The image above represents radiosity.

To compute for radiosity, three essential parameters are needed and these parameters are **Total Emissive Power (e), Reflectivity (ρ)** and **Total Irradiation (G).**

The formula for calculating radiosity:

J = e + ρG

Where:

J = Radiation Heat Transfer

e = Total Emissive Power

ρ = Reflectivity

G = Total Irradiation

Let’s solve an example;

Find the radiation heat transfer when the total emissive power is 12, the reflectivity is 10 and the total irradiation is 20.

This implies that;

e = Total Emissive Power = 12

ρ = Reflectivity = 10

G = Total Irradiation = 20

J = e + ρG

J = 12 + (10)(20)

J = 12 + 200

J = 212

Therefore, the **radiosity **is **212 W/m².**

**Calculating the Total Emissive Power when the Radiosity, the Reflectivity and the Total Irradiation is Given.**

e = J – ρG

Where:

e = Total Emissive Power

J = Radiation Heat Transfer

ρ = Reflectivity

G = Total Irradiation

Let’s solve an example;

Find the total emissive power when the radiation heat transfer is 32, the reflectivity is 10 and the total irradiation is 2.

This implies that;

J = Radiation Heat Transfer = 32

ρ = Reflectivity = 10

G = Total Irradiation = 2

e = J – ρG

e = 32 – (10)(2)

e = 32 – 20

e = 12

Therefore, the **total emissive power **is **12.**

**Calculating the Reflectivity when the Radiosity, the Total Emissive Power and the Total Irradiation is Given.**

ρ = ^{J – e} / _{G}

Where:

ρ = Reflectivity

J = Radiation Heat Transfer

e = Total Emissive Power

G = Total Irradiation

Let’s solve an example;

Find the reflectivity when the radiation heat transfer is 28, the total emissive power is 10 and the total irradiation is 4.

This implies that;

J = Radiation Heat Transfer = 28

e = Total Emissive Power = 10

G = Total Irradiation = 4

ρ = ^{J – e} / _{G}

ρ = ^{28 – 10} / _{4}

ρ = ^{18} / _{4}

ρ = 4.5

Therefore, the **reflectivity **is **4.5.**

**Calculating the Total Irradiation when the Radiosity, the Total Emissive Power and the Reflectivity is Given.**

G = ^{J – e} / _{ρ}

Where:

G = Total Irradiation

J = Radiation Heat Transfer

e = Total Emissive Power

ρ = Reflectivity

Let’s solve an example;

Find the total irradiation when the radiation heat transfer is 44, the total emissive power is 14 and the reflectivity is 2.

This implies that;

J = Radiation Heat Transfer = 44

e = Total Emissive Power = 14

ρ = Reflectivity = 2

G = ^{J – e} / _{ρ}

G = ^{44 – 14} / _{2}

G = ^{30} / _{2}

G = 15

Therefore, the** total irradiation **is **15.**

Nickzom Calculator – **The Calculator Encyclopedia** is capable of calculating the radiosity.

To get the answer and workings of the radiosity using the **Nickzom Calculator – The Calculator Encyclopedia. **First, you need to obtain the app.

You can get this app via any of these means:

**Web** – https://www.nickzom.org/calculator-plus

To get access to the **professional **version via web, you need to **register** and **subscribe **for** NGN 2,000 **per** annum** to have utter access to all functionalities.

You can also try the **demo **version via https://www.nickzom.org/calculator

**Android (Paid)** – https://play.google.com/store/apps/details?id=org.nickzom.nickzomcalculator

**Android (Free)** – https://play.google.com/store/apps/details?id=com.nickzom.nickzomcalculator

**Apple (Paid)** – https://itunes.apple.com/us/app/nickzom-calculator/id1331162702?mt=8

Once, you have obtained the calculator encyclopedia app, proceed to the **Calculator Map, **then click on **Materials and Metallurgical **under **Engineering****.**

Now, Click on **Radiation Heat Transfer **under **Materials and Metallurgical**

Now, Click on **Radiosity **under **Radiation Heat Transfer**

The screenshot below displays the page or activity to enter your values, to get the answer for the radiosity according to the respective parameter which is the **Total Emissive Power (e), Reflectivity (ρ)** and **Total Irradiation (G).**

Now, enter the values appropriately and accordingly for the parameters as required by the **Total Emissive Power (e)** is **12**,** Reflectivity (ρ) **is **10** and **Total Irradiation (G)** is **20**.

Finally, Click on Calculate

As you can see from the screenshot above, **Nickzom Calculator**– The Calculator Encyclopedia solves for the radiosity and presents the formula, workings and steps too.