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.