Key differences: Radiant Vs convection heat

Radiant heat warms objects and surfaces without heating the air in between. Those objects warm up directly and radiate back.

Convection warms the air, which is a triple inefficiency. The air has to:

  • Warm up. Air absorbs heat poorly;
  • Travel (unforced convection of heat is always upwards to the ceiling or through doors and windows. Only forced convection – using a fan – convects heat horizontally );
  • Deliver the heat to something. Air transfers heat out poorly;

Degree for degree °F, radiant heat delivers the heat transfer capability of convection to the power of 4 (Boltzmann’s law).

CONVECTION

Diagram showing heat transfer by convection and how it requires 3 inefficient steps to deliver heat
  • Heat exchange has to occur twice (indirect heating of objects)
  • Air absorbs & retains heat poorly
  • Hot air rises and is prone to infiltration loss (draughts)
  • Air heats thermal mass poorly, so when the heating stops, so does the warmth.

RADIANCE

Diagram showing the direct (single step) emission of radiant heat directly from source to target
  • Heat exchange occurs once (direct heating of objects)
  • Most domestic materials absorb & retain heat well
  • Less prone to infiltration loss in an enclosed space
  • Excellent priming of thermal mass = when heating stops, residual heat is left in the building.

Advantages for heaters

The advantages of radiant heating over convection:

  • Heat transferred (watts / foot / second) grows exponentially with temperature rise. Convection heat transfer grows only linearly with temperature.
  • You require less installed capacity in a radiant heating system
  • You don’t need to run it as long
  • You can apply heat only where you need it – you don’t need to heat the whole room
  • You can control it more precisely

Types of radiant heaters from Herschel

Herschel Infrared Heaters

Infrared Panel Heaters– these are mostly used in residential and office applications.

Hot Yoga / Bikram Infrared Heaters – for reaching temepratures up to 113°F

Infrared Space Heaters – for heating larger enclosed or sheltered outdoor spaces

Outdoor Infrared Patio Heaters – for heating unsheltered areas (e.g. patios) or colder indoor areas.

Herschel Interactive House

Click on each room for inspiration on how to use Herschel’s efficient infrared heaters in your home.

Herschel Inspire Panels

Frequently Asked Questions

How do Herschel infrared heaters work?

We could get really geeky on this but will try to keep it simple…

Herschel Inspire infrared panels convert electricity to emit radiant heat called “far infrared”. Surface temperatures of the Inspire average 200 degrees Fahrenheit and are designed to gently warm people and buildings.

Herschel Advantage IRP4 and Aspect XL range utilise ceramic plate emitters containing nickel wire cores.

Herschel Far Infrared emitters emit in the spectral range of 3 – 10 microns with no light at all.

The Herschel Advantage and Aspect Space heaters have surface temperatures of around 750 degrees Fahrenheit and have a higher throw and spread to heat larger areas.

The majority of the heat produced from all of our panels is “radiant”, meaning the energy is used to directly heat objects an

Is infrared heating safe?

Is infrared heating safe?

Are Infrared rays safe for people?

Image showing the Infrared emitted by the human bodyFar infrared heating is 100% safe and natural for our bodies, and our well-being, as the human body is designed to accept and emit infrared. The feeling of warmth from infrared is particularly comfortable. It is UV that is harmful, not infrared, and so there is no need to worry.

 

Infrared Heating is a totally safe and natural for of heating for peopleThe water in our skin responds well to this particular wavelength of heat which is why it is also called the “Vital Range” of heat. This is why Infrared heaters feel so comfortable. Far Infrared rays are the same heat you would feel off a sandy beach or rocks warmed up in the sun.

People feeling an infrared heater for the first time say it is like walking past a window that the sun is shining through.

Is Infrared harmful at all?

International Commission for Non-Ionising Radiation Protection (ICNIRp)The International Commission for Non-Ionising Radiation Protection (ICNIRP) has conducted numerous investigations into the health effects of different types of Infrared and is the resource that national bodies like the UK Health & Safety Executive refer to when setting safe working conditions. The ICNIRP concludes that for known artificial sources of Far Infrared, the “contribution made by the IR-C spectral region 3-1000µ is normally of no practical concern from a health hazard standpoint”.

Do Infrared heaters emit Ultraviolet? Are there any health risks?

Position of Infrared in the electromagnetic spectrum relative to ultravioletAlthough often compared to the “heat of the sun” Far Infrared panels do not emit ultraviolet. Ultraviolet is on the “high energy” side of the Electromagnetic spectrum and is associated with the harmful effects of exposure to the sun. At the opposite end of the spectrum, infrared is on the “low energy” side of the Electromagnetic spectrum and does not have any of the harmful characteristics of Ultraviolet. Far infrared, the gentlest form of infrared, is often used in incubators for babies.

Do infrared panels emit EMF (Electromagnetic Fields)?

Components of electric power, showing direction, wavelength and magnetic fieldAlthough the Infrared is generated electrically, all Herschel Infrared panels are also tested during certification and certified as “Low Electrosmog” appliances, falling within the lowest category of EMF output . They are also certified as having no radio interference or interference with other control devices (like remote controls) that use IR.

