.

What size are the solar panels.? And the battery that will have to see the heating through the dark of night.?

Not an expert by a long way on this, but I cannot see this stacking up.

Nick

Hi Martin,

Welcome to the forum, apologies in advance if this comes across as a bit negative, but I wouldn't like you to invest several hundred quid and discover that it doesn't work.

I'm afraid that you will need a lot of solar panels. In simple terms think about how much the sun heats the roof of the shed on a winter's day – not enough to make it feel warm to the touch. A roof-sized solar panel can't get more energy than that, so you would need to cover amuch larger area with panels.

300W may not seem a lot, but on 24/7 is 7.2 kW hours a day, which is 600 amp-hours at 12V – that means you need enough solar capacity to charge ten car batteries during the eight hours of weak daylight on an overcast winter's day. One website estimates that a 100 watt-hour panel will only generate one 100 watt hours on a dull winter day – only enough to run your heater for twenty minutes.

You could be better off getting a solar water heating system for the house, and using the fuel savings to insulate and heat the shed.

Neil

Hi Martin,
First I do not believe the figure given by the IR panel supplier of maintaining a temperature of 60/65 Deg F If they had done their calculations the would only be able to say it would raise the temperature so many degrees above the outside temperature. My shed is a brick outer skin then a 2" gap then thermalite blocks. 300 watts would not hold the temperature any where near 60/65 Deg F with an outside temperature of say 5 Deg C (41 F)
Like Hamish I do not understand "3-21/2 watts" This is how I would do the calculation. In winter it goes dark at about 16:00 and gets light at about 08:00 So you have 8 hours to charge the battery and the battery needs to provide 300 watts for 16 hours. This is 4800 watt hours (Assuming a 12 volt battery 400 AH capacity) To replenish this in the 8 hours of daylight you would need 600 watts from the solar panels plus the 300 watts to power the IR panel during the day so you need a 900 watt solar panel. I do not know the cost of the solar panels but a 40 AH car battery is about £40.00 so you would need about £400.00 worth of batteries. Even if you use the heater with a 50% duty cycle (ie half the above calculation.) it is still a high capital investment. I think using a dehumidifier as already suggested would be better as you would gain the latent heat of evaporation of the water condensed.

Les.

You might like to talk to boaty people on this one since this is always a problem on a wooden boat. Take a walk around any marina at any time of year and you will see they will have the front hatch open all be it just a bit and one open at the far end of the boat.

It is hoped that this will induce a stream of air through the boat sufficient to keep her reasonably dry and at an ambient temperature with the outside. Not forgetting that they have to have water in the bilge to keep the planks swelled and the boat water tight. IE no hope of drying out completely.

If you continually wet and dry wood it will rot very quickly. Note the boats on hard standing having water line planks renewed.

I think I would settle for an electric fan heater when feeling cold aimed at ones self and a store of WD to disperse the damp from machinery and spray at the end of play.

Leave a window or two open just a tad…. I'll bet you you're thinking what about the burglars!!! Truth is if they want to get in they will find away. I also think Harvey Kietle is wrong saying fit a burglar alarm since it takes the cops about two days to respond around here. This is just my opinion of course.

Jesse

Hi All I have one small oil filled rad with thermostat turned to hold temp. at about 10 degrees,plus one small dehumidifier (drains off about 100 mil per week) depending on weather ,That's maximum amount. Humidity is between 60 to 70 on my meter. No rust in 5 years ,Cabin 3×4 meters with 1 1/2" walls insulated with CELON sheets ,roof with 4" fiber glass, Happy with that ,it's working for Me.

Maurice

This is the best renewables forum in the uk. although it is run by a company they are very hands off like here.

Battery – no chance. You can barely keep the lights on with solar. A lead acid battery, even a deep discharge one (which is a total con anyway) must not be discharged more than 50% if you want it to last more than a month. The deep discharge bit just means you can get away with it a handfull or times rather than just once with a regular battery.
You need to make it totally airtight, then run a dehumidifier that has a compressor off the mains. The ones <£100 that use a peltier are rubbish. The ones that use some kind of dessicant are also rubbish.
While you are doing the 1 in of insulation you might as well do 2 in.
if you have uncontrolled ventillation it just lets more damp air in when the orignal air has condensed all its water. It needs to be controlled and only opened when you are in there or it is very dry outside.

Solar panels are no good for applications which require direct energy supply in the winter as they are a seasonal source of energy. Nothing to do with Bob's claim of only 20% of rated output – a 250W panel on a narrowboat will run TV, lights and keep the starter battery topped up all summer.

We only get 1/6 as much energy from the sun in winter due to seasonal variation, so as a first estimate you need six times as many panels in winter.

A 300W IR panel fed by a 70% efficient inverter will use 428 watts from the battery.

Even assuming battery charging is 100% efficient, to run the panel for 12 hours a day will use 428*12=5142 watts.

Now as its dark winter days that means you need about 5 kW of solar panels, typically what you would have to power a house.

The difference is the house panels feed the excess into the grid in summer and you take extra out of the grid in winter and at night.

