Showing posts with label thermal. Show all posts
Showing posts with label thermal. Show all posts

Types of thermal insulation materials and their properties

Below we discuss the most common thermal insulation materials. What are their good qualities and what Lambda values have these materials? It is important to know that: the lower the Lambda value is, the better the material insulates. Also true is when the insulation materials gets thicker from 5 cm to 10 cm, for example, that we should not assume that the thickness of 10 cm can isolat 2 times better. On the contrary, the thicker the better, but there is a weakening of the thermal insulation value when the same thermal insulation material get's thicker and thicker. For example: a EPS plate of 60 mm has a Lambda value of 0,085 W/mK, an EPS plate of 120 mm has a Lambda value: 0,035 W/mK.
Go to our conclusion at the bottom of this page to see what's the best insulation material for now and in the near future!

PUR (PU) (Polyurethane)

Can be uses as solid plates and as a foam spray.
PUR is a plastic material made from oil and has the disadvantage that it is highly flammable.
Mainly used in cavity walls.

Characteristics and properties:
- Lambda d-value: 0,027 W/mK.


PIR (Poly Isocyanate)

Plastic produced under addition of catalysts and propellants with isocyanides.
PIR is more improved against fire than PUR. PIR creates less flue gases but is still highly flammable.
Can be both in solid plates, the most plates are coated with a vapor-tight or bituminous layer.
PIR is also flameproof so they are ideal for use in floors and flat roofs, but also in cavity walls.

Characteristics and properties:
- Lambda d-value: between 0,023 W/mK and 0,026 W/mK.
- Heat Storage Capacity c: 1200 J/kgK
- Volume Mass: 30 kg/m³
- Diffusion Resistance (µ-value): 60 - 80
- Fire Class: B, S2, d0

EPS (Expended Polystyrene) (ISOMO)
Produced by suspension polymerization of styrene.
EPS looks like light, white, expanded granules of a few millimeters.

Characteristics and properties: of 60 mm EPS ISOMO:
- Lambda d-value 90/90 ld: 0,038 W/mK
- Volume Mass, where the l-value is minimal: between 30 and 50 kg/m³
- Diffusion Resistance (µ-value): 20 - 50
- Compressive Strength by 10% distortion: 60
- Flexural Strength: 100


ROCKWOOL
Is perfectly fireproof, even against temperatures above 1000°C. In other words non-combustible.
Rockwool encases stationary air. Stationary air is the best natural thermal insulation material.
There is always a seamless connection between the insulation and the material where it can be applied against. Rockwool can be pressed in so you can have a seamless connection between the isolation and the material which in turn increase the insulation value itself, because the fewer holes and crevices, the better insulating between the materials.
Rockwool also ensures an excellent sound insulation. In other words it has a high sound absorption.

Characteristics and properties:
- Lambda d-value : 0,034 W/mK - 0,043 W/mK


CORK
Cork boards are made with cork granules and are 100% natural, derived from the bark of cork oak. By heating the cork it expands so it can get rid of any resins.
Can be obtained in plates or loose grains.
Cork is ideal as floor finish.
Has also an excellent sound insulation.
The insulation value of cork barely takes off with time and cannot be (by nature) affected by mice.
Cork is environmentally friendly because it is almost recyclable for 100%.

Characteristics and properties:
- Lambda d-value: 0,038 - 0,040 W/mK
- Heat Storage Capacity c: 1670 J/kgK
- Volume Mass: 110 - 180 kg/m³
- Diffusion Resistance (µ-value): 25 - 30
- Fire Class : B2


EXPANDED CLAY GRAINS
During the process, air bubbles come in the grain, these provide the insulating properties.
It's for 100 percent natural, because it entirely consists of clay.
It is mainly used as insulating chappe and in concrete applications.

Characteristics and properties of a 15 cm thick chappe:
- Lambda d-value: 0,832 W/mK


Conclusion:
From our equations we can say that PIR insulation is the best thermal isolation for now and in the next generation of buildings where we need more and more thermal isolation. PUR-isolation, which is currently the standard for high-quality insulation applications, will be replaced in the near future by the higher-grade PIR insulation.

Anemometer - meaning (English)

What is an anemometer (short definition)
An Anemometer is an instrument with which the wind can be determined.

Windmill with hemispheres
This instrument was introduced in 1846 by the Irish astronomer Thomas Romney Robinson (1792-1882). This instrument is a rotating windmill with three or four hemispheres (cups) with a rotating shaft rods to be confirmed. The axis is approximately perpendicular to the direction of the wind measurement. The hemispheres are hollow inside. If there are only three hemispheres then they are present prepared at 120° apart. The windmill will rotate because the wind on the concave side exerts more than on the convex side. The motion of the rotating balls through the ashes transform into a dynamo with an electrical voltage signal. The rotation speed of the wind speed are derived. This wind speed is expressed in meters per second or kilometers per hour.

Paddle wheel
Another form of an anemometer is used to measure the speed of the air (mine shafts, air conditioning) in buildings. With this type of windmill has blades in the wing shape or consists of a wheel with blades. The shaft is parallel to the direction of the wind. The weather puts a dynamo coupled motion into electrical voltage.

Ultrasonic anemometer
These motionless sensor is based on the principle that the propagation speed of sound changes with the wind speed. The direction of the wind can be lead and peaks can be measured.

Thermal anemometers
This consists of two heated Pt100 measuring sensors, which are kept constantly in temperature differences. By passing air, the sensors can cooling off. The electric power which is necessary in order to maintain the temperature difference is measured and is a measure of the airspeed.
This type is similar to the classic hot wire anemometer, where the cooling is a measurement of the flow rate of the wind. The cooling effect, for example, a temperature sensitive resistance (NTC) in an electronic circuit, ensures that the wind speed is converted into a voltage or power difference.

Laser Doppler anemometer
Light scattering by particles in the flowing air can also be used as a measure of wind speed. Returning light has twice undergone a Doppler effect, from which speed can be found.


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