Re: multi-zone central heating

[Kevin Hawkins <lists@xxxxxxxxxxxxxxxxx>]

Does anyone know of a reasonable cost 'proportional' valve in this
format (attach to radiator)  - one where say 0-10V will provide linear
control from closed to open ? Or failing that where a timed application
of a voltage will open a valve a certain degree and it will stay there.

Kevin

Neil Ball wrote:

>These type of actuators are commonly found on underfloor heating
manifolds.
>They do take a while to open & close which is not a problem with
UFH due to
>it's relatively slow thermal response. Biggest benefit is ease of
wiring and
>low cost compared to motor-based actuators. If you are thinking of
using
>them on radiator TRV valve bodies just make sure you get the right
torque
>rating as too high a closing force will damage the soft valve seats
very
>quickly and stop the valve from shutting off.
>
>Neil B.
>-----Original Message-----
>From: William Sadler [mailto:ukhad@xxxxxxx]
>Sent: Thursday, January 20, 2005 17:43
>To: ukha_d@xxxxxxx
>Subject: Re: [ukha_d] multi-zone central heating
>
>
>
>On the same theme, has any body used these: Thermo-Hydraulic
>Actuators?
>
><http://www.danfoss-randall.co.uk/Site/downloads/VDSAP112.pdf>
>
>Which from the online page can be used to replace thermostatic
>radiator valve heads and controlled electrically with 230 or 24
>volts.
>
>William.
>
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