Pipe run from boiler to UFH manifold is specified by UFH folks as 28mm
so 28mm fittings on manifold, but current run is in 22mm.

Were I to bother to replace the 8' run in 28mm, would there be
significant benefit as I'd have to replace 3 nicely radiused bends (both
f+R) with 28mm 90 degrees.
i.e. would solder 90's on 28mm still make for significantly greater flow
than radi'd 22 mm (both F + R)

(The run essentially round 3 sides of base of old chimney stack in
airing cuppoard.)

Persdonally I'm thinking towards just 28mm from Manifold to existing 22mm.

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"Pet @ www.gymratz.co.uk" wrote in message
k...
Pipe run from boiler to UFH manifold is specified by UFH folks as 28mm
so 28mm fittings on manifold, but current run is in 22mm.

Were I to bother to replace the 8' run in 28mm, would there be
significant benefit as I'd have to replace 3 nicely radiused bends (both
f+R) with 28mm 90 degrees.
i.e. would solder 90's on 28mm still make for significantly greater flow
than radi'd 22 mm (both F + R)

(The run essentially round 3 sides of base of old chimney stack in
airing cuppoard.)

Persdonally I'm thinking towards just 28mm from Manifold to existing 22mm.

What is the heat output of the UF ? I've just had to change a 22mm system
to 28mm but that was for a 40m send and another 40m back carrying 20kW.

Mike wrote:

Persdonally I'm thinking towards just 28mm from Manifold to existing 22mm.
What is the heat output of the UF ? I've just had to change a 22mm system
to 28mm but that was for a 40m send and another 40m back carrying 20kW.

10kW UFH load feeding all of living floor (4 zones) but this then shared
(T'd off) to Bedroom/Bathroom floor zone which is 6 rad's in total all
run in 15mm from original heating config. All routed from airing cupboard.

Re-running from boiler to airing cupboard all in 28mm (replacing
existing 22mm isn't a huge problem). And there is a posibillity of
upgrading HW to one of them Pandora Heat bank things also in the airing
cupoard, but that might be a job for the future.


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http://trade-price-supplements.co.uk - TRADE PRICED SUPPLEMENTS for ALL!
http://fitness-equipment-uk.com - UK's No.1 Fitness Equipment Suppliers.
http://gymratz.co.uk/hot-seat.htm - Live web-cam! (sometimes)

"Pet @ www.gymratz.co.uk" wrote in message
k...
Mike wrote:

Persdonally I'm thinking towards just 28mm from Manifold to existing
22mm.
What is the heat output of the UF ? I've just had to change a 22mm
system
to 28mm but that was for a 40m send and another 40m back carrying 20kW.

10kW UFH load feeding all of living floor (4 zones) but this then shared
(T'd off) to Bedroom/Bathroom floor zone which is 6 rad's in total all
run in 15mm from original heating config. All routed from airing cupboard.

Looking at the Copper Development Association tables I'd say 22mm was okay
in your case provided there aren't lots of joins or bends in it, though you
had better look at them yourself to confirm all the details.