As it has been a while since the last posting i thought i had better post some comments about the winter performance of my solarventi unit. Despite some longish periods of gloomy and wet weather there has been ennough occasional sunshine to maintain a dry fresh smelling atmosphere in my farmhouse. The sun is obviously much lower in the sky now and there are a couple of trees that block the sun for part of its trajectory. The distant trees that i thought might be a problem are not! They have shed all of their leaves and the sun shines through the trees albeit at slightly lower power response from the solarventi fan unit. Nevertheless the very effective drying ability of the Solarventi is powerfully in evidence in the whole of the downstairs of the house not just the utility kitchen area.

I understand the larger Solarventi units provide substantial heating inputs into a property. I am going to investigate that as my heating bills have gone up way beyond inflation due to the rip off utility companies. Anyway i like the idea of free energy and being a green virtuous person. There is also a new solarventi device I am investigating that does both water and warm air - see http://www.solarventi.co.uk for details

Having a Solarventi has made the house much easier to heat now the cost increase is in spite of using less energy. I have also discovered that a house with a dry atmospehere is much quicker and easier to heat than one with a 'wet' atmosphere, basic physics I know, but experience of using a Solarventi drives home the lesson!

Well since the last instalment there have been two events worthy of note - the first was the freak thundery squall we had a few weeks back which blew down the wooden frame that my SolarVenti is mounted on. The frame was a bit flimsy on reflection. The SolarVenti was wrenched off it and some rain had got inside it! I drained it and tested it and it was still working and left it propped up in the sun and it quickly dried out. I can see now why it is best mounted directly on a wall!! Anyway it is now remounted on a strengthened wooden frame and working really well.
The next event was one of those incredibly hot days we had - that was the only time that I have needed to switch it off. That was the day that i was prompted to mount the On/Off switch. That was supposed to be a five minute job but it is not that simple. It is not like any switch I have encountered before and I could not find a diagram. Anyway i took it apart and tried to work out how it worked and performed a test assembly off the wall. In short I lost patience and the chap at SolarVenti had to explain it to me over the phone. Anyway it works although I still leave the SolarVenti unit it on all the time.

Is the dehumidification process still working - yes - it is now probably the driest room in the downstairs area of the house. There was one July day when it was incredibly humid and if you twitched you broke out in a sweat - that was the only day the cheese stone has shown any slight colour change from the grey/white completely dry colour.

I have been thinking about my cellar which unfortunately is on a North and West facing aspect. It is very damp down there and has a hippo pump in a sump on all the time. It is often below groundwater level and the walls are always incredibly damp at the base. Unfortunately the walls are 3 feet thick and just drilling the hole is a major problem. Would the scale of the damp problem be a bridge too far? I really would like to see if a SolarVenti could make the cellar more usable. My other solutions such as under floor land drains into the sump and the pot bellied stove hardly touch it and anyway i already have a dehumidifier down there full time in the autumn and winter and most of spring. The problem with a dehumidifier, apart from the running cost is that it packs in when it is below 5 degrees C failing just when you need it most!

I suspect that A SolarVenti would remove most of the symptoms such as the foul damp air but obviously it is not going to remove the source of the damp. Just how do you drill a 3 foot hole in a listed building??

I first started this blog a few weeks back but left the first post as a draft for far too long, which is why the first two posts are very close datewise

Anyway a friend asked me how i knew that the SolarVenti was being effective. I was tempted to ridicule this question but bit my tongue and thought about it. Apart from no longer having that feeling of a cooler atmosphere that one gets in a damp room/house and no longer smelling traces of mustines and staleness that one senses in the air, what proof did I have? I do not have any scientific instruments.

However, I do possess the cheese stone that remains installed in the corner of the old dairy room that the SolarVenti pumps air into. It used to have a cheese press on top of it - now it is just a grey stone. However this stone is like a piece of seaweed - it is incredible sensitive to humidity and changes colour accordingly. At one time i thought it was a greenish grey stone. It was not until it dried out that I knew the true colour was greyish white when dry! Not very scientific I know but it great visual evidence.

