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August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
NANO-HVAC GA no : 314212 Novel Nano-enabled Energy Efficient and Safe HVAC ducts and systems contributing to an healthier indoor environment
Final Dissemination ConferenceLavrio, 28th August 2015
Nano-HVAC insulation product performance and its contribution to the reduction of energy losses in HVAC systems
Heidi Van den Rul
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Background
Heating, ventilation and air conditioning (HVAC) Represent 33% of the energy used in commercial facilities
14% space heating 10 % space cooling 9% ventilation
Cooling % will increase climate changeheat releasing equipment in buildings Priority target:
Energy-efficient buildings Ducts are not insulated well at the moment
Can loose up to 50% of the energy used to heat and cool
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
nanoHVAC project
Novel nano-enabled energy efficient and safe HVAC ducts and systems contributing to a healthier indoor environment
Develop an innovative approach for ducts insulation Safe, high insulating HVAC ducts
Minimizing heat/cool losses
Cost-effective, thin insulating duct layers
Applicable on circular ducts and square ducts
Automatic application
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
High efficient insulation Heat conductivity < 0.020 W/mK
Cost-effective insulation material Light material
Density < 30 kg/m3 Automatically applicable
No manual wrapping Sprayable or injectable casting Curing time minimal
Fire resistant properties Complying with the strictest EU standards (A1/A2 class)
Water and salt resistanto 50% saving in energy losseso 45% reduction in duct cost (compared to conventional insulated ducts)
Requirementsinsulation material for HVAC tubes
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Traditional insulating materials?
MaterialMineral wool
glass woolstone wool
Organic foams polystyrene
polyurethane
heat conductivity 30-45 W/mK 30-45 W/mK
temp. range of use wide low temp.
fire resistance x 0
moisture resistance 0 x
Need for inorganic material (fire resistant)
with high insulation quality (thin layer) that can be sprayed/injected
and is cheap
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
High insulating materials
Insulating materials with heat conductivity < 0.020 W/mK VIPs vacuum insulations panels
Silica aerogels High specific surface area, high porosity Low density High thermal insulation But weak and brittle
aerogel composite materials High production cost
developments towards lower costs Moisture sensitive
Hydrophobic aerogels
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Development of innovativeaeroclay-based insulating foams
Clay-based aerogels = aeroclays
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Clay minerals
Stacked sheet structures Different combinations of tetrahedral and
octahedral sheets form different clay minerals
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Aeroclay
Swelling of clay in a suspension
Maintain the expanded structure / avoid shrinking by freeze-drying aeroclay Structure with high amount of air High porosity, very low density Unexpensive raw materials Good insulation properties But: mechanically weak
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Aeroclay based composites
Addition of polymers/fibers increases the strength In this project: combination of aeroclays with
foamed inorganic binders Inorganic binders:
Silicate binders (sodium silicate) Polymerized silicate = silica gel = strength Mechanical properties depend on various experimental
parameters (hardener, type of silicate, viscosity, reaction speed…)
Formulation of foams Using foaming agents (surfactants) Using blowing agents (decomposing products producing
gasses) Addition of fibres to improve the mechanical properties
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Procedure
Blowing agent
Tensioactive additive
pore stabilizer
Catalyst + hardener
Prefoaming Mixing the
prefoam with binders and fillers
Spraying with catalysts incorporated through a nozzle
Casting in moulds Curing
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Characterization of samples
sample density (kg/m3)
thermal conductivity
(mW/mK)
compressive modulus
(MPa)
0% aeroclay 215 37 5,0
1% aeroclay 156-243 33-38 4,0
2% aeroclay 77-108 26-30
3% aeroclay 182-201 34-36
3% aeroclaynew lab
procedure94-107 27-30 4,1
Addition of aeroclay reduces the density (2%) reduces the thermal conductivity (2%)But: reduces the mechanical properties
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Preparation of prototype ducts
Injection in double walled moulds
Scaling up problems optimisation experimentsDensity increasesThermal conductivity increasesAvailability of aeroclay
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of prototypes in lab scale system
Three systems are constructed in a climate chamber environment at Sirris (Belgium), using a closed loop system and tubes that are (i) not insulated,
(ii) insulated with mineral wool
and (iii) insulated with the new nanoHVAC material.
The insulation performance of the ducts is evaluated and compared in terms of temperature distribution and energy consumption.
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing - set-up
an air handling unit with heating feature and fan.
a control system to keep the temperature in the system at a constant level (a thermostat)
an identical set of air ducts of diameter 125 mm
Measurements devices: Power consumption
measurement of the heating element
Temperature measurement
Thermal camera to detect leaks and temperature losses
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
• 3 identical set-ups with same dimensions and same heating element/fan, inserted at same position
• Installed in a climate chamber, all at the same position for the evaluation• Set-ups are installed above the ground• Insulation gaps for nanoHVAC tubes are equalized with PUR foam, and
because of small damages the nanoHVAC system is wrapped with Al tape
Energy performance testing - set-up
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing - experiments
Cool down chamber to -5°C Allow the tubes in this environment till the temperatures in the tube is -5°C Put on the heating, heating up the air inside the tubes to a set value of
35°C Keep the temperature at 35°C for 3h Let the system cool down (no heating, only ventilation) Monitor the power consumption and temperature
Analyse the heating up, steady state and cooling down period
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing - results
The nanoHVAC system has a -value comparable to mineral wool
The nanoHVAC system has a higher heat capacity than mineral wool
Why difference between lab-scale and scaled-up product? Difference in density
Higher density = higher heat capacity Higher density = less air = higher value
Density (kg/m3)
nanoHVAC tubes Measured in delivered system
127
nanoHVAC bends Measured in delivered system
115-120
nanoHVAC labscale material
Indicated in previous reports
80-110
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing - thermal camera data
Blank systemHigher surface temperatures, much heat loss
Wool systemHeat losses at the heater + bends
nanoHVAC systemHeat losses at the heater
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of full scale demonstrator in a demo
building 2 full-scale test-cells @ Madrid
Reference – tubes insulated with mineral wool
Demo – tubes insulated with nanoHVAC material
Positioned to avoid shadowing effects Thermal monitoring identical U-values and
composition
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of full scale demonstrator - setup
Pipes on rooftop
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of full scale demonstrator – set-up
Reference mineral wool tubes
nanoHVAC insulated tubes
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of full scale demonstrator – set-up
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Energy performance testing of full scale demonstrator - results
Identical energy consumption behaviors for both set-ups (nanoHVAC and mineral wool) Mineral wool 1.44% lower
identical -values
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Improvement of upscaling
To reduce density and heat conduction values of nanoHVAC material
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Improvement of upscaling
Density decrease was obtained
August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica
Conclusions
A new insulation material was developed Based on aeroclay + inorganic binders as foam
The new material has lower thermal conductivity values than mineral wool – on labscale
Upscaling the synthesis procedure resulted in an increased density and thermal conductivity for the material – the energy improvement of ducts insulated with the new material is comparable to ducts insulated with mineral wool
The upscaling procedure was optimized reducing the density again.
More improvements required before the material can be utilized in applications