Cooling air from pump....

Vumar

Well-Known Member
Yes however my expertise is in construction specifically finish work and estimates/prints. I have a basic knowledge of how vehicles work... however I wouldn't call myself a mechanic.
 

ttystikk

Well-Known Member
Air pumps are called pumps because they are not compressors...

Theres a big difference.
Because air is a gas, it gets compressed- and heated- as it's pumped. Water is an incompressible fluid, so pumping it does not heat it to nearly the same extent.
 

ttystikk

Well-Known Member
Ok then...does a fan compress air to move it
It both raises pressure beneath and reduces pressure above the airfoil, just like the crude wing it is. This is the mechanism of physics by which it actually imparts energy to the air to move it.
 

redi jedi

Well-Known Member
Because air is a gas, it gets compressed- and heated- as it's pumped. Water is an incompressible fluid, so pumping it does not heat it to nearly the same extent.
It doesnt get compressed enough to heat up...waving your hand through the air is slightly compressing the air directly in front of your hand but it doesnt get hot...does it
 

whitebb2727

Well-Known Member
It both raises pressure beneath and reduces pressure above the airfoil, just like the crude wing it is. This is the mechanism of physics by which it actually imparts energy to the air to move it.
Word.

Oh and the egine remark is funny. An engine is a air pump. I was looking through airframe and powerplant book the other day. The powerplant book has gas, diesel, and jet engines in it. It speaks of the combustion engine as an air pump.
 

redi jedi

Well-Known Member
Word.

Oh and the egine remark is funny. An engine is a air pump. I was looking through airframe and powerplant book the other day. The powerplant book has gas, diesel, and jet engines in it. It speaks of the combustion engine as an air pump.
Exactly...so what position are the valves in during the compression strokeÉ
 

redi jedi

Well-Known Member
It both raises pressure beneath and reduces pressure above the airfoil, just like the crude wing it is. This is the mechanism of physics by which it actually imparts energy to the air to move it.
Go look at any fan in your house and tell tell me if the blades have an aerofoilÉ
 

ttystikk

Well-Known Member
Word.

Oh and the egine remark is funny. An engine is a air pump. I was looking through airframe and powerplant book the other day. The powerplant book has gas, diesel, and jet engines in it. It speaks of the combustion engine as an air pump.
@redi jedi this is an excellent example I can use to explain;

A racing engine has a ten to one compression ratio, correct? It's compressing air, yes? Boyle's (I think it's his name) gas law says that anytime a gas is compressed, it's heated by a predictable amount.

Waving a hand in front of your face isn't composing it much, so the heating effect is minimal. In the other hand, engines and superchargers comes air a great deal, creating much more heat in the process. It's this heat, in fact, that an intercooler is designed to dissipate.

I hope that helps.
 

ttystikk

Well-Known Member
Go look at any fan in your house and tell tell me if the blades have an aerofoilÉ
Every blade IS an airfoil. Maybe not one that belongs on the Concorde, but it's a crude rotary airfoil that fits the definition just fine. In water, its counterpart is a screw or prop.
 

redi jedi

Well-Known Member
@redi jedi this is an excellent example I can use to explain;

A racing engine has a ten to one compression ratio, correct? It's compressing air, yes? Boyle's (I think it's his name) gas law says that anytime a gas is compressed, it's heated by a predictable amount.

Waving a hand in front of your face isn't composing it much, so the heating effect is minimal. In the other hand, engines and superchargers comes air a great deal, creating much more heat in the process. It's this heat, in fact, that an intercooler is designed to dissipate.

I hope that helps.
You dont get it....the engine makes compression because the piston is moving into a finite space (the intake and exhaust valves are closed)...if those valves were open..theres no compression...like an air pump
 
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redi jedi

Well-Known Member
Every blade IS an airfoil. Maybe not one that belongs on the Concorde, but it's a crude rotary airfoil that fits the definition just fine. In water, its counterpart is a screw or prop.
NO its not...a fan moves air like a propeller moves water..which is a screw..not an aerofoil
 

ttystikk

Well-Known Member
You dont get it....the engine makes compression because the piston in moving into a finite space (the intake and exhaust valves are closed)...if those valves were open..theres no compression...like an air pump
Ah but this is why it's the perfect example! The fact that it CAN compress the air is exactly why it's a pump. Doing so happens to heat air, because it's a gas.

Water, by way of stark contrast, is incompressible. Stick much of that in the motor and it will knock the heads off!
 

firsttimeARE

Well-Known Member
So my air pump that uses a piston isn't compressing anything?
:roll:

Anyone have an average idea of how many BTUs I would need to comfortably cool a grow room thats 4x8 with 2,000 watts of HID (air cooled lights w/chiller for rdwc)? Assuming temperature outside is only 80-85 degrees. I need a portable A/C but don't have experience with brands or design types.


@firsttimeARE , @ttystikk , @dbkick , @jijiandfarmgang - What're you guys running for lights, AC, and chillers?
4000btu per 1k. get a 12-14kbtu
 
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