Neil

Hi Bazyle,

I saw the 1 star treatment too

I don't know why those reviewers had that experience. I can only qualify the experience I have had as follows:

1. When I first started attending the shows – about 10+ years ago, I didn't know anything about protecting the machines overnight and in transit/storage pre and post shows. I watched the competitors spray their machines with WD40 at the end of shows for the onward journeys back home. So, I did the same. Nice and cheap. On one occasion, I left the machines overnight in the Luton, as it was cold and wet outside, and I didnt fancy offloading at night in this weather. In the morning took the machines out to put back into our display. Removed the transit shrinkwrap, and still saw some rust film on exposed surfaces. Some expletives later, cleaned and oiled the machines. My team and I have many such experiences with WD40. Finally, Paul Price from Shield came along and introduced us to Metalguard Ultra, which initially we regarded to be an expensive gimmick. We proceeded to try it and found it worked. This was also used as part of our preparation service when we used to offer it. As soon as machines were prepared, we sprayed them with the metalguard to avoid transit rust, be it to destinations in U.K. or Europe, because we had no idea of transit/storage conditions. We even suggested it to SIEG, but they considered it to be too expensive for transit protection. they preferred the white grease or red grease (lovingly referred to as chicken fat)

2. Originally before we discovered metalguard, we had to regularly clean our display machines and wipe the tables with oil soaked rags at least once a week, depending on how many visitors had been and touched them. Once we started using metalguard, we clean our machines once every two odd months or if needed, followed by a fine mist treatment with metalguard. Before, rusty figures were quick to form marks on exposed surfaces. I admit that the temperature is above 17 deg.C, but still, rusty figures are rusty fingers. For colder temperatures the user might have to clean/apply metalguard more often maybe, depending on various factors, but in my opinion, this stuff protects far better than WD40, for sure. As the spec. on Shields site says: it complies with defence and NATO standards. We have been using it now for well over seven years, and we are happy with it.

This product had also been well tested by one of the largest specialist woodworking tools companies in Germany over an extensive period before they got the confidence and comfort to buy it from Shield and sell it. Their purchase volumes from Shield are very high.. Similarly, their sales into USA have also grown over time.

Initially, we were the only main U.K. seller for their product. Then Axminster came on the seen, purchased from them and our sales for this product reduced by 50%. A year later, machine-dro started stocking SHIELDs product to complement their Ultrasonic tanks related product range, resulting in a further drop in our sales. We are in business to make money, just as SHIELD and others are. If the quantity of sales become nonviable, as they did at the time, it is difficult for us to invest in advertising and promoting their product in the way we did at the time, pre the competitors. We had certain verbal agreements at the time which failed, resulting in the commercial decision to drop the product at the time. Our and SHIELDs position today is different to how it was for both of us at the time we dropped their products.

Whatever the commercial reasons, I am still comfortable that their products work. Their products are much more popular now, and I feel that too speaks volumes and should be taken into consideration, if we are to make any judgement on quality….and they hardly do any advertising or marketing of their own. SHIELD is a small British business which has come a long way.

They also do a wax polish which works.

At the end of the day, we all have our own experiences.

Ketan at ARC

My workshop consists of a precast concrete garage, standard 16'x8'. It was refurbished a couple of years ago, when the original corrugated asbestos/cement roofing was replaced with Kingspan insulated panels. Apart from that, no other insulation has been installed, the walls just being covered with white masonry paint. The floor is unpainted concrete (painted floors generate condensation), laid on a dampfroof membrane, on hardcore, ABOVE surrounding ground levels . ALL eves gaps have been closed and draught strips fitted to the double wooden access doors that are at one end. My machinery is very lightly oiled, as a precaution, but handy files are not (naturally), nor are hammers and pliers, etc. In Winter, I do not 'heat the workshop', but run a cheap dehumidifier (24/7) that has a powerful air flow out of a vertical outlet that circulates dried air throughout the 'shop. A small (set at 600W) fan heater is positioned to blow across the front of the dehumidifier (inlet grill), it's thermostat set so as to maintain the min'm inlet temperature required by the dehumidifier, around 4 degs C locally, to avoid the possibility of icing-up the heat exchanger coils. The phylosophy behind this is to AVOID heating the air in the workshop to the point where it can support higher moisture retention. Any bare wood in the 'shop (there is a small stock) has been dried out to the ambient levels sustained, as has the bare concrete floor (I do use domestic doormats to stand on in strategic positions). I couldn't say that the building is completely airtight and that I gasp for air when in there, but the dehumidifier is powerful enough to deal with any leaks and, of course, my exhaled moisture! I do open the shop doors and window when generating fumes of any sort, but I do try and arrange such activities around drier outside atmospheric conditions. If I am planning to work in the 'shop during very cold weather I usually nip in there early and 'jack up' the thermo' on the fan heater, it has a higher output of 1.6kW, to lift the temperature modestly (I don't need to work in simulated summer-like conditions, or attire!). Lifting the temperature of dry air is not going to create undue condensation on cold metal, and the warmer air only makes the dehumidifier more effective anyway. However, care is taken when starting cold motors…!

Summarising, then, I don't have rusting in my 'shop! The dehumidifier collects about 4 litres of water every 3 to 4 days, which is both startling but gratifying and which dispels any thoughts that dessicant alternatives might be cheaper!! I consider that the cost of running this system is well justified, given the value of the contents of and the 'shop as a whole!

Trev T