August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica NANO-HVAC GA no : 314212...

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


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


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


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


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


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


Development of innovativeaeroclay-based insulating foams

Clay-based aerogels = aeroclays


Clay minerals

Stacked sheet structures Different combinations of tetrahedral and

octahedral sheets form different clay minerals

https://www.google.be/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCNXRkeDvw8cCFcgwGgodM9YGaA&url=https://gsoil.wordpress.com/tag/clay/&ei=_S7cVZXfIcjhaLOsm8AG&psig=AFQjCNFlk4yv366bGjXygfy0ZJ1u8bakzQ&ust=1440579677863476

http://www.google.be/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCI2Y3Ozxw8cCFYbbGgodSxkFpA&url=http://www.slideshare.net/1234567ses/cec-14594689&ei=MDHcVY3AMYa3a8uylKAK&psig=AFQjCNFlk4yv366bGjXygfy0ZJ1u8bakzQ&ust=1440579677863476

http://www.google.be/url?sa=i&rct=j&q=&esrc=s&frm=1&source=images&cd=&cad=rja&uact=8&ved=0CAcQjRxqFQoTCIKassjxw8cCFQG1GgodusoHlg&url=http://www.slideshare.net/1234567ses/cec-14594689&ei=5DDcVYKYJoHqarqVn7AJ&psig=AFQjCNFlk4yv366bGjXygfy0ZJ1u8bakzQ&ust=1440579677863476


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


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


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


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


Preparation of prototype ducts

Injection in double walled moulds

Scaling up problems optimisation experimentsDensity increasesThermal conductivity increasesAvailability of aeroclay


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.


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


• 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


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


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


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


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


Energy performance testing of full scale demonstrator - setup

Pipes on rooftop


Energy performance testing of full scale demonstrator – set-up

Reference mineral wool tubes

nanoHVAC insulated tubes


Energy performance testing of full scale demonstrator – set-up


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


Improvement of upscaling

To reduce density and heat conduction values of nanoHVAC material



Density decrease was obtained


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


Thank you for your attention!

August 28th, 2015, Lavrion Technological and Cultural Park (LTCP), Attica NANO-HVAC GA no : 314212...

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