HVAC Calculation: Learn About CFM, BTU/HR, TMBH & SMBH

  • Thread starter Thread starter arun.p
  • Start date Start date
  • Tags Tags
    Calculation Hvac
Click For Summary
SUMMARY

The discussion focuses on HVAC calculations, specifically the determination of CFM (Cubic Feet per Minute) and BTU/HR (British Thermal Units per Hour). A ton of cooling is defined as 12,000 BTU/HR. The terms TMBH (Total MBH) and SMBH (Sensible MBH) are clarified, with TMBH representing total capacity in MBH (1 MBH equals 1,000 BTU/HR) and SMBH indicating the portion of capacity related to temperature change. Effective HVAC capacity calculations often utilize software or psychrometric charts for accurate results.

PREREQUISITES
  • Understanding of HVAC terminology, including CFM and BTU/HR
  • Familiarity with psychrometric charts for temperature and humidity calculations
  • Knowledge of HVAC load calculation software
  • Basic principles of thermodynamics related to heating and cooling
NEXT STEPS
  • Research HVAC load calculation software options
  • Learn how to use psychrometric charts for HVAC applications
  • Study the principles of thermodynamics in HVAC systems
  • Explore detailed explanations of TMBH and SMBH in HVAC design
USEFUL FOR

This discussion is beneficial for HVAC engineers, MEP professionals, and anyone involved in the design and calculation of heating and cooling systems.

arun.p
Messages
1
Reaction score
0
Dear all
I am working in MEP field but no experience so I need your helps how find out an area cfm calculation and what is the ton of Ac given, what is the power how to find this calculation ..
BTU/HR - British Thermal Unit /Hr.

CFM - Cubic Feet per Minite

TMBH - ?

SMBH - ?

what is mean by TMBH and SMBH ?
 
Engineering news on Phys.org
Welcome to PF.

If you're working in the HVAC field, don't you have a more experienced engineer to mentor you? There is no other effective way to become an HVAC engineer. Anyway...

The capacity required (CFM at a certain temperature) is usually calculated using software for the internal and skin (walls, windows) load and fraction of fresh air and its temperature. Unless it is 100% outside air and a high volume (like for a lab), then it is just calculated using a psychrometric chart.

A ton of cooling is 12,000 BTU/hr

TMBH is total MBH (MBH is 1000 BTU/hr)
SMBH is sensible MBH (the part of the capacity related to temperature change, not condensation of water.
 

Similar threads

How to calculate heat transfer?
  • · Replies 11 ·
Replies
11
Views
3K
Calculating Home Heat Losses for Window Replacement | 30% Tax Credit Ends Soon!
  • · Replies 23 ·
Replies
23
Views
7K
Calculating the effectiveness of a Radiator and Fan Combination
  • · Replies 2 ·
Replies
2
Views
8K
Low volumetric flow rate measurement
  • · Replies 2 ·
Replies
2
Views
2K
Calculating CFM for Compressed Air Venting Down to Atmospheric Pressure
  • · Replies 4 ·
Replies
4
Views
11K
Looking for input of other peoples opinions on the relationship of CFM and PSI?
  • · Replies 6 ·
Replies
6
Views
4K
Undergrad BTU Calculation for a fireplace-based heater
  • · Replies 2 ·
Replies
2
Views
1K
HVAC - help designing dehumidification system
  • · Replies 2 ·
Replies
2
Views
5K
Thermal Resistance due to Convection Heat Transfer
  • · Replies 4 ·
Replies
4
Views
4K
Calculating time for object to reach ambient temperature in an oven
  • · Replies 4 ·
Replies
4
Views
45K