Jigsaw Heating Blog

MiB_Logo_Stacked_Black

About Infrared Heat for Heating

Jun 15, 2020 3:27:04 PM / by Simon - Jigsaw

infrared-heating-difference-1

What is Infrared Heat?

Infrared or IR is a form of electromagnetic radiation with a lower frequency than visible light. It is completely safe (in fact it’s perfect for us). We experience it everyday, whether that's from direct sunlight or the warmth we feel from a surface. 

 

Why use Infrared Heat?

Infrared heating is one of the most cost effective heating systems available, efficiently converting electrical energy into far-infrared heat. We use highly emissive materials in the construction of our heaters, ensuring you get the best heater we can give you. 

Infrared heat keeps you nice and warm in exactly the same way the sun works and it doesn’t waste energy and money by heating empty space. Infrared heating heats objects and people directly (and first) ensuring that you feel the warmth much quicker than you do with convection based heating systems. 

 

How does Infrared Heating Work?

Infrared heat works exactly like the world’s largest natural heater, the sun. The rays of the sun (infrared rays) heat in the main the objects that they hit (rather than the air).

It is easy to feel the difference between having the rays hit your body and when they stop (for example when the sun is blocked by a cloud). I think we've all stood still and enjoyed the sun on our skin, particularly on those cold winter days. 

 

Some Advantages with Infrared Heating

  • EFFICIENT - Up to twice as efficient as other heating systems.
  • ECO - Almost zero energy wastage and emission-free.
  • EASY TO INSTALL - No expensive plumber bills or unsightly pipes.
  • WALL MOUNTED - Or ceiling mounted if you need space.
  • INSTANT HEAT - Infrared heating acts very quickly.
  • ZERO MAINTENANCE - Minimal parts

 

Why is Using Infrared Heat More Efficient

  • 1/3 LESS ENERGY is required to heat a room than convection heat.
  • Infrared heaters can provide the same comfort levels at lower temperatures.
  • Convection heating is subject to HIGHER HEAT LOSS than infrared heating.
  • Convection heat is a far less efficient source of heat transfer than infrared.
  • Convection Heating takes 6% more energy to raise the temperature by 1ºC than infrared.

 

What is convection heat?

First of all let’s consider what convection heat is, and how it heats…

Convection heat is the heat produced by wet radiators or electric air heaters (for example) and is produced by warming air particles, which are fluid and can move from place to place.

As air is heated it moves to places where the air is cooler and therefore transfers heat energy from warm places to cooler places. This is why when you have a draft or open a door you lose the heat in the heated space. It’s also one of the big inefficiencies with convection heat.

 

The science of why hot air moves to colder areas is basically:

As air heats it expands and takes up more volume becoming less dense, the colder air drops into the warmed areas and the warm air is pushed up.

This is convection heat circulation and why with traditional convection heat you heat the ceiling first and the temperature through the room is uneven.

It’s also why when you have a room with minimal drafts and fully heated by convection it feels so stuffy...

 

What is infrared heat and why is it more efficient?

It’s important to understand what infrared heating is. Our explanation is below – here’s the NASA explanation

Every object emits and absorbs infrared radiation and the hotter an object is, the more infrared radiation it emits. Infrared is a form of electromagnetic radiation which involves waves rather than particles like convection heat does.

Infrared is part of the electromagnetic spectrum which is made up of radio waves, microwaves, infrared, visible light, ultraviolet, x-rays, and gamma rays. Infrared sits in between microwaves and visible light waves.

Infrared wavelengths are shorter than microwaves but longer than visible light. Infrared means below red – red is the colour of visible light. Far Infrared is invisible to the human eye. Only rays which fall in a certain spectrum do the heating. These rays are called:

  • Near
  • Medium
  • Far

optimim-infrared-1

 

The best and most efficient for heating is the C Spectrum (Far InfraRed rays, these come between 6 to 10 microns)

Infrared waves only produce heat when they touch a surface such as a wall, an object or our bodies. When the waves touch such a surface the warmth is either absorbed (and then gently released by that object) or reflected to another object where they can be absorbed.

Our heaters all operate within the optimum infrared spectrum.

Another important factor for reaching the optimum IR spectrum is that the heater performs at a certain temperature range. The less input power (W) used to achieve this surface temperature the better the panel, A heater of the same size with the same surface temperature which uses less power is better than a panel which needs more power to achieve the same surface temperature. Our infrared panels all operate precisely within this range.

 

Jigsaw Infrared Heater Radiating Heat to Room

 

Jigsaw Infrared Heaters

 

It is also essential that the heat distribution on the surface of the heater is equal. Only an equal heat distribution guarantees that the total input power is used most efficiently. The image above shows the outstanding heat distribution of our infrared heaters.

 

Thermal Radiation

Thermal radiation is the emission of electromagnetic waves from everything with a higher temperature than absolute zero.

