I really need an answer for this as soon as possible. thanks!
-
This applies whenever there is a temperature gradient in the air. If the temperature in a room is exactly the same everywhere there will be no density gradients and the statement is not applicable.
-
I would like this to add at my question above. - air-conditioned room, such as an air-conditioned small bedroom.
Report Abuse
-
In response to The Cool Freak, first of all...great explanation of the refrigeration cycle in general.
Comments:
1. Yes it is *like* a Carnot engine, but not quite. The best, most expensive, and most impractical to build refrigeration system would be a reverse Carnot cycle. BUT, we've got a realistic design and production budget, so we don't do as well as that. The vapor-compression refrigeration cycle is closer to a reverse Rankine cycle.
2. Some air conditioners actually *do* draw in air from the outside. Seldom ever is this done in household applications, but in industrial and commercial applications it can be quite preferred. In general, when this is done, there is usually a mixing of interior air and outside air, to reduce the duty of the refrigeration cycle.
----------------------
Yes. That is why it is most optimal to place air conditioner louvers as high as possible in the room.
Heating louvers you want to place as low as possible.
If you do the opposite (which sometimes needs to be done, to minimize excess ductwork), what will happen is that you will stagnate the pockets of air differentially, so that you have a zone of hot air on the top and a zone of cold air at the bottom. This hinders future flow from the louvers.
If minimizing ductwork is part of your HVAC design goal, what you must do, is evaluate the weather conditions of the site. Make predictions of the daily fuel consumption of the heater and electrical energy consumption of the air conditioner based upon the annual temperature and humidity. Compare the price of each, assuming the same energy price ratio remains throughout the future. Figure whether it is a heating dominant region or a cooling dominant region. Often times, it is already done for you, and is documented in architectural and HVAC handbooks.
Comments:
1. Yes it is *like* a Carnot engine, but not quite. The best, most expensive, and most impractical to build refrigeration system would be a reverse Carnot cycle. BUT, we've got a realistic design and production budget, so we don't do as well as that. The vapor-compression refrigeration cycle is closer to a reverse Rankine cycle.
2. Some air conditioners actually *do* draw in air from the outside. Seldom ever is this done in household applications, but in industrial and commercial applications it can be quite preferred. In general, when this is done, there is usually a mixing of interior air and outside air, to reduce the duty of the refrigeration cycle.
----------------------
Yes. That is why it is most optimal to place air conditioner louvers as high as possible in the room.
Heating louvers you want to place as low as possible.
If you do the opposite (which sometimes needs to be done, to minimize excess ductwork), what will happen is that you will stagnate the pockets of air differentially, so that you have a zone of hot air on the top and a zone of cold air at the bottom. This hinders future flow from the louvers.
If minimizing ductwork is part of your HVAC design goal, what you must do, is evaluate the weather conditions of the site. Make predictions of the daily fuel consumption of the heater and electrical energy consumption of the air conditioner based upon the annual temperature and humidity. Compare the price of each, assuming the same energy price ratio remains throughout the future. Figure whether it is a heating dominant region or a cooling dominant region. Often times, it is already done for you, and is documented in architectural and HVAC handbooks.
12
keywords: and,hot,air,conditioned,cold,applies,Does,rises,quot,sinks,in,an,term,room,the,Does the term "hot air rises and cold air sinks" applies in an air conditioned room