Does 'professional' system need air-vent?

[fittoburst]

Hi

Does anyone know if a system with a pumping station need to have an air vent?  Say the Navitron S1 pumping Station?  Surely the charging/filling unit/machine will pump the fluid round sufficiently into its reservoir to be able to extract all the air.

/fitto

[Amy]

Air will continue to separate from the water as water heats up so you need to be able to eliminate it for some time after initial instalation

[fittoburst]

Thanks Amy

So, what's the best method of putting an air vent on the roof by the panel? I can't use any Navivents or internal vents as the ceiling follows the roof line and once my pipes are in, the ceiling will be plaster-boarded/plastered over and the only access points will be at the pumping station/cylinder or outside on the roof?

fitto

[dimengineer]

It looks like your only option is externally on the roof. The air vent has to be at the high point!
What you may need to do is to tee in your air vent connection at the high point and then bring the vent line down to a suitable point where you can fit your bleed valve in an accessible location

Tim

[fittoburst]

Thanks for the help.

Fitto

[Quakered]

Could use this autovent products. They work really wonderfully on radiators and understand they have been used on solar heating panels as well.

http://www.nlbengineering.co.uk/

[KLD]

From their web page:
"Technical Specification

Operating Pressure Range                  0-10 bar
Operating Temp. Range                       up to 120 deg. C"

If you fit one near the panel (the usual high-point of the system), they might see much higher temps during stagnation.

Klaus

[Jonathan]

The air vent has to be at the high point!

I know this is what is advised, it obviously makes sense to have the vent at the high point. But in my own system I've found that this is not necessary. After the initial fill and flush through with a pressure system - in my case an adapted garden sprayer, there is very little air left in the system, not enough to cause an air lock. The circulation pump is happy to push the air around the system. Each time the pump stops, air will rise to the local high spots, and if the pump starts again, it carries on pushing the air around the system.
Thus I have a manual air vent at the top of the solar coil into the tank, for the first few days after a fill, I can keep letting out the accumalated air, after a while no more appears.

I would say putting the vent at the pumping station, with a short vertical pipe to collect air, will work fine.
regards Jonathan

P.S. I have found that the solar pump does not have enough oomph to do the initial fill.

[Brandon]

as a matter of course I use he S2 pump stations, as they have an air trap built in, hey are a wee bit dearer, but worth every penny in my mind, I used to do all my installs with separate components, and made my own air traps, they worked very well, and could be located in a convenient location.

[greentangerine]

My pumping station has a built in air trap and I also installed one on the manifold on the roof. 

After commisioning it last year, I bled it at the station occasionally over the next month or so.  When I went to bleed the roof vent after about two months of operation, there was more or less nothing that came out.

I'm planning to remove the roof vent when I extend my system with another 15 tubes later this month - it's not required in my system and is another source of heat loss.

[fittoburst]

All...thanks for the info.

Interesting. It sounds like an upper vent is not necessarily required as the pump will push the air round and it could be caught elsewhere? 

How do the air-traps work on the pumping stations? Do they still need manual bleeding, or are they automated?

Thanks

Fitto.

[greentangerine]

Mine collects the air and you just bleed it occasionally with a little key type thing. 

Actually did it for the first time in months the other day and no air in there.

I have a a Steca TPS20 pump station.

[pdf27]

as a matter of course I use he S2 pump stations, as they have an air trap built in, hey are a wee bit dearer, but worth every penny in my mind, I used to do all my installs with separate components, and made my own air traps, they worked very well, and could be located in a convenient location.

Just to check, if a pump station has an air trap in it there is no requirement for an additional air trap at the top of the system?

[baker]

its all down to the material/  and component's used
in the system
compression fittings
standard expansion /diaphram ect

baker

[wookey]

pdf27, it would appear not, but you will also need a reasonably high-power pump fill to get the system initially filled if you have no top-bleed. This can be done with a drill-pump as well as a fancy solar-installer type pump (£400-odd). See http://www.greenbuildingforum.co.uk/newforum/comments.php?DiscussionID=8474&page=1#Item_19 for practical example.