approximate volume flow rate of outdoor air needed to ventilate an office Given room volume (V) = 595.0 m^3; air changes per hour (N) = 17.5000 1/hr, determine the outdoor air volume flow rate (Q) in m^3/min.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except Q is given, so isolate Q symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for Q:

   $$Q = \dfrac{VN}{60}$$

3. Step 3

   $$List the givens: room volume (V) = 595.0 m^3, air changes per hour (N) = 17.5000 1/hr$$

4. Step 4 — Substitute the given values:

   $$Q = \dfrac{V17.5000}{60}$$

5. Step 5 — Evaluate:

   Q = 173.5\ \text{m^3/min}

6. Step 6 — Check: returning Q = 173.5 m^3/min to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 347.1 — kept a factor of two that cancels in the correct rearrangement.
• 86.7708 — dropped that same factor in the other direction.
• 190.9 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

outdoor air volume flow rate calculation for indoor air quality design Given air changes per hour (N) = 12.0000 1/hr; outdoor air volume flow rate (Q) = 256.0 m^3/min, determine the room volume (V) in m^3.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except V is given, so isolate V symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for V:

   $$V = \dfrac{60Q}{N}$$

3. Step 3 — List the givens: air changes per hour (N) = 12.0000 1/hr, outdoor air volume flow rate (Q) = 256.0 m^3/min.

4. Step 4 — Substitute the given values:

   $$V = \dfrac{60256.0}{12.0000}$$

5. Step 5 — Evaluate:

   V = 1280\ \text{m^3}

6. Step 6 — Check: returning V = 1,280 m^3 to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 2,560 — kept a factor of two that cancels in the correct rearrangement.
• 640.0 — dropped that same factor in the other direction.
• 1,408 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

ventilation outdoor air volume flow rate for a classroom Given room volume (V) = 663.0 m^3; outdoor air volume flow rate (Q) = 262.8 m^3/min, determine the air changes per hour (N) in 1/hr.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except N is given, so isolate N symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for N:

   $$N = \dfrac{60Q}{V}$$

3. Step 3 — List the givens: room volume (V) = 663.0 m^3, outdoor air volume flow rate (Q) = 262.8 m^3/min.

4. Step 4 — Substitute the given values:

   $$N = \dfrac{60262.8}{663.0}$$

5. Step 5 — Evaluate:

   $$N = 23.7828\ \text{1/hr}$$

6. Step 6 — Check: returning N = 23.7828 1/hr to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 47.5656 — kept a factor of two that cancels in the correct rearrangement.
• 11.8914 — dropped that same factor in the other direction.
• 26.1611 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

approximate volume flow rate of outdoor air needed to ventilate an office Given room volume (V) = 1,579 m^3; air changes per hour (N) = 9.5000 1/hr, determine the outdoor air volume flow rate (Q) in m^3/min.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except Q is given, so isolate Q symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for Q:

   $$Q = \dfrac{VN}{60}$$

3. Step 3

   $$List the givens: room volume (V) = 1,579 m^3, air changes per hour (N) = 9.5000 1/hr$$

4. Step 4 — Substitute the given values:

   $$Q = \dfrac{V9.5000}{60}$$

5. Step 5 — Evaluate:

   Q = 250.0\ \text{m^3/min}

6. Step 6 — Check: returning Q = 250.0 m^3/min to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 500.0 — kept a factor of two that cancels in the correct rearrangement.
• 125.0 — dropped that same factor in the other direction.
• 275.0 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

outdoor air volume flow rate calculation for indoor air quality design Given air changes per hour (N) = 14.5000 1/hr; outdoor air volume flow rate (Q) = 88.6000 m^3/min, determine the room volume (V) in m^3.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except V is given, so isolate V symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for V:

   $$V = \dfrac{60Q}{N}$$

3. Step 3 — List the givens: air changes per hour (N) = 14.5000 1/hr, outdoor air volume flow rate (Q) = 88.6000 m^3/min.

4. Step 4 — Substitute the given values:

   $$V = \dfrac{6088.6000}{14.5000}$$

5. Step 5 — Evaluate:

   V = 366.6\ \text{m^3}

6. Step 6 — Check: returning V = 366.6 m^3 to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 733.2 — kept a factor of two that cancels in the correct rearrangement.
• 183.3 — dropped that same factor in the other direction.
• 403.3 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

ventilation outdoor air volume flow rate for a classroom Given room volume (V) = 577.0 m^3; outdoor air volume flow rate (Q) = 216.3 m^3/min, determine the air changes per hour (N) in 1/hr.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except N is given, so isolate N symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for N:

   $$N = \dfrac{60Q}{V}$$

3. Step 3 — List the givens: room volume (V) = 577.0 m^3, outdoor air volume flow rate (Q) = 216.3 m^3/min.

4. Step 4 — Substitute the given values:

   $$N = \dfrac{60216.3}{577.0}$$

5. Step 5 — Evaluate:

   $$N = 22.4922\ \text{1/hr}$$

6. Step 6 — Check: returning N = 22.4922 1/hr to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 44.9844 — kept a factor of two that cancels in the correct rearrangement.
• 11.2461 — dropped that same factor in the other direction.
• 24.7414 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

approximate volume flow rate of outdoor air needed to ventilate an office Given room volume (V) = 1,452 m^3; air changes per hour (N) = 8.5000 1/hr, determine the outdoor air volume flow rate (Q) in m^3/min.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except Q is given, so isolate Q symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for Q:

   $$Q = \dfrac{VN}{60}$$

3. Step 3

   $$List the givens: room volume (V) = 1,452 m^3, air changes per hour (N) = 8.5000 1/hr$$

4. Step 4 — Substitute the given values:

   $$Q = \dfrac{V8.5000}{60}$$

5. Step 5 — Evaluate:

   Q = 205.7\ \text{m^3/min}

6. Step 6 — Check: returning Q = 205.7 m^3/min to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 411.4 — kept a factor of two that cancels in the correct rearrangement.
• 102.9 — dropped that same factor in the other direction.
• 226.3 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

outdoor air volume flow rate calculation for indoor air quality design Given air changes per hour (N) = 9.0000 1/hr; outdoor air volume flow rate (Q) = 120.4 m^3/min, determine the room volume (V) in m^3.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except V is given, so isolate V symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for V:

   $$V = \dfrac{60Q}{N}$$

3. Step 3 — List the givens: air changes per hour (N) = 9.0000 1/hr, outdoor air volume flow rate (Q) = 120.4 m^3/min.

4. Step 4 — Substitute the given values:

   $$V = \dfrac{60120.4}{9.0000}$$

5. Step 5 — Evaluate:

   V = 802.7\ \text{m^3}

6. Step 6 — Check: returning V = 802.7 m^3 to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 1,605 — kept a factor of two that cancels in the correct rearrangement.
• 401.3 — dropped that same factor in the other direction.
• 882.9 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

ventilation outdoor air volume flow rate for a classroom Given room volume (V) = 309.0 m^3; outdoor air volume flow rate (Q) = 31.5000 m^3/min, determine the air changes per hour (N) in 1/hr.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except N is given, so isolate N symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for N:

   $$N = \dfrac{60Q}{V}$$

3. Step 3 — List the givens: room volume (V) = 309.0 m^3, outdoor air volume flow rate (Q) = 31.5000 m^3/min.

4. Step 4 — Substitute the given values:

   $$N = \dfrac{6031.5000}{309.0}$$

5. Step 5 — Evaluate:

   $$N = 6.1165\ \text{1/hr}$$

6. Step 6 — Check: returning N = 6.1165 1/hr to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 12.2330 — kept a factor of two that cancels in the correct rearrangement.
• 3.0583 — dropped that same factor in the other direction.
• 6.7282 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air

approximate volume flow rate of outdoor air needed to ventilate an office Given room volume (V) = 443.0 m^3; air changes per hour (N) = 19.5000 1/hr, determine the outdoor air volume flow rate (Q) in m^3/min.

Start with the thinking

• The governing relation printed in this handbook section is Approximate Volume Flow Rate of Outdoor Air.
• Everything except Q is given, so isolate Q symbolically first — never rearrange after the numbers are in.
• Tabulate each given with its unit and confirm the units are consistent with the relation before substituting.
• The approximate volume flow rate of outdoor air needed for ventilation is estimated from room volume and air changes per hour.

Step-by-step solution

1. Step 1 — State the governing relation:

   $$Q = \dfrac{V \times N}{60}$$

2. Step 2 — Rearrange symbolically for Q:

   $$Q = \dfrac{VN}{60}$$

3. Step 3

   $$List the givens: room volume (V) = 443.0 m^3, air changes per hour (N) = 19.5000 1/hr$$

4. Step 4 — Substitute the given values:

   $$Q = \dfrac{V19.5000}{60}$$

5. Step 5 — Evaluate:

   Q = 144.0\ \text{m^3/min}

6. Step 6 — Check: returning Q = 144.0 m^3/min to

   $$Q = \dfrac{V \times N}{60}$$

   reproduces the given quantities, and both sides carry the same units.

Why the other options are there

• 288.0 — kept a factor of two that cancels in the correct rearrangement.
• 71.9875 — dropped that same factor in the other direction.
• 158.4 — rounded an intermediate value before the final step.

Reference: FE Handbook — Approximate Volume Flow Rate of Outdoor Air