Vapor Barrier and Air gap Ideas

[highdesertranger]

it takes a huge amount of energy to change the temperature of water. not sure what you mean by moving heat. highdesertranger

 

[Trebor English]

Moving heat like from a cylinder head to a radiator.

 

[DannyB1954]

it takes a huge amount of energy to change the temperature of water.  not sure what you mean by moving heat.  highdesertranger

Why do you suppose they use water in a vehicle radiator? Many buildings use water for heating and cooling. They could just pump air through the system. It takes 1 BTU to heat one pound of water one degree fahrenheit. That in fact is the definition of what a BTU is.  Is that huge? Heat transfers both into and out of water very easy. Water has the capacity to carry large amounts of heat, maybe that is what confuses you. 
If you sit in a bathtub and the water gets cold, turn on the hot water. You can feel how quickly heat flows through the water without it being agitated. Just because something does not conduct electricity doesn't mean it will not transfer heat, or vice versa. Vehicle radiators are now made of plastic. If plastic did not transfer heat well, they wouldn't use it. 

Some things do not transfer electricity or heat well. That does not mean that all things that do not transfer electricity will not transfer heat. 
Stainless steel does not transfer heat as well as copper does, but it does conduct electricity. You can weld or braze on one end of a fairly short piece and pick it up with a bare hand at the other end.

 

[Trebor English]

DannyB, when it is cold outside the steel skin of a vehicle is wet on the inside due to condensation.  Insulation only makes the steel temperature closer to the outside air temperature, colder.  Ideally there should be one vapor barrier and it should be on the warm side.  That's inside in the winter and outside in the summer with AC.  Having pink fiberglass batting on the outside of a van would reduce the condensation from the Mr. Heater Little Buddy by keeping the steel warm.  It would look funny and blow off at highway speeds.  A plastic sheet between the drywall and the insulation works in houses.

 

[DannyB1954]

If water does get behind the inside vapor barrier, how does it dry out? Maybe the problem is the non vented propane heater. You are creating a sauna, then trying to fix the result with something that can create another problem. One of the heaters I own is propane. I am thinking about building a simple air heat exchanger so that I can bring in fresh dry air and not lose a lot of heat . I am also checking into other forms of heat. Wood, kerosene, Coleman fuel. I think the heat exchanger would be the best solution as breathing combustion gasses of any type probably is not so healthy for us.

 

[29chico]

Why do you suppose they use water in a vehicle radiator? Many buildings use water for heating and cooling. They could just pump air through the system. It takes 1 BTU to heat one pound of water one degree fahrenheit. That in fact is the definition of what a BTU is.  Is that huge? Heat transfers both into and out of water very easy. Water has the capacity to carry large amounts of heat, maybe that is what confuses you. 
If you sit in a bathtub and the water gets cold, turn on the hot water. You can feel how quickly heat flows through the water without it being agitated. Just because something does not conduct electricity doesn't mean it will not transfer heat, or vice versa. Vehicle radiators are now made of plastic. If plastic did not transfer heat well, they wouldn't use it. 

Some things do not transfer electricity or heat well. That does not mean that all things that do not transfer electricity will not transfer heat. 
Stainless steel does not transfer heat as well as copper does, but it does conduct electricity. You can weld or braze on one end of a fairly short piece and pick it up with a bare hand at the other end.

You got a lot of stuff right in the above.  However, radiator end tanks are commonly made of plastic these days.  The rad core, that actually does the liquid to air heat exchange, is made of metal. Often the rad core is made of aluminum on modern vehicles.

The plastic rad end tank that receives the hot coolant from the engine will often crack and fail in the 150-180k miles range because of the extreme heat cycling it is exposed to.

 

[DannyB1954]

I stand corrected on radiators. I was trying to find illustrations showing that electrical conductivity and heat transfer resistance are separate properties. An item can be good for one, and not good at all for the other.

 

[highdesertranger]

and you don't think an engine produces a huge amount of waste energy in the form of heat. like I said it takes a huge amount of energy to change the temp of water. a car engine is better at making heat then it is making the car go. how many BTU's are in a gallon of gas? how efficient is a modern gas engine? where do all those extra BTU's go? large bodies of water have a tempering effect on the temperature of the surrounding area. that's why its cooler on the coast in the summer, it is also why it's warmer along the coast in the winter. highdesertranger

 

[Cammalu]

http://www.outsideonline.com/2101176/wayfarer-vans-brings-affordable-mini-camper-america


I don't know how effective this barrier is for the walls and window but I love how fast it all goes together.

