diy solar

diy solar

Electric heater calculations

Again pondering the hot air rises point...

NOTHING in a gravity field rises.

Anything percieved to "rise" is ONLY doing so because something denser is pushing it up.

Cold air falls... period.

Straws dont suck fluid from a drink, a lower pressure area is created, and atmospheric pressure PUSHES the liquid into the straw...

Gravity pulls... it does not push... dense pressurized fluids push...
 
Dude, I wasn't trying to start an argument...

1. 'Air' is everywhere on planet Earth, there is no escaping it.
If you did escape it, you would die.
If you discount air being everywhere we are going to be, then results are going to be skewed.

2. 'Air' is a very low viscosity fluid.
Most components of 'Air' can be compressed into liquid state.
We are just lucky the force of gravity doesn't compress our 'Air' into liquid,
And we are lucky the sun heats the air to keep vapor/gas.

3. ANY heat on planet Earth heats the air,
It's what drives the atmosphere and water cycle.
Any air warmer than ambient rises because it is less dense per volume, warm air pools at the top of closed areas, like room or coolers,
Cooler air than ambient sinks because it's more dense than the ambient temperature.

4. Energy radiated as heat IMMEDIATELY encounters air/moisture/dust particles, things with mass, and warms that mass, the mass absorbing the energy and expanding, becoming less dense in the air column and rises in the ambient air column.

5. The warmer than ambient air rises, that's the movement, which creates both a low pressure cell under the rising heat 'Bubble' or column, and the ambient air pressure forces ambient air into that low pressure cell.
Something has to MOVE FIRST...

6. Closed cell insulation has 'Air' (or other gasses) suspended in it, since that trapped air can't MOVE, the ambient (colder) air can't move in because the warm air didn't move.
Two objects can't occupy the same space at the same time, keep warmer than ambient from migrating up and out, there isn't any room for ambient air to move into place.

7. Energy has to be in the light spectrum to move through a vacuum.
Vacuum coffee mugs prove that, a vacuum space, no 'Air' in the gap between walls, keeps your coffee hot without an 'Insulation' material.
With no air in space, you can easily have a 300° temp change from being in sun, to being shaded by a planet.
The ambient temperature is say, -150°, while solar radiation in the light spectrum will strike the space traveler and raise suit exterior to +150°.

8. Light spectrum energy is just that, light.
When it strikes a surface it changes frequancy from that contact, loosing energy in the process, why a room with a lot of windows heats up in direct daylight.

The surface the light strikes is heated, becoming thermal mass.

9. I use this as 'Passive Solar', 15' of windows at its peak facing south/south east.
In the summer, high sun, I shade the windows with a growing/green vine cover from above.
In the winter the vines die back, low sun gets directly into the home, strikes walls & floor, changes frequancy and sheds heat inside the home when it's needed.

10. Before HVAC, porches and tall windows did the same thing,
Porch shades high sun in summer, low sun got directly into the home.
Instead of heavy drapes to keep heat in, or out, I use triple pane gas charged windows...
Automatically let's low summer sun in, and once it changes frequancy and sheds the biggest part of it's energy, traps that heat inside.

'Low E' coatings on windows reflects high sun, lets low sun in.
I want more sun in winter, so I use green cover instead of 'Low E' coatings.
It's a little more work cleaning up leaves and pulling dead vines back once a year, but it's more efficient when you want passive solar energy.
Nothing COMMON absorbs high summer sun like growing green leaves...

--------

I'm just going by the laws of radiation, motion & thermodynamics.
Insulation slows the migration of energy as heat from equalizing with the ambient atmosphere,
Mostly air tight lids help slow that migration, like on coolers.
There is a reason we stuff more insulation into ceilings than floors, because heat rises in our atmosphere.
If you can keep the heat from rising, ambient cooler air can't come in from below...

It's also why I suggest an inverted box sitting on the bottom insulation board, the inverted box allowing you to easily seal up all cracks/escape routes for warmer air and still allowing easy access to batteries, simply lift the box off instead of trying to reseal a lid everytime you do maintenance on batteries.
 
JeepHammer said:
Dude, I wasn't trying to start an argument...

1. 'Air' is everywhere on planet Earth, there is no escaping it.
If you did escape it, you would die.
If you discount air being everywhere we are going to be, then results are going to be skewed.

2. 'Air' is a very low viscosity fluid.
Most components of 'Air' can be compressed into liquid state.
We are just lucky the force of gravity doesn't compress our 'Air' into liquid,
And we are lucky the sun heats the air to keep vapor/gas.

3. ANY heat on planet Earth heats the air,
It's what drives the atmosphere and water cycle.
Any air warmer than ambient rises because it is less dense per volume, warm air pools at the top of closed areas, like room or coolers,
Cooler air than ambient sinks because it's more dense than the ambient temperature.

4. Energy radiated as heat IMMEDIATELY encounters air/moisture/dust particles, things with mass, and warms that mass, the mass absorbing the energy and expanding, becoming less dense in the air column and rises in the ambient air column.

