# How TRVs actually work?

That confused me till I realised your sq root only applies to (1.0/0.3), not 7.1*60/1000. But shouldn't it be 7.2?
Presumably the 0.3 bar is the pressure drop across the TRV (not sure what you mean by dynamic head, that's usually V^2/(2*g))

Not with you. If it's 1.2 each isn't that 2.4m? Earlier you said 3m = 0.3 bar across the TRV, unless I'm misunderstanding you test.
BTW, TVR is (or was) a sports car
No, I will correct this, it was 7.1LPM at 0.3bar. What I mean by the dynamic head is the head available at the TVR when flowing 7.1LPM, with no flow, the head, which I call the static head was 0.55M. The dP through the TRV at a flowrate of 1.43LPM should be (1.43/7.1)squared x 3M, 0.12m, TRV+L/S, 0.24M, not 0.44M (will edit above post).

The Heat Geek knows best??.

View attachment 326135

Balancing heating systems is simply making sure all the radiators or emitters heat up evenly

At least we have someone putting forth a basis!

It's a start.
But it's wrong.

It makes huge assumptions.

What you actually want is rooms heating up as quickly as possible in a system which is as stable as possible.
Quite difficult to do. Nothing to do with making the rads heat up in sync with the lowest common denominator.

For the post i was referring to,
Modern pumps are absolutely not designed to provide a constant head in a normal system (CP). They are PP pumps designed to provide variable flow to reduce energy consumption.

Dunno wtf 11-12c temp drop is relevant? I doubt the poster couldn't explain either.

Etc.etc.

Everything just missed the point.

I will do my own calcs later.

Dunno wtf 11-12c temp drop is relevant? I doubt the poster couldn't explain either.
Without a delta T on the rad, the Rad is not delivering any energy to the room...

The greater the dT for any given flow temperature the lower the rad output.
A normally rated T50 rad will emit 100% output with flow/return temps of 75C/65C, dT,10C. (assumes 20C rom temperature)
A normally rated T50 rad will emit 87.2% output with flow/return temps of 75C/55C, dT,20C. (assumes 20C rom temperature)
With a low flow temperature from a Heat Pump or from a WC Boiler the dT is kept as low as possible to get the maximum possible output.
The rad above will emit 25.5% of rated output with flow/return temps of 40C/35C, dT,5C.
It will only emit 20.9% of rated output at flow/return temps of 40C/30C, dT,10C, or 82% of the 5C dT rad.

Without a delta T on the rad, the Rad is not delivering any energy to the room...
The value.

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