ELV (12 volt DC ) operated zone valves

[bernardgreen]

could you not repipe the rads to a central manifold below the roofline and control from there?

With beams and joists that should not ( or must not ) be drilled ( grade II listed building ) getting a single pair of flow and return to the rooms is difficult enough.

The choice is between efficient simplicity off the shelf, or an impressive array of gizmos.

Off the shelf is not always simpilicity if the equipment has to be "stretched in function" to meet the requirement. And how many off the shelf items have impressive gizmos to make them look impressive like glow in the dark touch panels.

 

[looneyfitter]

The choice is between efficient simplicity off the shelf, or an impressive array of gizmos.

Off the shelf is not always simpilicity if the equipment has to be "stretched in function" to meet the requirement. And how many off the shelf items have impressive gizmos to make them look impressive like glow in the dark touch panels.[/quote]

The heatmiser stuff is all LV and back lit. You could use 24vdc uponor actuators at each radiator, then it's just a cas Lenox low voltage cables to each rad and a 240-24v transformer and a relay for each rad at a central point. Job done.

 

[mysteryman]

Glow in the dark touch panels, back lit? = gizmos.

Keep the requirements simple, invest in weather comp and get the further fuel economy.

 

[Onetap]

Also known as highly non-linear , large reductions in water flow rate results in only a small reduction in heat output rate only becoming more linear as design flow & return temperature differential is increased.

Only if you assume the heating flow temperature is fixed; which it wouldn't be. WC or controlled to keep the maximum terminal valve demand around the 90% region.

 

[Norcon]

Trvs are also very slow to react!!

There are two commonly known sensor types. Wax and liquid.
Liquid is generally considered to be faster reacting than wax.
Some industrial type valves are gas filled. Like the Danfoss avta cooling valves.

The only gas filled trv I know off is the Danfoss RA sensors which are filled with a saturated vapour charge. Danfoss claim they are a lot faster than liquid which has obvious benefits and having installed avta valves I know their temperature adjustment is virtually instant and would expect the RA sensor to be similar.

I expect the OP has had cheap wax filled trv sensors fitted which Danfoss refer to as "Old-fashioned technology".

 

[looneyfitter]

Fair play with the Vapor trvs etc but as you say, prob has the wax filled type. You still can't beat the control the "gizmo's" give tho.

Individual programmable,temp control of each room with optimisation. Then also being able to control it all over the web/iPhone/desktop etc and a central pad. Also makes for easy holiday programming too each to there own I suppose

 

[bernardgreen]

I expect the OP has had cheap wax filled trv sensors fitted which Danfoss refer to as "Old-fashioned technology".

Nothing at all fitted as there is no system in the cottage until I install it. But I am well aware of that type of TRV sensor. I do not like TRVs, I see them as a cheap as in minimum effort method to "control" the temperature in a room.

 

[looneyfitter]

I expect the OP has had cheap wax filled trv sensors fitted which Danfoss refer to as "Old-fashioned technology".

Nothing at all fitted as there is no system in the cottage until I install it. But I am well aware of that type of TRV sensor. I do not like TRVs, I see them as a cheap as in minimum effort method to "control" the temperature in a room.

If there is no system fitted as yet, then why can't you get all pipework back to a central point for control?

Can you not hide the pipework in a box skirting with drops from the loft for example? Minimal drilling

 

[bernardgreen]

Can you not hide the pipework in a box skirting with drops from the loft for example? Minimal drilling

This is a Grade II listed building being renovated and modernised while maintaining as much of the original fabric and appearance as possible. Drops of pipe work down from the loft area are not acceptable. They look bad in a modern house. In an old cottage they look very bad.

If there is no system fitted as yet, then why can't you get all pipework back to a central point for control?

One 22mm flow, one 22mm return and one ELV multicore cable take up far less notch or drilled space in a 400 year old joist than one 22mm return and five 15mm controlled flows.

Working in the loft is prone to difficulty as the structure is strong enough to support the ceiling but un-likely to be safe to support a person's weight.

My question was about low voltage motorised valves, not how to design the system.

 

[looneyfitter]

You've asked for a motorised valve that isn't standard/costly. Just trying to give you other options.

The 24vdc one I suggested would do the job from what I can see. How high are the ceilings? Could you raise the floor 25mm?

 

[bernardgreen]

9 years later...........

With a few years experience of living in the cottage an update,

The control system has been simplified based on that experience.

The doors upstairs are original ( ancient ) cottage style which allows warmth from downstairs to get to all the rooms upstairs. Other than in very cold weather one radiator in the dining room at the bottom of the open plan stairs keeps bedrooms and bath room comfortable warm.

It has been reduced to be 24 volt wax valves on three radiators ( bedrooms and lounge ) and my "home made" 12 volt actuators on the two hot water cylinders and one radiator ( dining room ).

Originally the plan was to have motorised actuators on all radiators but wax operated valves are more convenient in terms of size and silent
operation.

.

 

[Gasguru]

Did you salvage the large gear from an existing actuator or are you a 3D printer?
Magnets embedded in the gear wheel activating reeds?
Is this a paddle or shoe valve...if the former how are you pre-loading the paddle to ensure full shut-off...normally that would be done by a couple of springs.

 

[bernardgreen]

Large gear is a stock item and then machined to fit the shaft on the valve, 90 tooth Mod 0.8

Yes magnets activating reed switches, the IC is a ULN 2803 ( 8 darlington drivers )

Not a paddle valve but a ball (?) valve, only rotates in one direction.