Help with charge calcs

[dallan]

Can anyone help with calculating the refrigerant charge for various pipe sizes.

Initially I thought I knew the procedure when trying to calculate the kg amount for a 1 metre run of 1/2 liquid line (R404a), however my answer indicates I went wrong somewere along the line.

[Peter_1]

Why do you need to calculate this Dallan?
I should say, calculate the inner volume and multiply it with the specific mass of the refrigerant at the conditions it passes through the lines.
But this has nothing to do with refrigeration, this is math.

[dallan]

Thanks for the reply Peter.

I want to establish a guide per metre of pipe to make ordering refrigerant for larger projects more accurate.

The main problem is my math is apparently awful.

What I was looking for was a breakdown of the math steps to see were I am going wrong.

Thanks

[dallan]

When calculating my charge I am using the density for the relevant refrigerant, for R404a this is around 1000kg/m3. Is this correct.

[Peter_1]

Indeed correct at +/- 23°C for R404a.
1,01 dm³/kg at 25
You can find these numbers with Coolpack.