Energy emitted by radiation from a pipe

[Karol]

Homework Statement

A vertical steam pipe of diameter 8 cm and emissivity e=0.8 has it's surface at 95⁰C. The surrounding air and the temperature of the room and things in it are at 27⁰C.
What is the heat emission rate H from the pipe, for meter length, by radiation?

Homework Equations

Stefan's law: $R=e\sigma T^4$
$$\sigma=5.672\times 10^{-8}\left[Watt/m^2\right]$$
$$1\left[Calorie\right]=4.186\left[Joule\right]$$

The Attempt at a Solution

$$R=0.8\cdot 5.672\times10^{-8}\left(373^4-300^4\right)=511\left[Watt/m^2\right]$$
$$H=511\cdot \pi \cdot 0.08\cdot 1=128\left[Watt/m\right]$$
$$128\left[Watt\right]\div 4.186=30.6\left[Calorie/Sec/m\right]$$
The answer, according to the book, is $29\left[Calorie/Sec/m\right]$

 

[JaWiB]

95C is ~368K not 373K, though using 368K I get only 28 cal/s/m

 

[Karol]

The book uses Kelvin as Celsius+273