outs caused by dust storms throughout June and July, I think it's safe to say that the area is drenched in sun.

So why not saturate the rooftop in solar, submerge the unit's storage containers underground to twice-insulate their exteriors from the harsh conditions,* and store the daytime energy in batteries for nightfall, using the saved energy to refreeze the cores at night?

*You're only depth-limited by accessibility...sink the parking 5-10 floors below the building and you could run the unit subterraneaously, making it even more efficient, but still accessible for repairs. Check some of the commercial case studies and decide for yourself. I think there are benefits that exceed the burden of peak consumption. I just don't have the book learnin' to prove it.