Atrium design calculation using round and rectangular grills (SI and IP units)

Objectives:

1. Atrium design calculation for rectangular grill (IP Unit)
2. Atrium design calculation for round grill (IP Unit)
3. Atrium design calculation for rectangular grill (SI Unit)
4. Atrium design calculation for round grill (SI Unit)

1. Atrium design calculation for rectangular grill (IP Unit)

Routine 4A: Preventing plug holing with rectangular inlets

Inputs as below:

Qc = 1400 btu/s

T˳ = 70˚F

m = 130.3 lb/s

V = 92600 CFM

d = 9.55 ft

ϒ = 1.0 (See notes 1,2 & 3)

Ks = 0.5 (See note 7)

a = 4 ft

b = 5 ft

N = 4 (No of inlets)

Ar = 0.50 (Suggested value)

Outputs as below:

Ts = 99.1˚F

Vmax = 29840 CFM

Ve = 23150 CFM

Smin = 9.89 ft (See note 6)

Di = 4.44 ft

d / Di = 2.15

Vi = 2315 fpm

Two checks to be done in the end to validate the outputs

1. First check: If d/Di is less than 2 that means note 4 condition is not satisfied. As in our case this ratio is greater than 2 that means our note 4 condition is satisfied 
2. Second check: If Vmax-Ve > 0 that means note 5 condition is satisfied. As in our case Vmax-Ve is greater than 0 that means our note 5 condition is satisfied 

2. Atrium design calculation for round grill (IP Unit)

Routine 4B: Preventing plug holing with round inlets

Inputs as below:

Qc = 1400 btu/s

T˳ = 70˚F

m = 130.3 lb/s

V = 92600 CFM

d = 9.55 ft

ϒ = 1.0 (See notes 1,2 & 3)

Ks = 0.5 (See note 7)

Di = 4.75 ft

N = 5 (No of inlets)

Ar = 0.50 (Suggested value)

Outputs as below:

Ts = 99.1˚F

Vmax = 29840 CFM

Ve = 18520 CFM

Smin = 8.85 ft (See note 6)

d / Di = 2.01

Vi = 2090 fpm

Two checks to be done in the end to validate the outputs

1. First check: If d/Di is less than 2 that means note 4 condition is not satisfied. As in our case this ratio is greater than 2 that means our note 4 condition is satisfied 
2. Second check: If Vmax-Ve > 0 that means note 5 condition is satisfied. As in our case Vmax-Ve is greater than 0 that means our note 5 condition is satisfied 

3. Atrium design calculation for rectangular grill (SI Unit)

Routine 4A: Preventing plug holing with rectangular inlets

Inputs as below:

Qc = 1500 KW

T˳ = 21˚C

m = 45.5 kg/s

V = 43.7 mᶾ/s

d = 3.00 m

ϒ = 1.0 (See notes 1,2 & 3)

Ks = 0.5 (See note 7)

a = 1.22 m

b = 1.52 m

N = 4 (No of inlets)

Ar = 0.50 (Suggested value)

Outputs as below:

Ts = 37.5 ˚C

Vmax = 15.35 mᶾ/s

Ve = 10.93 mᶾ/s

Smin = 2.98 m (See note 6)

Di = 1.35 m

d / Di = 2.21

Vi = 11.76 m/s

Two checks to be done in the end to validate the outputs

1. First check: If d/Di is less than 2 that means note 4 condition is not satisfied. As in our case this ratio is greater than 2 that means our note 4 condition is satisfied 
2. Second check: If Vmax-Ve > 0 that means note 5 condition is satisfied. As in our case Vmax-Ve is greater than 0 that means our note 5 condition is satisfied 

4. Atrium design calculation for round grill (SI Unit)

Routine 4B: Preventing plug holing with round inlets

Inputs as below:

Qc = 1500 KW

T˳ = 20˚C

m = 45.5 kg/s

V = 43.7 mᶾ/s

d = 3.00 m

ϒ = 1.0 (See notes 1,2 & 3)

Ks = 0.5 (See note 7)

Di = 1.45 m

N = 5 (No of inlets)

Ar = 0.50 (Suggested value)

Outputs as below:

Ts = 36.5 ˚C

Vmax = 15.38 mᶾ/s

Ve = 8.74 mᶾ/s

Smin = 2.66 m (See note 6)

d / Di = 2.07

Vi = 10.62 m/s

Two checks to be done in the end to validate the outputs

1. First check: If d/Di is less than 2 that means note 4 condition is not satisfied. As in our case this ratio is greater than 2 that means our note 4 condition is satisfied 
2. Second check: If Vmax-Ve > 0 that means note 5 condition is satisfied. As in our case Vmax-Ve is greater than 0 that means our note 5 condition is satisfied