5. The warmer than ambient air rises, that's the movement, which creates both a low pressure cell under the rising heat 'Bubble' or column, and the ambient air pressure forces ambient air into that low pressure cell.
Something has to MOVE FIRST...

6. Closed cell insulation has 'Air' (or other gasses) suspended in it, since that trapped air can't MOVE, the ambient (colder) air can't move in because the warm air didn't move.
Two objects can't occupy the same space at the same time, keep warmer than ambient from migrating up and out, there isn't any room for ambient air to move into place.

7. Energy has to be in the light spectrum to move through a vacuum.
Vacuum coffee mugs prove that, a vacuum space, no 'Air' in the gap between walls, keeps your coffee hot without an 'Insulation' material.
With no air in space, you can easily have a 300° temp change from being in sun, to being shaded by a planet.
The ambient temperature is say, -150°, while solar radiation in the light spectrum will strike the space traveler and raise suit exterior to +150°.

8. Light spectrum energy is just that, light.
When it strikes a surface it changes frequancy from that contact, loosing energy in the process, why a room with a lot of windows heats up in direct daylight.

The surface the light strikes is heated, becoming thermal mass.

9. I use this as 'Passive Solar', 15' of windows at its peak facing south/south east.
In the summer, high sun, I shade the windows with a growing/green vine cover from above.
In the winter the vines die back, low sun gets directly into the home, strikes walls & floor, changes frequancy and sheds heat inside the home when it's needed.

10. Before HVAC, porches and tall windows did the same thing,
Porch shades high sun in summer, low sun got directly into the home.
Instead of heavy drapes to keep heat in, or out, I use triple pane gas charged windows...
Automatically let's low summer sun in, and once it changes frequancy and sheds the biggest part of it's energy, traps that heat inside.

'Low E' coatings on windows reflects high sun, lets low sun in.
I want more sun in winter, so I use green cover instead of 'Low E' coatings.
It's a little more work cleaning up leaves and pulling dead vines back once a year, but it's more efficient when you want passive solar energy.
Nothing COMMON absorbs high summer sun like growing green leaves...

--------

I'm just going by the laws of radiation, motion & thermodynamics.
Insulation slows the migration of energy as heat from equalizing with the ambient atmosphere,
Mostly air tight lids help slow that migration, like on coolers.
There is a reason we stuff more insulation into ceilings than floors, because heat rises in our atmosphere.
If you can keep the heat from rising, ambient cooler air can't come in from below...

It's also why I suggest an inverted box sitting on the bottom insulation board, the inverted box allowing you to easily seal up all cracks/escape routes for warmer air and still allowing easy access to batteries, simply lift the box off instead of trying to reseal a lid everytime you do maintenance on batteries.
Click to expand...
Goodness, please dont think I'm arguing! I just have a crazy side that points out misconceptions.
I'm happy with corrections, and I take ZERO offence from responses either way.
Peace!

I am trying to educate you and anyone reading this...

Gravity is the force in question. Air is the fluid.
Cooler air pushed the less dense heated air up.
It does not rise simply because it is less dense.
It gets pushed up by the denser cooler air.
 
New Mexico Will said:
Aircraft are much more dense than air, yet they rise. ?
Click to expand...

Bernoulli's Effect.
https://en.m.wikipedia.org/wiki/Bernoulli's_principle

Between Bernoulli's Effect & Venturi Effect I lost my mind learning to flow test throttle bodies, intake manifolds, heads, exhaust systems...
I didn't have a formal education, so constantly playing catch up.
Where I got ahead was electrical fuel injection and ignition systems, let them play catch up for a while!
 
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Supervstech said:
Goodness, please dont think I'm arguing! I just have a crazy side that points out misconceptions.
I'm happy with corrections, and I take ZERO offence from responses either way.
Peace!
Click to expand...
New Mexico Will said:
Aircraft are much more dense than air, yet they rise. ?
Click to expand...
Obviously I was discussing gravity controlled media... an airplane has an engine providing thrust that pushes an airfoil to provide lift... let's not get too many arguments going here.;)
 
Supervstech said:
Obviously I was discussing gravity controlled media... an airplane has an engine providing thrust that pushes an airfoil to provide lift... let's not get too many arguments going here.;)
Click to expand...

I was just screwing with you (intentional jet engine pun)
 
Standing up at the chalkboard after writing out s single calculation measuring seventeen feet in total length, then saying with a GerManic scientist's accent, "it is zee reduction of air pressure over zee wingin that creates zee liftun uppen".
 
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OK!

I'm of the physics side of things, what moves first is the 'Cause', anything after that is 'Effect'.
Nothing interesting happens until something moves, the faster it moves the more interesting it gets.

I'm used to guys that think bullets "Speed Up" AFTER they leave the muzzle,
When you pull a powered lawn mower backward, the blade turns backwards,
That fossil fuel is "More Efficient" (despite 80% thermal losses) than electrical energy,
That DC pushes through long runs of wire just as good as AC does,
That air (atmosphere) 'Sticks' to the earth, not gravity pulling on the air column,

If you want to argue that less dense, warmer air is 'Pushed Up' or rises on it's own doesn't matter,
What matters is ambient, cooler air replaces it, and I don't think anyone argues that effect, the end result.
 