I love to sew and think it would be fun to make these. I can't as I'd have to have the exact layouts of different story vans, etc. but someone might take some of these ideas and run with them



Sent from my iPhone using Tapatalk

 

[DannyB1954]

and you don't think an engine produces a huge amount of waste energy in the form of heat.  like I said it takes a huge amount of energy to change the temp of water.  a car engine is better at making heat then it is making the car go.  how many BTU's are in a gallon of gas?  how efficient is a modern gas engine?  where do all those extra BTU's go?  large bodies of water have a tempering effect on the temperature of the surrounding area.  that's why its cooler on the coast in the summer,  it is also why it's warmer along the coast in the winter.  highdesertranger

Pure water, (no minerals or salts), does not conduct electricity, but it does conduct heat.  If water did not absorb heat easily and lose it easily, it would not be pumped through heating and cooling systems. Your theory that if something does not conduct electricity, it will not conduct heat energy is flat out wrong. Electrical conductivity and heat transfer ability are two separate and different properties that each substance can have.

Engines do create heat which is transferred to the water, and then transferred to the air. Try cooling an engine with a heat insulator.  Water continuously circulates in an engine. If there is 2 gallons of water that is about 16 lbs. This 16 lbs is transferring heat continuously so each time it passes through the engine or radiator it can pick up or lose heat. Over a period of time doing so it does move a lot of heat. If the temp in the radiator drops 100 degrees, each pound of water has transferred 100 BTU of heat energy in the amount of time it takes to make the round trip.  I don't know what the time is, but for illustration say it takes 30 seconds for the water to make a complete cycle. So 100 BTU per pound every 30 seconds is 200 BTU per pound per minute, (100 x 2),  or 12,000 BTU per pound per hour, (200BTU per min x 60min per hour). 16 lbs of water can transfer 192,000 BTU per hour, (12,000 x 16). 

At sea level,  between 33 and 211 degrees it takes only one BTU to change the temperature of one pound of water one degree fahrenheit. This is not debatable. This is not a massive amount of energy. A small air conditioner moves 5,000 BTU per hour, a Mr. buddy heater up to about 18,000 BTU per hour. If you have 16 lbs of water and change the temperature one degree that is 16 BTU. If you change the temperature 100 degrees that is 16 x 100 or 1,600BTU. How much heat can be moved depends on how much time it takes to make the cycle happen. IT DOES 

Changing states between ice and water, or water and steam is a different story.  Ice to water is 144 BTU per pound, water to steam is 970 BTU per pound of water.

 

[DannyB1954]

and you don't think an engine produces a huge amount of waste energy in the form of heat.  like I said it takes a huge amount of energy to change the temp of water.  a car engine is better at making heat then it is making the car go.  how many BTU's are in a gallon of gas?  how efficient is a modern gas engine?  where do all those extra BTU's go?  large bodies of water have a tempering effect on the temperature of the surrounding area.  that's why its cooler on the coast in the summer,  it is also why it's warmer along the coast in the winter.  highdesertranger

Pure water, (no minerals or salts), does not conduct electricity, but it does conduct heat.  If water did not absorb heat easily and lose it easily, it would not be pumped through heating and cooling systems. Your theory that if something does not conduct electricity, it will not conduct heat energy is flat out wrong. Electrical conductivity and heat transfer ability are two separate and different properties that each substance can have different amounts of each.

Engines do create heat which is transferred to the water, and then transferred to the air. Try cooling an engine with a heat insulator.  Water continuously circulates in an engine. If there is 2 gallons of water that is about 16 lbs. This 16 lbs is transferring heat continuously so each time it passes through the engine or radiator it can pick up or lose heat. Over a period of time doing so, it does move a lot of heat. If the temp in the radiator drops 100 degrees, each pound of water has transferred 100 BTU of heat energy in the amount of time it takes to make the round trip. 16 lb of water dropping 100 degrees transfers 1,600 BTU.

 I don't know what the time is, but for illustration say it takes 30 seconds for the water to make a complete cycle. So 100 BTU per pound every 30 seconds is 200 BTU per pound per minute, (100 x 2),  or 12,000 BTU per pound per hour, (200BTU per min x 60min per hour). 16 lbs of water can transfer 192,000 BTU per hour, (12,000 x 16). 

At sea level,  between 33 and 211 degrees it takes only one BTU to change the temperature of one pound of water one degree fahrenheit. This is not debatable, (Google BTU). This is not a massive amount of energy. A small air conditioner moves 5,000 BTU per hour, a Mr. buddy heater up to about 18,000 BTU per hour. If you have 16 lbs of water and change the temperature one degree that is 16 BTU. If you change the temperature 100 degrees that is 16 x 100 or 1,600BTU. How much heat can be moved depends on how much water you have and how long it takes to complete a cycle, (also the difference between the water temp and the surrounding temp. The greater the difference, the faster heat will flow).   It does not take a massive amount of energy to heat water. You can move a lot of heat with water, but that is because it accepts and loses heat easily, (a very poor insulator). It is all done at a rate of 1 BTU per pound. 

