Night Radiant Condensation System

The XDOBS night radiant condensation system is a water-from-air extraction system and air conditioner that does not use any external electricity or fuel. Power is provided by an integrated solar panel. The system uses almost no moving parts, consuming 95% less energy than conventional AC systems, and is powered by an integrated solar panel.

It produces water by chilling the local air below dew point temperature. The incoming air is filtered through a HEPA-type filter to remove dust and bacteria so that the water is potable.

In arid climates, the best use of the system is for air conditioning. The system uses Night Radiant energy to send heat into the night sky. Overall, the system reduces HVAC electricity consumption by 80%, and as much as 90% during peak demand hours.

In third-world, humid climates, the best use of the system is for potable water harvesting.

Radian Cooling has been used by NASA to cool space craft, and has been tested in the Pacific Islands and Egypt. It is used to cool large telescopes world wide, as well as to chill large-scale cryogenics

The following elaboration of components is compiled from the two pdf documents prepared by the company.

Night Radiant panels

Shed heat to night sky or day sky when shaded 100 to 400 watts per sq meter. Chills thermal storage fluid, reaching 10F to 20F below nighttime ambient.

• Designed to minimize convection and conduction and maximize radiation heat transfer
• Designed to last over 20 years in outside atmospheric conditions
• Dissipates between 100-140 watts of heat /square meter panel
• 33 square foot per gallon per night
• 8.8 square foot per liter per night
• Produces 4950 liters per acre per night

Thermal / Wind Shield

Prevents convective warming of panel surface which allows extra chilling. Creates cold, horizontal stagnant insulating area which increases efficiency and minimizes thermal gain from surface dew.

• Helps reduce the temperature by 3F
• Should be installed in area where wind speed is greater than 3 MPH. Effective to 8 MPH.

Optional Wind boost

Directs wind away from panels while using wind energy to provide 4 - 7F of additional chilling.

• Increase production by 50% with 7 hours per night of 8 MPH wind.
• Allow system to be used in warmer and drier climates

Primary Heat Exchanger / Condenser

Transfers cold from the thermal storage fluid to indoor air. Several different types exist, but the cheapest is basically a set of 280,000 BTU radiators.

• Chills air during high absolute humidity time of the day
• Provides condensing surface for the water
• Precisely controlled to maximize condensation
• Exit air can be used as conditioned air for cooling
• Effective when thermal storage fluid is at least 2F below current dew point.
• Note: systems without thermal storage must do condensing during the night.

Thermal Storage Tank

A tank of fluid which contains the chilled fluid until needed for cooling purposes. It is normally insulated and buried to retain cold. Average is 3,000 gallons per 1,000 square foot per day of storage.

• Optional use for improved performance
• Stores cold at night to use during best humidity conditions
• Sized as 120 to 300 gallons per gallon of condensate per day
• Average system requires 60 to 120 days of production to replace water invested
• Salt water can be used
• Tank is usually provided locally
• Existing cisterns can be used for thermal storage with addition of insulation

Micro Controller, Pumps, Valves, Blower, Solar charger, Battery

These components control the circulation of fluid to maximize chilling to panels and circulation of fluid to heat exchangers to maintain desired room temperatures.

• Controls thermal conditions for optimal broader range of operation
• Thermosyphon is used whenever possible to eliminate or reduce pumping power
• Thermal drop concept is used for air flow to eliminate fan energy
• Heat pipe can be used to eliminate pump energy
• Optional Geoexchange heat pump can supplement water production during marginal conditions.

Optional Thermal Chimney

This is a different kind of heat exchanger. It looks like a chimney and uses diffusion type cold air release at the floor. It runs completely silent and uses convention to drive air flow, eliminating the need for most HVAC ducts. It is ideal for retrofit installs.

Advantages

• Provides ROI over 10 times better than photovoltaic solar panels at 2007 prices.
• Can delay or remove need for major grid upgrades especially in areas with peak demand failures.
• Eliminate need for rolling blackouts caused by excess power demands in the summer. (Air conditioning electricity demand is the leading cause of summer blackouts.)
• Reduce standby generating requirements by up to 50%.
• Dramatically reduce indirect greenhouse emissions for equipped buildings.
• Incidental benefits:
  • Dramatically reduces roof wear due to solar exposure.
  • Dramatically reduces heat gain through roof.
  • Dramatically reduces attic temperatures.

Applications

• Off grid guard shacks.
• Locations with expensive power such as Diesel or propane generators.
• Areas with high peak demand power costs.
• Locations with High human cost if cooling is lost during power outages such as nursing homes and hospitals.
• Buildings that must stay operational during power outages such as police and fire stations.
• Businesses in areas where peak demand is causing high risk of grid failure.
• Areas where large scale grid upgrades are needed to meet increasing demands.

Patents

Portions patent pending.

XDOBS, an energy, water, and greenhouse emissions research compay, was founded in 2003 by Joseph Ellsworth, a Silicon Valley entrepreneur with strong embedded systems and software optimization background. The company has been privately funded by its founders.

The company does not plan to manufacture and market the technology but is entertaining licensing agreements.

XDOBS is seeking test partners who have invested renewable solutions in the past, and who manage buildings that are off grid or who have expensive peak demand power and need cooling, who may have larger needs pending successful test outcome, and who would help publicize the results of the tests.