Pics of 50x58mm install - help needed

[50 tuba]

Hello everyone,

We've just finished the install of our 50 x 58mm tube system but we've come up against an unexpected problem.  Our kit is recent enough to have the new screwcap tube retainers.  I thought these would be great as they're much easier to use than rubber boots and jubilee clips.  However, the problem is that;

1. The tubes all vary in length (is this normal?) and so I've had to tighten some of the screwcaps almost to the limits of their threads.  Is this okay? and if not, what should I do instead?

2.  The screwcap rings are quite loose in the aluminium bottom rail and can pop out unless they're under pressure.  The only way to achieve that pressure is to tighten the screwcaps until they're firmly finger tight.  Again, is this okay or should I be doing something else.

At the end of the day, I'm worried about the tubes coming loose or being blown off the roof by the wind if the retaining caps give way.  For this reason, I've decided not to fit the reflectors.  the only bodge I can think of if the screwcaps aren't robust enough is to dab silicone onto the threads as a 'threadlock' and into the bases to stop them coming out of the aluminium bottom rail.

Apologies for the basic questions - I'd put a call into Navitron themselves but the scaffolding comes down tomorrow so I need advice now!

I've also posted a pic showing the manifold connection we've used.  Our plumber fabricated the lead hood and slate with pipe through it.  I'm hoping that it'll be more robust than the drill through and silicone method.


Thanks for your help,

50 tuba

[dhaslam]

I have the olter clip type plus I didn't self install but looking at the your photograph the tubes do seem out of line and I don't think the tubes vary in length.   Are you sure they are fully inserted at the top?   

[GaryTwigg]

Hello 50 tuba

I agree with dhaslam, I dont think your tubes are pushed all the way in.

Try taking the apparently longest & shortest tubes out of the manifold & compare the lengths side by side & I think they will be the same.

I was surprised at how hard I had to push dome of the tubes in on my 60 X 47mm system

Best Regards

SolarNewbie

[50 tuba]

Thanks for the replies and PM I've had so far.  The consensus is that the tubes are all the same length so the rather wavy line of tubes is down to my incompetence at fitting them!  I did check when the tubes went in that they were fully home (no clear glass at the top of the tube) but it's clear now that I wasn't applying enough pressure.

Thanks again,

50 tuba

[pracrichard]

I too had considerable difficulty getting the tubes pushed fully 'home' I found that some would only go in so far but when I went back to them later they went further in quite easily. No trouble with the end caps 'though. Mine were a nice tight fit.

Richard

[GaryTwigg]

Hello everyone,


2.  The screwcap rings are quite loose in the aluminium bottom rail and can pop out unless they're under pressure.  The only way to achieve that pressure is to tighten the screwcaps until they're firmly finger tight.  Again, is this okay or should I be doing something else.

At the end of the day, I'm worried about the tubes coming loose or being blown off the roof by the wind if the retaining caps give way.  For this reason, I've decided not to fit the reflectors.  the only bodge I can think of if the screwcaps aren't robust enough is to dab silicone onto the threads as a 'threadlock' and into the bases to stop them coming out of the aluminium bottom rail.


50 tuba

Hello Again

I would put the reflectors in if it's not too late.  I was worried about the tubes in my 47mm system coming loose, but we have had a couple of serious gales recently and although one tube has been broken, it was caused by a blow from low flying garden chair that had not been put away.  The tube, although clearly broken, is still held in place by the end cap.

SolarNewbie

[KLD]

50Tuba
I've just put two 20x47mm panels up, and also found that some tubes go in easier than other. Somebody here suggested to run a file in the manifold ports, and wipe a slip of sandpaper around each tube end. Doing this I found a few small nibs and dings. Also, the heat pipes are made of quite soft copper, so the ends of the pipes aren't necessarily aligned with the rest of the tube. Twisting and wobbling the the tube slightly seemed to help more then pushing harder 
Also, a cloudy day helps, since the heatpipe ends seem to swell a little when they get hot.

Your pipes through the lead hoods seem to enter the roof more or less horizontally. How did you solve the venting / air lock problem?

Yep, know the feeling of the scaffolding people taking out the first planks while you're still pushing in tubes

Best of luck
Klaus

[50 tuba]

KLD,

Thanks for the tips - as you can see from the photos, the day was anything but cloudy so that may have had a bearing on why I've struggled!

The friction seemed worst at the point where the glass tube met the rubber boot.  I just wetted the glass and pushed it in with a twisting movement once the copper bulb was lined up in the manifold.  I also had a couple of manifold ports which were out of alignment with the bulb sockets - in the end, I had to remove the rubber boots from the port, place it over the tube and then re-insert, boot and all.

I'll let you know how I solve the venting/air lock problem once I've finished bleeding the system 

In theory... the horizontal pipe terminates in a tee-piece.  There is a ball valve and rad valve on the upward facing branch of the tee, the lower branch is flow or return as this arrangement has been put in at both ends of the manifold.  Sounds good in theory...

... In practice... I struggled to get the system to circulate yesterday until I bled some of the glycol mix at the thermal store which cleared an air lock and got the flow from the manifold to the store working (or so I thought).  Today, we had a decent amount of sun and the system appeared to be working for a while, but a climbing manifold temp and only slowly increasing store temp had me worried.  The flow to the store was hot but the return was cold.  What's more, the return was pretty warm in the attic as well - so it appeared that the manifold was stagnating.  Sure enough, cracking the bleed valves got me a whole load of steam out of the manifold flow which allowed more glycol mix into the manifold - and then the sun went in... but I got the manifold temp reading down from 77c to about 55c in the time it took me to get out of the attic.  There is clearly an art to bleeding these systems - I guess the use of long runs of 10mm pipe (approx 25m in total) doesn't make it any easier.

So far, even with my incompetence over the last 2 days, the top of store temp has risen from 32c to 45c.  (It's an Akvaterm solar 500 with a notional 500 litre capacity but it's baffled to split 300 litres solar, 200 litres direct heat).

Off to re-pressurise and re-bleed...

50 tuba

[StBarnabas]

Hi 50 yuba
do I also see a sun pipe on your roof? Would you recommend them?
Stb

[50 tuba]

Stb,

You do indeed see a sun pipe on the roof and yes, I would recommend the one we have (no experience of others but chose this one after some careful research).

It's the Solatube 290DS model.  Our builders have experience of the smaller ones from other manufacturers and they were sufficiently impressed with this one to comment on it.  I suspect that size is important, so regardless of manufacturer, plump for the biggest one you can.

The sun pipe is south facing and it feels like it introduces as much light into the windowless ensuite as the bedroom next door gets with its east facing windows.  I should get a light meter out to check but we've been so pleased with it, I haven't bothered!

50 tuba

[StBarnabas]

Thanks
Tuba (rather than Yuba) clearly need more light on my keyboard! Your roof construction - slate seems similar to mine. What did you use to drill through your slates? I already have a water system in but am about to embark on a 3kWp PV build so need to decide how I am going to mount the panels.
StB

[50 tuba]

StB,

The slates were removed and the standard Navitron fixing method of stainless steel strapping fixed to the frame and passed under the slates was used.  This was complicated by the fact that this section of roof is sarked so the sarking was cut away where the straps needed to fit through the roof.  Noggins were then added to the underside of the sarking strengthen the cut edge and the steel strapping was screwed to the noggins.

50 tuba