Thermal energy is created by the movement of atoms in matter. Everything with a temperature above absolute zero has molecules and atoms creating kinetic energy. The particles are both positively and negatively charged (protons and electrons).

This produces the emission of photons which radiate energy away. 

Depending upon the surface emitting, the characteristics (including temperature) will vary. 

Made up of a continuous spectrum of photon energies, if the radiating body and it's surface are in thermodynamic equilibrium and the surface has perfect absorptivity at all wavelengths, it is characterised as a black body. A black body is also a perfect emitter.

A perfect emitter will have an emissivity factor of 1. Therefore the best materials for infrared heaters are those with an emissivity factor as close to 1 as possible. This is why we manufacture our infrared heaters in either glass or aluminium which have emissivity factors of 0.95 and 0.9 respectively. 

Absorptivity, reflectivity, and emissivity all have an impact on what makes a good infrared heater. All three are dependent on the wavelength of the radiation.

Emissivity and absorptivity of a wavelength are equal. This means that anything which emits well, also absorbs well. 

Planck's law explains the varying frequency of power that a black body emits. This combined with the displacement law written by Wien indicates that absolute temperature of the black body is in proportion to the peak frequency.

Thermal radiation can be used in a concentrated form with the use of mirrors or Fresnel lenses, conductive and convective heat cannot be concentrated in the same way. Plantar Solar 10 near Seville, Spain show a good example of this. 

 

Interchange of Energy

There are three main types of heat transfer; electromagnetic radiation, convection and conduction. Radiation is distinctly different from the other 2 in that no medium is required to enable heat transfer. 

Thermal radiation varies according to the surface from which it is emitted and the temperature. Thermal radiation can travel through non or partially absorbing objects before reaching an object which is a good absorber. Humans absorb (and emit) thermal radiation very well. 

We (people) lose a lot of energy (heat) through thermal radiation, in addition to the heat we lose to the air surrounding (conductive heat loss) and convection heat loss (heat lost by conduction to the air). 

We regain the lost heat in part by absorbing thermal heat radiation from our surroundings such as walls and other objects. We only gain heat from conduction when the air around us is warmer than our body temperature. Apart from this the other way our bodies gain heat is through our metabolism. 

These are a number of the reasons why infrared heating (thermal heat radiation) is so perfect for us.

Human skin has an emissivity of close to 1.0, this is important (see section below) in terms of infrared heating. 

In science terms, the average surface area of skin is 2m2 and continuously radiates approximately 1000W. Assuming people are indoors they will receive back (from the surfaces that surround us) approximately 900W. Of course these figures depend upon clothing etc.  

 

Emissivity

Surfaces which can radiate or absorb thermal radiation do so in varying degrees of success. Emissivity is the ratio between thermal radiation of a surface to the radiation from an ideal black surface at the same temperature. The surface of the perfect black body will radiate at approximately 448W per m2 at 25ºC.

The table below shows the emissivity of some common materials. You can see why we choose to manufacture our infrared heaters in aluminium and glass. 

 
Material Emissivity
Aluminium foil 0.03
Aluminium, anodized 0.9[12]
Asphalt 0.88
Brick 0.90
Concrete, rough 0.91
Copper, polished 0.04
Copper, oxidized 0.87
Glass, smooth (uncoated) 0.95
Ice 0.97
Limestone 0.92
Marble (polished) 0.89 to 0.92
Paint (including white) 0.9
Paper, roofing or white 0.88 to 0.86
Plaster, rough 0.89
Silver, polished 0.02
Silver, oxidized 0.04
Skin, Human 0.97 to 0.999
Snow 0.8 to 0.9
Transition metal Disilicides (e.g. MoSi2 or WSi2) 0.86 to 0.93
Water, pure 0.96

 

In summary, we put a lot of thought into the design and the manufacture of our infrared heating. This ensures high emissivity and high thermal radiation, which is perfect for warming the human body. 

Infrared heating provides a comfortable and cost efficient way to heat us and our homes. 

We'd be pleased to help you get the best and most efficient heating solution for your home or workplace. 

Get in touch if you would like more information on how you can work with Jigsaw.

View The Range

 

Tags: efficient heating, smart heating, how do infrared heaters work

Simon - Jigsaw

Written by Simon - Jigsaw

Involved in the Infrared heating industry for over 10 years. Developing the Infrared Heating industry in the UK and Europe. Refining product manufacture, design and implementation. Promoting the concept of using infrared heating in both the domestic and commercial environment and the efficiencies this creates.

EFFICIENT, COMFORTABLE HEATING. FOR YOU.

BRITISH MANUFACTURED / BRITISH TESTED & CERTIFIED

Our goal is to help you modernise your heating system, save you money on your energy bills and add value to your home.

Recent Posts