Starting Construction

[Roger]

I did not realize you had pics on this thread already. Wow! Awesome!

[DeeDubya]

Moisture laden air (higher RH) is lighter than dry air. That's right.
Yep, fortunately it has changed my plans for the intake/supply arrangement for the humidifier and I have avoided a major fuck-up. I was planning to pull air into the bypass humidifier from down low and discharge it high hoping for a better RH balance within the humidor. Not so. I need to pull mid to upper level air into the humidifier and blow it downward. Here's why...

Effect of water vapor
The addition of water vapor to air (making the air humid) reduces the density of the air, which may at first appear contrary to logic.

This occurs because the molecular mass of water (18) is less than the molecular mass of air (around 29). For any gas, at a given temperature and pressure, the number of molecules present is constant for a particular volume. So when water molecules (vapor) are introduced to the air, the number of air molecules must reduce by the same number in a given volume, without the pressure or temperature increasing. Hence the mass per unit volume of the gas (its density) decreases.

The density of humid air may be calculated as a mixture of ideal gases. In this case, the partial pressure of water vapor is known as the vapor pressure. Using this method, error in the density calculation is less than 0.2% in the range of −10 °C to 50 °C. The density of humid air is found by:

[1]
Where:

Density of the humid air (kg/m³)
pd = Partial pressure of dry air (Pa)
Rd = Specific gas constant for dry air, 287.05 J/(kg·K)
T = Temperature (K)
pv = Pressure of water vapor (Pa)
Rv = Specific gas constant for water vapor, 461.495 J/(kg·K)
The vapor pressure of water may be calculated from the saturation vapor pressure and relative humidity. It is found by:


Where:

pv = Vapor pressure of water
Relative humidity
psat = Saturation vapor pressure
The saturation vapor pressure of water at any given temperature is the vapor pressure when relative humidity is 100%. A simplification of the regression [1] used to find this, can be formulated as:


IMPORTANT:

This will give a result in mbar (millibar), 1 mbar = 0.001 bar = 0.1 kPa = 100 Pa
pd is found considering partial pressure, resulting in:

Where p simply notes the absolute pressure in the observed system.

Well Slap me Naked.

[craig]

Hmm. Discharge high, absorb low, is what I was taught. This may simply be due to convenience rather than science, though. I guess I could dig out a textbook ...

I'm not disagreeing with the density calculation - but I am guessing (GUESSING) that differences in temperature trump humidity. Temp is not constant, which causes air currents which move the humidity around. Then you realize air is not an ideal gas; it is a mixture, but the equation is meant for ideal gases, and eventually you realize that you need a cigar

A desktop oscillating fan in that room would probably have a big effect on RH distribution.

I'll try to remember to ask a friend of mine (who should know the answer) about this the next time I see him. Unfortunately, we just had lunch yesterday, so I probably won't see him again until July.

The room is looking better and better! I'd consider a smaller cigar cutter, though.

[mrtr33]

This is the part of the project where I just kind of stand in the corner and maybe look at my watch.

[ashauler]

This is the part of the project where I just kind of stand in the corner and maybe look at my watch.

How about you and I just meet in the game room for a smoke Mark?

I'm gonna be adopted soon so it's all good.

[DeeDubya]

How about you and I just meet in the game room for a smoke Mark?

I'm gonna be adopted soon so it's all good.

Sure, just put the ashtray right there in the middle of the poker table. If a cigar rolls off onto the felt, that's OK. The beer fridge is there in the corner. If you don't like what's in there I'll run down to the store while you two pick through my sticks.

I have the adoption papers ready. Are you a pedigree?

[ashauler]

Nope.....mutt all the way, but that pesky neutering thing has been taken care of.

I would never allow the poker table to be desecrated, nor would I disparage your stock of beverages, decimate perhaps, but not disparage.

[Roger]

Seriously! I am concerned that you can see into you humidor from outside the house. I would personally be worried that someone would see inside and get tempted to break in. What about shades or a curtain? I think you are brave to have those windows there. If i were standing outside I would want in!

Not only that but are your windows going to affect you humidity or tax the way you control your humidity? Just a thought.

Awesome project though, I am still thoroughly jealous!

[Irish79]

Seriously! I am concerned that you can see into you humidor from outside the house. I would personally be worried that someone would see inside and get tempted to break in.

The large windows allow viewing and drooling from DeeDubya's game room. The outside entrance does not have a window, but the back side does have a window. However, from DeeDubya's plans, the window is connected to his security system. And so the would be thief has to ask himself, "Do I feel lucky?"

[WOXOF]

Very nice, when is the grand opening herf?

[DeeDubya]

Seriously! I am concerned that you can see into you humidor from outside the house. I would personally be worried that someone would see inside and get tempted to break in. What about shades or a curtain? I think you are brave to have those windows there. If i were standing outside I would want in!

Not only that but are your windows going to affect you humidity or tax the way you control your humidity? Just a thought.

Awesome project though, I am still thoroughly jealous!

Valid thoughts there Roger. There is an outside window, I think it's 2'0x5'0, but will have a blind that closes completely. And of course it's on my alarm system. The inside large windows are really what I'm depending on to help control temperature. They were outside windows before, so they are sealed and double-pane. We've had some 95+ days here lately and the humi temperature has not gone over 75. I spent today installing the humidifier and will post some pics on Monday.

[Roger]

Yup I think that at least a blind will help keep the sun out a bit, as well as protection from any who may be passing through. You never know. Look forward to the pics! Roger