imperical formula

[adcris_1]

hello good day...... what is the imperical formula in solving the tonnage requirement of a building with a given floor area and floor to ceiling height of 3 meters. thank you and more power

[anindo]

hi everybody.... good morning..... can anybody let me know the method of calculating the "COP" of a "CLOSED" as well as "OPEN" system.....

regards

[adcris_1]

good day...does anyone knows what is the required ton of refrigeration needed for a volume of 1 cu.m. or an area of 1 sq.m? ( empirical value)
thanks.......

[nike123]

good day...does anyone knows what is the required ton of refrigeration needed for a volume of 1 cu.m. or an area of 1 sq.m? ( empirical value)
thanks.......

Heat load doesn't depend directly on volume or surface of building.
It depend on heat gain from surrounding walls, ceiling, floor, windows, quantity and quality of fresh air, number of occupants end heat generated from different heat sources in rooms.
You need to know all these data, and then you could calculate required ton of refrigeration needed.

[adcris_1]

thanks nike 123...... thats exactly some of the requirements to get the cooling load of the space to be conditioned. What i mean is that can we used some data which is not written in the book; like 14 square meter/ton or 150watts/cu.m. to get the required tonnage of the space to be conditioned?

[nike123]

thanks nike 123...... thats exactly some of the requirements to get the cooling load of the space to be conditioned. What i mean is that can we used some data which is not written in the book; like 14 square meter/ton or 150watts/cu.m. to get the required tonnage of the space to be conditioned?

That is called "rule of thumb", and rule of thumb doesnt take in consideration all above said. They are mainly used in spaces with common building practice and by experienced installer could be well on right track.
As you know, there is lot of different building practices and climatic conditions for any rule of thumb to be of universal value.
I know, for my town, in some new buildings and flats oriented at South that 120W/m^2 is good rule of thumb, but that could be pretty much off for some other house 50m from that flat (or at same building like top floor flat or basement flat). Also, flat oriented at North-East or North-West could need much more heating capacity then that oriented to South. For that same building my rule of thumb is, in that case, 150W/m^2.

[adcris_1]

nike 123..... thank you for your explanation about the rule of a thumb.

[nike123]

nike 123..... thank you for your explanation about the rule of a thumb.

I am glad to be of help!

[nike123]

This thread is totally of topic!
The original poster has newer got any answer and this is gone in different direction!

[nike123]

hi everybody.... good morning..... can anybody let me know the method of calculating the "COP" of a "CLOSED" as well as "OPEN" system.....

regards

Please, define closed and open system or give some example!

Generally COP is is relationship of useful heat supplied by condenser and work consumed by compressor:

This is second result when you type COP in Google search box.
http://tinyurl.com/65g3zo

[US Iceman]

Rules-of-thumb are OK to use if you want to verify the installed capacity or want to do a sanity check to quickly develop some concepts for troubleshooting. They should not however be used for design purposes.

As nike123 pointed out the rules-of-thumb are usually based on some general conditions to be valid. If the specific operating conditions exceed the assumptions used in the rule-of-thumb you can have problems.