Radiant Heater Calculator

Introduction to the Radiant Heater Calculator

By choosing to use our radiant heater calculator you will have already appreciated the difference between space heating and radiant heating. If you have any doubt about this please look at this page here that explains all. Before you look for a radiant heater solution it is well worth understanding how much radiant heat your building needs. This is where our Radiant Heater Calculator comes in useful.

Our Radiant Heater Calculator Tool is aimed at commercial and industrial type spaces rather than for domestic applications. It does not require the level of detail that is required for heat loss calculations (i.e. u-values, window sizes etc. ) but it is simple enough to estimate of how much radiant heating you need. For the vast majority of applications it is capable of establishing your radiant heater requirements.

radiant heater calculator

Notes about the inputs for the Radiant Heater Calculator

The radiant heater calculator requires two inputs - length and width.

This is simple enough if you have a rectangular room. If however your floor plan is more complex you might want to split it into a number of rectangles and treat each in turn. Alternatively, you could work out the overall floor area of the room in m2. Then put the square root of the area into the width and length box on the calculator.

Understanding the results from the Radiant Heater Calculator

The results window offers an array of application types each with the recommended range of radiant heater capacity needed.

Radiant heater calculator results

Ultimately the radiant heater calculator has some a number of heating factors based on watts per m2 of floor area that are applied to the application and multiplied through the floor area to deliver the results. It is useful to understand some background to these rates.

Buildings in constant use will tend to need less heating capacity than those that are used for occasionally for short durations. With occasional use buildings, such as community halls and churches, a quick warm up time is neeed and therefore greater heating capacity is required. In contrast, offices in constant daytime use can usually sacrifice time of warm up and achieve what they need with less heating power. Also consider if the occupants of the building are to be sedentary or active. For example active environments, such as sports centres and workplaces where there is physical work, will require less heating than offices for example.

Other considerations when using the Radiant Heater Calculator

The radiant heater calculator is enough to get you in the ball park, however, there are further considerations.

• What type of radiant heaters?

• What will be powering them - electricity (230v or 415v), gas, oil, hot water, steam ...?

• How many?

• What output per heater?

• How should they be mounted - wall mounted, free standing, ceiling recessed, roof hung?

• What is the ideal height?

• How should they be controlled?

There are other helpful pages and calculator tools on this site that can help you answer these questions. But sometimes it is simpler to just ask us by phone or email.

What next?

So you have used the radiant heating calculator and you need some heaters. Call us!

Heat Load	Watts	BTU
Average The Room Is A Normal Residential Room, Office, Reception Area Or Similar, Where There Is Not Overly Crowded With People, Computer And Office Equipment.
Above Average There Are Factors That Contribute To Additional Heat Being Generated In The Room E.G. Strong Lighting, Overcrowding With People And Office Equipment, Conservatory Type Room, Or Flat Roofed Room.
High There Are Factors That Contribute To A High Heat Load In The Room. E.G. Commercial Cooking, Much Computer And Server Equipment, Switchgear, Temporary Building With Thin Walls And Flat Room, Plain Glass Conservatory.

Variable	Units	Notes/Guidance
System Airflow	M3/Hr	If you have it in cfm then multiply your cfm value by 1.7 to get m3/hr
Average Combined Pressure Drop Of Filters Of Higher Than F6 Efficiency	Pascals	F8 bag filters pressure drop - typical clean clean to dirty, 160 - 250 Pascals F9 compact filters pressure drop - typical clean to dirty, 160 - 350 Pascals H10 HEPA filter pressure drop - typical clean to dirty, 250 - 600 Pascals 9.8 Pascals = 1 mm wg, & 249 Pascals = 1 inch wg
Carbon Filters Pressure Drop	Pascals	For compact type carbons pressure drop between 100 - 150 Pa Bonded carbon panels typically 150 - 170 Pa Loose granular carbon panels typically 130 Pa
Annual Operational Hours	Hrs/Annum	8760 hours in a year If operating for 5 days a week, excluding public holidays, for 12 hrs/day = 3000 hrs
Cost Of Power	Pence Per Kwh	Huge variance in what different companies pay. heck your last bill to be sure, otherwise put in 10p
Fan Efficiency	(As Decimal Value, Eg 100%=1)	Would typically be around 60%, so if you don’t have specific information use 0.6
Fan Motor Efficiency	(As Decimal Value, Eg 100%=1)	Larger motors should be around 90%, so if you don’t have specific information use 0.9

The Total Average Pressure Drop Over Your Higher Efficiency Filters And/Or Carbon Filters Is;		Pascals
This Pressure Drop Is Costing In Energy Alone	£	Per year
It Is Probable That A Sanuvox In-Duct System Could Break Down The Biological, Chemical And Odourous Contaminants On This Air Flow For Between 16 And 25% Of This Running Cost	£	Lower energy cost estimate of an equivalent Sanuvox system (16%)
	£	Higher energy cost estimate of an equivalent Sanuvox system (25%)

Type Of Building	Kw Range		BTU Range
Sports Centres
Retail Premises
Office Premises
Small Industrial Unit
Medium Industrial Units
Larger Industrial Buildings
School/Community Halls
Churches

Room/building volume	m3
Temperature differential (deltaT °C)	°C

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Radiant Heater Calculator