24-Bld-A4 Building Environmental Control Systems · May 2017

Question 5 of 14: Residential Ventilation Flow Rate

Nivaar worked solution (AI-drafted; not reviewed by a licensed engineer)

Notes on this paper

National Exams May 2017 — 07-Bld-A4, Building Environmental Control Systems (Building Engineering). 3-hour closed-book exam: Section 1 (four 20-mark essay/calculation questions) + Section 2 (ten 2-mark multiple-choice questions).

Reference texts: ASHRAE Handbook — Fundamentals (2021 ed.); ASHRAE Standard 62.1, Ventilation for Acceptable Indoor Air Quality (2022 ed.); McQuiston, Parker & Spitler, Heating, Ventilating, and Air Conditioning: Analysis and Design (6th ed.); National Building Code of Canada 2020 (NBCC); National Energy Code of Canada for Buildings 2020 (NECB).

Question 2.1: Residential Ventilation Flow Rate (2 marks)

Question text not reproduced: the examination questions are © Engineers and Geoscientists BC. Open the official past paper (linked at the top of this page) to read the question, then follow the worked solution below.

Given/Find. Each room's volume (floor area × 2.8 m ceiling height) is ventilated at its own room-type ACH; total flow = Σ(volume × ACH). Check: the source table prints the ACH row as "2, 3, 6, 15" under column headers "Room | Bedroom | Living Room | Bathroom | Kitchen" — the leading "Room"/ "ACH (1/hr)" pair is the row LABEL, not a fifth data category, so the four numbers map to Bedroom=2, Living Room=3, Bathroom=6, Kitchen=15.

1. Compute each room's volume and required flow. Living/dining: $15\times2.8=42\ \text{m}^3$, ACH = 3 (Living Room) → $42\times3=126.0$ m³/hr. Bedroom 1: $12\times2.8=33.6$ m³, ACH = 2 → 67.2 m³/hr. Bedroom 2: $10\times2.8=28.0$ m³, ACH = 2 → 56.0 m³/hr. Bathroom: $4\times2.8=11.2$ m³, ACH = 6 → 67.2 m³/hr. Kitchen: $6\times2.8=16.8$ m³, ACH = 15 → 252.0 m³/hr.
2. Sum. $$\boxed{126.0+67.2+56.0+67.2+252.0 = 568.4\ \text{m}^3/\text{hr}}$$

Final Result

Answer: (b) 568.4 m³/hr

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