It is now approaching two years since I did any real work, except of course for the effort of fixing up our house in Macclesfield just before we left.
I really have missed it as time has passed by, and it is time to start getting back into the world of fixing, changing and making things. Of course we are still very, very keen to get our hands on this elusive house which we are trying to buy but the sellers are still playing hard to get.
We continue to wait.
In the meantime, following a short message exchange on Facebook, I was contacted with a request to swap out the ventilation fans in three bathrooms, the property is fairly nearby so it seemed a good idea. I wasn't expecting to actually get the work as they were asking for a local electrician. The people wanted the basic switched fans replacing with the type that run-on for a time after the lights have been switched off. It is a fairly simple task, or it should be!
Of course, I have fitted and changed fans before.
Typically, the main problem which this specific job presents is that the new fans will need an extra wire to provide a permanent live connection on the fan. Usually this would be taken from the light switch because the main power is always available there. As this is my first time doing such work in a Portuguese built house there was much to investigate before committing to do the work. I visited the house, looked inside the switch boxes, inside the junction points which are present in a box above the light switches. I looked at the existing fan units just to verify that the wiring did not already provide a permanent live conductor, obviously it didn't. But all seemed straightforward, there would be some unknowns when it came to routing the new cable, but conduit is used everywhere through the walls and ceilings so it should be doable.
Schoolboy error 1; even though I had taken down one of the fan units and examined it, and looked at the vent tube in the ceiling, it never occurred to me that I should actually measure the dimensions of the tubing and fan. So, when we agreed on the type of quality fan to use, it was obviously going to be 100mm (4") diameter. I ordered the items, made sure I had sufficient cable to do the task and checked that I still had all of the required tools.
All was good, the new fans arrived and we arranged a day to do the job and I duly turned up as agreed full of expectation for a fun day.
For whatever reason, it was immediately obvious that the old fans were small, definitely smaller than the units I had bought and after removing the fan and measuring the tube anyone could see that the 100mm fan exhaust would not fit inside the 85mm tube. Stumped at the first ball, but undeterred, and assuming that maybe the tube(s) could be replaced, the work carried on, we needed to see how the vent tubing was arranged.
The choice of doing the first fan in the bathroom which had a 400+ mm wide light tunnel which we could apparently 'just take out to see into the ceiling void' was probably not the best choice. The task of removing it took over an hour, though 60% of that time was taken up by head scratching. Eventually there was a big hole to view into the void and we could see that the tubing ran all the way up to a point just under the roof tiles, it was secured with a wire tie that actually passed through the tube - bizarre. With no sensible way to remove the tube and even less chance of securing a new one in place I decided that it wasn't getting done that way. Noting that this was the only ceiling void that offered any type of access, the others would be impossible to work in. We needed a new plan.
The internet was scoured for some time afterwards to source a fan unit of the correct size with a timer module, with no success. Absolutely nothing was available, the existing fan units were located on a Portuguese shop web-site and we determined that they were in fact about the cheapest fan available, hence why they were now rather noisy after just a few years.
The next possible solution was to insert a simple timer module into the circuits, but at this point we had no idea of the wiring arrangements, were the fans wired from one of the lights or directly from the switch. A clue came in the way the conduit had been installed. Two different types, the cable to the light was in smooth tube and to the fan inside corrugated tube, why? Surely not for identification. The reason came when attempting to push the cable draw tape through the corrugated tube, there was obviously a sharp bend a little way into the wall, which even the rounded flexible end on the draw tape would not negotiate with the existing cables installed.
Schoolboy error 2; Don´t try and feed the draw tape or new cable(s) into already populated corrugated conduit tubes, just remove all the existing cable from the conduit instead of trying and failing and failing again.
However, it was proved that the light and fan were wired individually and the mass of connected cables in the junction box was subsequently deciphered. The wiring side of the job would not be as difficult as it first seemed.
A quick examination of the other bathrooms showed that the fan ducting was also impossible to replace without destroying the ceiling. Another plan had to be hatched. After further searching for 85mm diameter fans modules incorporating a timer it became clear that nothing was available. Using a separate timer module would not solve the problem of the noisy fans and not achieve what the customer wants. Thinking of the sizes of the tubes it seemed entirely possible to sleeve the larger pipe in he new kits over the existing one with a gap of approximately 4mm all round, the kit also included some self adhesive foam tape which could be used to create a seal. A brilliant idea that was missing just one thing; a way to cut 120mm or so off the end of the existing vent tube to allow the new fan to fit in place. Once again Google was brought into play and we found exactly the item needed. An internal pipe cutting disc, unfortunately not available anywhere in Portugal and only from America or Australia.
At this point the day had been taken up entirely by investigation work and nothing had actually been altered or replaced. We agreed that finding a way to cut the existing tube in-situ and then fitting the new one over it was the solution. All the fittings were put back as before and I left with a few ideas in mind.
Chapter 2 coming soon ...