BTU's at delta T65 and T50

Discuss BTU's at delta T65 and T50 in the Plumbing Forum | Plumbing Advice area at PlumbersForums.net

pacarter11

Hi Guys,
Need some help. I have calculated online the BTUs for the rads (calculator used T65) then when purchasing I was looking at the T65 radiator calculations...
But I have since noticed, Europe uses T50 as standard. What calculation would I use to convert the T65 BTU needed to the new T50 (I presume I would need to increase the number).

Or would it stay the same and I would just need to choose rad BTU's at T50?

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ShaunCorbs

S. Mod
Plumber
Gas Engineer
Flow plus return temp

Divide by two

Minus your room temp

Eg

65+50

115/2

57.5

Mins let’s say 18

Gives you a delta t of 39.5

Delta t of 50 you would need your flow and return around 75-65

Which if you have a condensing boiler is bad

TBH I would work off a delta t of 40

John.g

Hi Guys,
Need some help. I have calculated online the BTUs for the rads (calculator used T65) then when purchasing I was looking at the T65 radiator calculations...
But I have since noticed, Europe uses T50 as standard. What calculation would I use to convert the T65 BTU needed to the new T50 (I presume I would need to increase the number).

Or would it stay the same and I would just need to choose rad BTU's at T50?
Output of a 50 deg rad is (50/60)^1.3. I , can't work this out in my present location but very easily done on a spreadsheet . You can also and easier look it up in a radiator temperature correction table.

John.g

Hi Guys,
Need some help. I have calculated online the BTUs for the rads (calculator used T65) then when purchasing I was looking at the T65 radiator calculations...
But I have since noticed, Europe uses T50 as standard. What calculation would I use to convert the T65 BTU needed to the new T50 (I presume I would need to increase the number).

Or would it stay the same and I would just need to choose rad BTU's at T50?
Slightly misread your post so if the calculation was based @ T65 then the correction factor to run @T50 is 1.41, (65/50)^1.3.
IF it had been based @T60 then the correction factor to run @T50 is 1.27, (60/50)^1.3.

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