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

Question 8 of 14: HRV Model Selection for the Classroom

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 2.4: HRV Model Selection for the Classroom (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. Required outdoor air rate (Question 2.3) = 688.3 m³/hr. Compare against each model's maximum rated capacity.

1. Compare to the largest available unit. Even the largest model, VC5BAB027, tops out at 450 m³/hr — well below the required 688.3 m³/hr. $$450 < 688.3$$
2. Conclusion. $$\boxed{\text{No single listed HRV model can supply the classroom's required outdoor air}}$$

Final Result

Answer: (e) None of these three modes is sufficient

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