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toxic11
10-22-2011, 06:25 PM
Can someone explain me what dose btu stand for in Cooling and heating.

Paul Bee
10-22-2011, 06:47 PM
British Thermal Unit. The amount of heat energy that it takes to raise one pound of water one degree Farenheit. Wikipedia might go into more detail.

10-23-2011, 10:53 AM

Name calling isn't needed. All other post removed.

HuNGRYTeCH
10-23-2011, 01:27 PM
Paul Bee is right on the money. We use BTU's to describe heating capacity and cooling capacity. In heating we are adding BTU's to our conditioned space and in cooling we are removing BTU's from our conditioned space. This is the basis of a huge part of our industry and the BTU is widely used in America. The metric equivalent is the Joule but we don't have to worry about that, yet. When I was first trying to wrap my head around a BTU it was described to me that a BTU is about the energy in a match, it helped put it into perspective for me. So perspective a 100,000 BTU/h furnace is some what equivalent to burning 100,000 matches per hour.

timebuilder
10-23-2011, 01:44 PM
I never heard the match analogy. Neat.

Are you in a training program?

ryan1088
10-23-2011, 01:51 PM
Paul Bee is right on the money. We use BTU's to describe heating capacity and cooling capacity. In heating we are adding BTU's to our conditioned space and in cooling we are removing BTU's from our conditioned space. This is the basis of a huge part of our industry and the BTU is widely used in America. The metric equivalent is the Joule but we don't have to worry about that, yet. When I was first trying to wrap my head around a BTU it was described to me that a BTU is about the energy in a match, it helped put it into perspective for me. So perspective a 100,000 BTU/h furnace is some what equivalent to burning 100,000 matches per hour.

Love the match analogy. The thought of converting to the metric system in our trade makes my head want to explode. I don't know what I would do...I guess buy a lot of digital gauges and switch it to psi!

HuNGRYTeCH
10-23-2011, 01:52 PM
Yeah I am. I take night classes at a community college, going for an associates degree in Commecial HVAC. I learned this years ago though, before I started school when I could not wrap my head around BTU ratings.

beenthere
10-23-2011, 02:46 PM
We need more abbreviations/acronyms in HVAC, at least another 60 or so.

BTU
ASHRAE
AHRI
SH
SC
Delta T
Delta P
T
Q
GPM

We just don't have enough yet.

Remembering that BTU is British Thermal Unit wasn't the hard part. Remembering how little a pound of water is was.

ryan1088
10-23-2011, 03:17 PM
We need more abbreviations/acronyms in HVAC, at least another 60 or so.

BTU
ASHRAE
AHRI
SH
SC
Delta T
Delta P
T
Q
GPM

We just don't have enough yet.

Remembering that BTU is British Thermal Unit wasn't the hard part. Remembering how little a pound of water is was.

Work for a company that does government work and you will have all the acronyms you can stand in addition to the ones in the trade!!! Ugh, government alphabet soup...

bunny
10-24-2011, 09:01 AM
Paul Bee is right on the money. We use BTU's to describe heating capacity and cooling capacity. In heating we are adding BTU's to our conditioned space and in cooling we are removing BTU's from our conditioned space. This is the basis of a huge part of our industry and the BTU is widely used in America. The metric equivalent is the Joule but we don't have to worry about that, yet. When I was first trying to wrap my head around a BTU it was described to me that a BTU is about the energy in a match, it helped put it into perspective for me. So perspective a 100,000 BTU/h furnace is some what equivalent to burning 100,000 matches per hour.

While this might give some real life perspective as to the relative amount of heat that can be assigned to 1 Btu, I'd be very surprised if there was enough heat content in a single match to raise 1 lb of water 1*F.

Control Man
10-24-2011, 09:05 AM
I'd be very surprised if there was enough heat content in a single match to raise 1 lb of water 1*F. Let alone a match that burns for 1 hour.

bunny
10-24-2011, 09:34 AM
Actually, there is no time frame for raising a lb of water 1*F.

1 Btu is simply the quantity of heat necessary to accomplish that increase in temperature, regardless of the time it takes.

1 Ton is the amount of heat transfer necessary to convert 1 ton of water at 32*F to 1 ton of ice at 32*F, in a 24 hr period.

One Ton = 12,000 Btu/hr

ControlsInMT
10-24-2011, 10:35 AM
Depends on the size of the match!!!

Home&Marine
10-24-2011, 11:00 AM
Actually, there is no time frame for raising a lb of water 1*F.

1 Btu is simply the quantity of heat necessary to accomplish that increase in temperature, regardless of the time it takes.

1 Ton is the amount of heat transfer necessary to convert 1 ton of water at 32*F to 1 ton of ice at 32*F, in a 24 hr period.

One Ton = 12,000 Btu/hr

Looks like a lot of people forgot what they were taught in (HVAC) School?

The Match is just an example. It's not set in stone (because not all matches are the same). Like "bunny" says... No exactly what "bunny" says.

Did you forget Latent and Specific Heat too?

1 lb to water (at 32 degrees) to ice, 144 btus of cooling.

I can understand us older guys forgetting it but for a New Tech... something is wrong. (Maybe no school?)