Materials Moving Molecules
Dais is developing promising products that use our award-winning Aqualyte™ nanomaterial to
clean contaminated water, control humidity and temperature without refrigerants, and store
energy with a high-voltage, high-energy capacitor.
Nanostructured high-charge-density
electrolyte material
Membrane cross-section
Four key attributes of the material:
5 - 20 nm wide “domain”
Hermetic
- Solid material, no physical pores or openings
Selective
- Discriminates in favor of water molecules
High
Flux - Absorbs and transfers water molecules easily and rapidly
Cost
Effective - Commercially scaled and selling today
Negatively charged sulfonic acid (SO3-) groups are covalently bonded to the
polymer backbone.
The material organizes into hydrophilic (water-loving) charged regions and
hydrophobic (water-repelling) uncharged regions.
These “domains” are typically 5 - 20 nanometers across.
Hydrophilic domains form a conductive pathway across the membrane.
Any difference in vapor pressure between the two sides drives water
molecules to the low pressure side as the domain attempts to maintain
equilibrium, resulting in net transport of water.
Molecular Moisture Transport
Cutaway Illustration:
Membrane
Dehumidification
Dry Air
Membrane Dehumidification
Membrane
Selective transport of water molecules across the membrane makes it
possible to reduce the humidity of an air stream. Drawing the internal
pressure below the vapor pressure of the air directly removes the water
molecules instead of the traditional method of cooling the air stream to
saturation and condensing the water.
Porous
Support
Tube
Advantages of membrane dehumidification:
Humid Air
Low interior
pressure draws
water through
the membrane
Water (H2O)
Oxygen (O2)
Water
Vapor
Cycle
Schematic
Nitrogen (N2)
Roughing Pump
Non-condensable
gases
Ambient
Air
Moisture
Removal
Ambient Air
Exhaust
Air
Membrane Dehumidifier
Dry
Air
Ambient
Air
Compressed
Water Vapor
Independent
control of temperature and humidity - Allows tighter
control of conditions and accommodates situations where
dehumidification is desired without temperature change.
No
regeneration - No heat source is needed to regenerate a desiccant or
drive an absorption chilling cycle, saving energy and/or increasing
application flexibility.
No
desiccants - Traditional desiccants can carry over into the air stream
and pose a hazard to consumers, while Aqualyte is a solid, nontoxic
material that transfers water molecules instead of absorbing them.
Generate
pure condensate water - When a condenser is used to turn
water vapor into liquid water, that condensate is very high purity and
enclosed within a vacuum-tight container, allowing use as potable water.
Refrigerant-based evaporators produce condensate water, but it is
exposed on the outside heat exchange surfaces and picks up
environmental contamination.
Dehumidified
Water Vapor
Vapor
Compressor
output air is well suited for alternative cooling methods Shown separately in more detail, this allows NanoAir to pair with and
often enhance a wide range of highly efficient cooling devices.
Materials Moving Molecules
Cooling Requirements Map of the US
&
Collaborating to develop membrane dehumidification
technology and commercialize innovative HVAC products
BEETIT Phase I: Nanotechnology Membrane Dehumidifier
Funded by ARPA-E ($852,822 total / $681,322 federal)
Completed over 18 month period (3Q 2010 - 1Q 2012)
Membrane
- Characterized performance
Components
- Successfully dehumidified 250 cfm air flow
Commercialization
- Identified preferred path to market
BEETIT Phase II: Membrane
Alternative Cooling Strategies
Dehumidification
Enabling
Funded by US Navy Facilities Engineering Command (NavFAC) and
led by ARPA-E ($1,000,000 total / $800,000 federal)
Planned 12 month project (2Q 2013 - 2Q 2014)
Optimization
- Component design advances improve performance
and reduce system size/cost
Testing
- Demonstrate a dehumidification system that enables
high-efficiency evaporative cooling in humid climates
Commercialization—Leverage
2800 # Cooling Hours/Year
Evaporative cooling works well
Evaporative cooling may work
Evaporative cooling generally not recommended
Source: ARI Unitary
Directory (1993)
200
Membrane Dehumidification allows application of
Bahrain
efficient evaporative cooling strategies to humid
conditions that are usually not viable. Different
evaporative coolers are available:
- Swamp Coolers use direct evaporation and
are limited by the wet-bulb temperature.
- Two-Stage Coolers use indirect and direct
evaporation to achieve temperatures
closer to dew point.
Membrane
- NanoAir chills air indirectly and is
Dehumidification
not limited by the psychrometric
properties of the air.
180
160
140
120
Swamp Cooler
NavFAC use to enter larger markets
100
Two-Stage
Impact of Membrane Dehumidification
80
NanoAir
Expand the reach of evaporative cooling.
Maisotsenko Cycle
Traditionally
limited to Western US (see map, top right), while
Eastern US has highest population and most cooling needs.
dehumidification makes air suitable for evaporative
cooling (see psychrometric chart, right).
40
50%
Membrane
The Maisotsenko Cycle is a continually purged, indirect/direct
evaporative concept. Performance is calculated based on formulas
in DoE/EERE document DOE/GO-102007-2325 (March 2007).
0
50
55
60
65
70
75
80
85
90
95
Chilled
Beam:
cooling, chilled beams, and many experimental HVAC
devices are best suited to dry air to avoid condensation (right).
Passive
sensible
cooling
using
natural
convection
from ceiling
-mounted
chilled
water pipes
Dehumidification
is well suited for Dedicated Outdoor Air System
(DOAS) use, where it removes moisture without overcooling air.
Membrane Dehumidifier DOAS Concept
A
C
J
www.troxuk.co.uk
Radiant
Cooling:
F
D
G
I
Chilled
ceiling or
wall
panels
absorb
radiant
heat from
occupants
K
B
A ― Outside Air (OA) intake
B ― Return Air (RA) inlet
C ― Air filters
D ― ConsERV cores
100
Dry Bulb Temperature [F]
Radiant
E
20
10%
Enable application of sensible-only cooling technologies that
need assistance to handle the latent ventilation load.
H
60
Dry Air
90%
Humidity Ratio [grains water/lb air]
Testing
- Improved and optimized
E ― Vapor compressor
F ― Roughing pump
G ― Membrane dehumidifier
H ― Water removal module
I ― Chilled water module
J ― Exhaust Air (EA) fan
K ― Supply Air (SA) fan
www.spcoils.co.uk