Changing states between ice and water, or water and steam is a different story.  Ice to water is 144 BTU per pound, water to steam is 970 BTU per pound of water, (when you boil water that is what you are doing. Making water into steam). If you could control your cooking to 211 degrees max, you would save a lot of energy and get about the same result as cooking at boiling 212.

 

[DannyB1954]

My last sentence is probably confusing and it is too late to edit, so to explain. Let's say we are at Sea level, (things change with altitude, water boils at a lower temp on top of a mountain). As water changes states between ice and water it absorbs 144 BTU of energy for every pound. From there to boiling it takes only 1 BTU to change the temperature one degree, or 180 BTU to get it just under boiling, (212 minus 32). To change it to steam takes 970 BTU

One gallon of water weighs roughly 8 lbs. so per gallon we would have to multiply the above numbers by 8. The above numbers would work for a pint, (1/8 of a gallon). Let's say you have a frozen pint of water and want to boil it all off to steam your clothes. It would take 144 BTU to change it to water, 180 BTU to get it just under boiling, and 970 btu to change it to steam. a total of 1,294 BTU. to change the temperature of water takes a lot less energy than to get it to change physical states.

No matter how much energy you put into the water at sea level it will not go above 212 degrees. The water will boil off quicker, but the temp will not go above 212, (unless you are using a pressure cooker). Since it is the temperature that cooks and not the bubbles, cooking at 211 degrees saves you 970 BTU. Once your water starts to boil, you lose nothing by turning down the heat so that it just barely boils. You save fuel.

 

[highdesertranger]

a radiator in a vehicle does not drop the temp 100 degrees. it's not even close, you would be lucky to get 40 a degree difference between inlet and outlet temp. you keep saying pure water. pure water does not exist in nature the closest you could get is rain water but it too has impurities. according to wiki distilled water is ALMOST an insulator(look it up) almost being the key word. if you think pure water doesn't conduct electricity fill a bathtub with distilled water get in and drop a plugged in radio in. or pour distilled water over your keyboard. I was taught that pure water DOES conduct electricity but not that well, regular water conducts it better and ocean water being the best conductor. so I think we can agree to disagree on the conductivity of water. highdesertranger

 

[DannyB1954]

I am done. have it your way. Water is a heat insulator and glass conducts electricity.

 

[surfmore72]

Lol... So the bubble wrap is a decent enough of air gap then. Thanks

 

[highdesertranger]

yes, the bubble wrap works. highdesertranger

 

[Gary68]

"Carmen Johnson, 15, was a high school cheerleader who enjoyed life, got good grades and loved to be on the water.

It was a terrible accident on the water that took Carmen’s life on April 16, and her parents, Jimmy and Casey, are warning others about the potential dangers.

The Johnsons say Carmen, their youngest child, was electrocuted while swimming in the lake behind their home. Her parents told ABC News that the electrical currents came from rusty electrical work at the dock in their backyard.

It’s called electric shock drowning -- when a current, usually from a short circuit in the wiring of a dock, marina or boat, spreads through the water, and someone in the water is shocked and drowns."
http://abcnews.go.com/US/grieving-p...electricity-daughter-killed/story?id=39472764


please,please do not use water in you engine cooling system,it doesnt work good and will rust and corrode the rad and engine

and while layers/barriers like a house window will provide good insulation ventilation is very important in preventing rust,rot ,molds and mildews

 

[BobBski]

My plan is to glue reflectix to bead board and then attach the bead board to cross supports in my ceiling. This will provide an airspace between reflectix and most of the outer vehicle wall and ceiling. May even put 2 layers of reflectix. How effective will it be??? I'll let you know in about a year.

 

[surfmore72]

My plan is to glue reflectix to bead board and then attach the bead board to cross supports in my ceiling. This will provide an airspace between reflectix and most of the outer vehicle wall and ceiling.  May even put 2 layers of reflectix.  How effective will it be???  I'll let you know in about a year.

Rodgah that!   Same with my build (moving from Hawaii to the mainland to travel in a van i dont have... And find a job ) as I'll be building in April/may.   Hope to finish it in under a month!   We're worried mainly about heat so thinking bubble wrap on van skin with reflectex and some kind of interior... Cloth or wood.   Will do a build thread at some point! 
Erik

 

[DannyB1954]

It takes very little electricity flowing through your heart for it to be lethal. Electricity always takes the path of least resistance. Being electrocuted in water means that your body has less electrical resistance than the water that surrounds you. instead of going through the water that surrounds you, it goes through you as you have less resistance than the water. Having something that conducts milliamps does not make it a good electrical conductor.
In the example of the electrical short circuit on the dock, if water was a good conductor it would have tripped the fuse or circuit breaker protecting that circuit.
Water is not a good electrical conductor. The problem being the little it does conduct is more than a human heart can take. http://hypertextbook.com/facts/2000/JackHsu.shtml