All electronic devices emit electro-magnetic fields in varying levels and collectively this effect is referred-to as “Electrosmog”.

All devices are therefore also subject to regulations governing the amount of acceptable EMF they can produce and reputable manufacturers in Europe are required to adhere to those regulations as part of their CE declaration.

Herschel products operate well within current safety guidelines and standards relating to EMF.

Herschel is also satisfied these standards are regularly scrutinised and updated in light of new research findings in developing technologies, best practice in the industry and legal requirements of health and safety.

Are Infrared Panels Safe to touch?

There is a risk of injury from touching any form of heater and Herschel infrared panels are no different. However, a key benefit of Herschel panels, unlike conventional heaters, is that they can be mounted higher up on walls or ceilings – reducing the likelihood of accidentally touching them or falling against them. We always advise this, especially in areas where young children or the elderly are present.

Our Herschel Inspire panel heaters (excluding our Herschel IR space heating range; Advantage IRP4, Aspect XL etc) have surface temperatures of 185 – 203 degrees Fahrenheit. If you do touch one of these panels you will perceive this as hot on initial contact but, provided you do not continue to touch the panel, are unlikely to scald or burn.

The reason that you can touch Herschel panels without immediately injuring yourself is because a Herschel infrared panel typically has a heat energy or “watt density” of 0.58 watts per inch² – an energy level that the skin can absorb and conduct away from the area of contact.

It is not the temperature that does the damage but the heat energy in the object.

A kettle, for example, typically has a watt density of between 95 – 195 watts per inch². The skin cannot absorb and conduct away this level of energy and consequently scalds on the area of contact. Yet, both the Herschel IR panel and the kettle are close to 210°F.

Warning: Please note that prolonged contact with any heater, Herschel included, will result in injury. Please also note that the Herschel IR space heating range (Advantage IRP4, Aspect XL etc) all utilise elements which run at far higher temperatures and would cause immediate injury if touched. These heaters must always be mounted in accordance with our instructions & never be touched when switched on or for 30 minutes after use.

How long do infrared heaters last?

Herschel Infrared panels come with a 10 year guarantee. Our Inspire range is designed to last decades because of the high quality of materials and advanced heating elements that are used. Herschel Far Infrared panel heaters require no maintenance or servicing. Our heaters use solid state elements unlike water-based heating or fan-assisted systems, which often require servicing, inspection and repair costs. And unlike gas or oil boilers you won’t have to contemplate performing an entire re-installation every 10 years.

Herschel Infrared heaters and control products are certified to national safety standards.

How to control an infrared heating panel?

In order to emit far infrared at the right waveband, our heaters are either “on” or “off” (it is not possible to vary the temperature of the heater itself). So some kind of controller is needed with your infrared panel.

We do not build thermostats into our heaters because it is the temperature of the room that is important to your sense of comfort. Built in thermostats tend to over-read the heater temperature and under-read room temperature because the close proximity of the thermostat to the heater means that it is impossible to correctly measure the room temperature. So we do not believe built-in controls are so effective plus using built in controls leaves little choice for integration into other control systems and whole building control systems.

Herschel offers the Herschel iQ controls system for Inspire panels; heater control solutions especially designed to control Herschel Infrared heaters. Precise room by room control from wherever you are, providing you with optimum comfort levels whilst minimising your energy consumption.

Herschel control systems conform to the EU Eco Design Legislation (also known as LOT 20), granting you up to 8% more efficiency.

Why is infrared heating ideal for hot yoga?

Herschel infrared heaters enable a hot yoga experience that takes you back to its origins, where yoga was performed in the warmth of the summer sun. The therapeutic radiant heat of the hot summer sun directly warms your body, and not the air around you, helping to loosen muscles, resulting in greater flexibility.

Herschel’s Summit 2600 heater is specifically designed to enhance this further with its specialized infrared output, with zero light emitted. Utilizing the latest Kanthal AF heating elements and finished with a white ceramic coating, the Summit can reach temperatures of up to 113°F when specified correctly for your space, enabling you to create an ideal environment for hot yoga. The Summit is manufactured to commercial standards allowing it to be used in both large commercial studios as well as from the comfort of your home with the simple Herschel hot yoga packages.

For home hot yoga studios up to 210ft² you can choose from our three hot yoga packages available in Black or White and compliment any setting. Each package comes with our MD2 mains-powered (WiFi) thermostat allowing for simple manual controls or smart weekly programming.

For commercial hot yoga using our radiant heaters, we recommend contacting us via [email protected] for a complimentary heating survey and quote.

Which outdoor infrared patio heater is best for me?

Outdoor heaters are becoming increasingly popular, but there are many different types of heater available and lots of jargon.

Even on the nicest of days it can often get chilly or cold in the evening and if you want to enjoy socialising outside, outdoor heating is a must.

So we’ve put this handy guide together to help you chose the right heater for you and answer the most commonly asked questions.

Herschel’s guide to outdoor heating