Back to the title, the atmosphere really has changed in the old dairy (now utility) room and the adjoining room (the kitchen). It is now genuinely pleasant to stand in there and take in the air! I reckon those SolarVenti boys are missing a trick here they should be marketing clean, sterilised (by the sun) warm dry air ventilation all year round as well as pushing the dehumidifier angle. The girlfriend says it is a great drying room too!

I must fit the 'off' switch that is supplied if we have any more days like wednesday - record breaking temperature day!

I thought it would be interesting to see if the manufacturers claims were valid so i started measuring the temperature of the incoming air into the Solarventi and the temperature as it emerged into the room.

Although the dehumidification effect is extremely effective, I found that the incoming air temperature was only being raised by between 8 and 11 degrees C versus the promised 15 degrees and promptly called the supplier. They asked a few questions and then provided the following explanation. Attempted summary:

If the fan is unregulated and the solar cell is brand new then it will whir away at a fair old rate due to higher voltage 13+ V being generated - which it does - regardless of the temperature you want. When the solar cell settles in, the voltage that it generates drops a little back to 12 volts. However that still did not explain to me why i was not getting the claimed maximum 15 degree uplift.

Again the explanation was that if the airflow in the device can be slowed down then the full uplift is achievable under ideal sunny conditions. The two alternatives that emerged were that i wait for the solar cell to settle in which is what i am doing. When it is settled in it will generate less power and the unit will perform to spec. The alternative is to buy a regulator which is apparently supplied as standard on the larger Solarventi units. It is not an expensive item about £25 but could be important for full control of the device in some circumstances. Anyway I thought i would wait and see before getting one. With the current heatwave the air is quite warm enough and the unit is performing well - my girlfriend is going to put the washing in that room to dry now. I still haven't wired up the off switch that was provided for the device.

I just learned that the SolarVenti unit I purchased was the first one installed in the uk and I thought it would be useful to build a diary of its issues and things i learn for others to share.

Why did i buy a SolarVenti? I have residual damp atmosphere issues in certain rooms in my house which is a Period building. (Note not a holiday home - this is in my house). What about a conventional dehumidifier? Well i have tried one of these but it was a pain in the backside emptying the 'bucket' when you find it has switched off and i once tripped over the flex and hurt myself. Anyway it then packed in and it was cheaper to buy another one than to get it fixed! The idea of using the sun's energy appeals to me but more importantly there are no cables and hoses and buckets and nothing to fail on a SolarVenti. The lack of an electricity bill is a big bonus that i can bank for the future years. My SolarVenti is installed on my grade 2 listed building dating back to the 1500's. The house does have a 'DPC' basically a piece of wire cut into the wall and connected to the electricity supply. This runs all the way around the building in a loop. That is the basis of a so called electro-osmotic DPC - but they just dont work properly. Hence the need for the SolarVenti.

Now the big question does the SolarVenti work? Well yes it undoubtedly does but it would be a bit simplistic to leave it at that.

The SolarVenti is installed on a wall of the former dairy room where in the days the house was part of a working farm and they made cheese in the room. This would have been a wet room as the floor is 12 inches lower than the rest of the house and the previous floor which i replaced was quarry tiles laid over sand. The walls of my house are 33 inches thick so it is a non trivial exercise to put a hole through the wall. This lead to some innovative thinking by the people at SolarVenti as I did not want to get in (even more) trouble with the planning people over altering a listed building. Anyway Dave at Solarventi kindly built a wooden frame and mounted the unit on that ducting the airflow in through one of the small window panes which was replaced by a drilled wooden panel. It soes not look as good as a conventional install would but nobody can see it so who cares.

Anyway the SolarVenti ( an SV7) works well and since installing it there has been a really fresh and pleasant atmosphere in that and the neighbouring rooms and I have left it running through the summer period. If there really is a heatwave i might have to wire up the switch that was provided to power it off but that has not been a problem so far.