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Silica gel is the standard for most purposes. It's the desiccant you find inside those paper sachets packed with new electronic equipment. It consists of tiny beads of silicon dioxide that are nanometres across (so that a little material has a lot of surface area), and although it's called a gel, the material itself is hard at room temperature and pressure....


4

Your last statement is basically correct: Another possible explanation is that the higher air temperature increases the air's water carrying capacity, which in the absence of an abundant water source, extracts water from your body faster. Therefore increasing perceived dryness. Heating air does "dry it out" in a practical sense. For example, a food ...


4

Figure 1. A concrete sleeper mould with reinforcing steel. Concrete sleepers are reinforced with pre-stressed steel. Image source: BFT-International. The sleepers will act as heat sinks during the day soaking up heat from the ground. At night this heat is let off. The steel will conduct heat to the ends of the sleepers warming the end-plates and supplying ...


3

Not to jump the gun from @hazzey, but one of the product description images describes how the cabinet works: The English in the images is a little lacking (probably a translation from a Chinese manual or something), but it seems like the cabinet condenses the moisture inside, then freezes it on a collection board. Once the space is dehumidified, it appears ...


3

Do you know the burning temperature of the wood you intend to use? According to a quick search on the 'net, you're in trouble at about 450° F. Extended temperature at that level will ignite the wood. Your insulation should be inside your enclosure and the enclosure should be non-combustible. A hot air gun blowing into a well insulated enclosure will likely ...


2

Once again, forced to answer because not enough reputation to comment. Several answers/comments have talked about requiring energy to reduce humidity. @Chuck specifically states you need energy to convert from vapor to liquid. In fact, the reverse is true. When vapor condenses to liquid it gives up energy. For water it's approximately 1000 BTU/pound ...


2

To summarize the comments given here: During the winter, the cold air outside can hold only a small amount of water in solution, which means it takes very little moisture in cold air to get it to 100% relative humidity. But then, when your furnace draws in some of that cold outside "makeup" air, it heats it up and its relative humidity then drops ...


2

The formula for relative humidity is the saturation vapor pressure at the dew point divided by the saturation vapor pressure at the ambient temperature. The formula for saturation vapor pressure is: =610.78 * e(t/(t + 238.3 ) * 17.2694)/100 I don't remember where I found this formula, but I use it in an Excel spreadsheet to calculate water loss in my ...


1

you're on the right track (I didn't check your numbers but the method is sound), except: your energy. Expect at least a 3 to 1 gain of a refrigeration system - you can move more energy than what you put in. I learned this as a coefficient of performance. temps are off. You won't be able to cool air to 40 degrees - that would require the coils to be too ...


1

They have collected heat during the day . And being solid they conduct heat better than the loose gravel. So they collect more heat and when cool the heat is conducted back to the surface better than the loose gravel. Under some humidity and temperature conditions the few degrees of temperature causes faster evaporation from the solid concrete. You ...


1

You need to know the vapor pressure of water at different temperature. No simple formula to calculate this exists, however you can hunt down a table - like the one on wikipedia - and then use the Clausius-Clapeyron equation. I've learned to use this form: $$ln\frac{P_1}{P_2}=-\frac{L}{R}(\frac{1}{T_1}-\frac{1}{T_2})$$ With latent heat $L$ and gas cosntand $R$...


1

I don't think you're going to find an answer that meets the intention of your question as I read it. It takes energy to convert water from a vapor to a liquid. Some materials (minerals, sugar, etc.) can absorb water vapor from the air because they are hygroscopic, but it also means that there is a finite limit to the amount of water they can absorb before ...


1

How about this: You blow your humid air through the primary side of an air-air heat exchanger, here it is cooled a bit. Then this air passes through past a cold surface: either outside or underground, depending on oyour local climate. The air cools further and moisture condenses. The cool air passes through the secondary side of our air-air heat exchanger, ...


1

As I commented and @grfrazee answered, the particular dry cabinet claims to freeze the moisture. I think that there is a general consideration that is being overlooked. In the question, you compared the dry cabinet to a room dehumidifier, but a better comparison is probably a refrigerator. A room dehumidifier need to pass a large volume of air through it ...


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