Heat being at a higher energy state of molecular activity than cold, is drawn towards cold ... did I do good?
 
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I was trying to explain the diameter of a wind generator rotor (blades) was limited by the tip speed,
The tip speed being increased the longer the blade is,
I got that glazed over look and called 'Stupid'...

Resistance expands exponentially as tips approach the speed of sound so the tips can't exceed the speed of sound without reducing force the wind applies to the blades, so rotor diameter is limited...

I'm sure you all get the same thing when you try to explain Watts/Volts/Amps conversions and what's more efficient for an application...

Trying to explain you can move a vehicle with a 12 volt battery, starter motor & gear reduction doesn't mean it's the most efficient way to do things!
Or trying to explain why 110 volts uses a smaller conductor (wire) does the same work as a big, fat 12 volt battery cable...

It's REALLY NICE to be someplace that the laws of electricity, thermodynamics, motion actually apply!

To me, it's density, less dense rises.
Substitute a closed tank for trapped air,
Substitute air for water.
Fill a tank with water in the ocean and it's sinks.
Displace water with less dense air, or even diesel fuel (another liquid) and the tank rises.
Air and diesel being less dense than water...

Water around the tank is displaced as it rises and fills the void the tank left below it,
The less dense tank being what's moving.

The results are the same, less dense moves up, no matter if it's rising on it's own or being pushed.

I'm just glad to have people that can visualize the concept and don't say "Fake Science"!
 
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JeepHammer said:
You did great... Now have a cookie and take a nap in your Trump blanket... ;)
Click to expand...
Now keep your ushanka on, I do understand that It is difficult to envision the advantages of minimal enslavement to omnipotent government by those who have been raised by it. ?
 
offgriddle said:
Now keep your ushanka on, I do understand that It is difficult to envision the advantages of minimal enslavement to omnipotent government by those who have been raised by it. ?
Click to expand...

I had to look up ushanka, here they are 'Dog Ear' caps! ;)

Not getting political, it was a poke at the science deniers.

I pay my taxes, I vote, I don't use toxic chemicals so the EPA doesn't want to cook me, and I don't take or grow illegal drugs,

The fact I 'Opted Out' of the 'Mainstream' way of doing things doesn't have a political motivation, it's a personal choice...
Off Grid solar power, water wells, home gardens, earth sheltered home, pretty much nothing 'Mainstream',
Clean food, clean water, sustainable power... All personal choices.

I OWN my power & water.
My food & water is clean, and the food is exactly what I want, I don't have to 'Settle' for what's on the shelf at a store.
The home is earth temp stabilize and super insulated,
Poured concrete lasts at least 75 years with no maintenance at all, and if you have a look at Roman construction, may last 2,000+ years.
It's fire proof, bug proof, tornado proof, and even if it floods (well above historic flood plane) it has floor drains and concrete doesn't suck up water.

With radiant floor heat and super insulated, it's the most energy efficient COMMON way *I* could find to do things.

Won't suit everyone, but it works for us,
Getting older, so flat floor plan and wide doors.
Not many people in their 30s think about the other end of life in a wheel chair,
And NOT paying a crap ton of insurance, utility bills, upkeep/repairs leave a lot of money for expansions in solar, etc.

It's all in how you commit, I was in, 100% committed (and probably should have been committed a few times ;) ),
I intended to die here, and still do...
Until I'm dead, I intend to have a good time! :)



Politics be damned, economy be dammed, trends & fads be damned, this is my 'Alamo'...
 
QUOTE="New Mexico Will, post: 17182, member: 783"]
Please lets not get into politics.
[/QUOTE]
I'll second that vote, I mean ... you know what I mean!
 
New Mexico Will said:
I need a way to get some heat into my little 64 square foot shed where my batteries live. I'll do something permanent over the summer, but for now I just need something that works. I tried a Mr. Buddy propane heater, and my building is airtight, so the oxygen sensor shuts it off after a few minutes. I picked up this little heater to try. Am I figuring this right?:

250 watts / 110 volts = 2.73 amps

2.73 amps * 8ish hours of run time = 21.84 amp hours.

I have 2x200ah batteries in parallel, so 400ah- 200ah (safe dod) - 21.84=178.16 amp hours remaining.

Did I figure that correctly?View attachment 2539
Click to expand...

The First step is to calculate how much heat you need in btus at maximum weather conditions. This will involve determining the insulation values of your structure and other info and plug data into a manual J calculator or similar heat load calculator. You will then know you will need X btus of heat. For an easy example let's say you need 2000btus to handle the load while you are at peak weather conditions. Electric heat strip heat to power conversion is approximately 3.41 btus per watt of electricity. Some rough math 2000 btus = 587 watts. I doubt you will find a 587 watt heater so find the closest size that is HIGHER. Like a 750 watt heater. You will need to make sure your equipment can run the 750 watt heater, but at peak load the heater will still cycle off when it meets the thermostat setpoint. Meaning in an hour it will use a maximum of 587 watts. I'll check back in later and make sure I didn't put any errors, answer any questions.
 
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