HVAC BROS

  🧠 ASHRAE-Based HVAC Design MCQs 🌬️ ASHRAE 62.1 & 62.2 – Ventilation and IAQ ASHRAE 62.1 defines minimum outdoor air ventilation rates based on: Building height Occupancy type and area HVAC system type Climate zone ✔️ Answer: b. Occupancy type and area Ventilation Rate Procedure uses people + area components. ASHRAE 62.2 applies primarily to: Hospitals Commercial buildings Residential dwellings Industrial facilities ✔️ Answer: c. Residential dwellings Focuses on IAQ in low-rise homes and apartments. ASHRAE 62.1 recommends CO₂ levels not exceed: 700 ppm 1000 ppm 1200 ppm 1500 ppm ✔️ Answer: b. 1000 ppm Relative to outdoor air, for acceptable IAQ. Ventilation effectiveness in ASHRAE 62.1 is highest when: Supply and return are on the same wall Air is supplied near the ceiling and returned low Air is supplied low and returned high Air is recirculated only ✔️ Answer: c. Air is supplied low and returned high Promotes displacement ventilatio...

HVAC Design Engineer Interview MCQs – Answers & Explanations HVAC Design Engineer Interview MCQs – Answers & Explanations A curated set of 75+ advanced questions covering fundamentals, loads, duct/piping design, hydronics, VRF, controls, energy, codes, acoustics, and commissioning. Fundamentals and thermodynamics 15 questions 1. What is the primary law governing heat transfer in HVAC systems? a. Newton’s Law b. Pascal’s Law c. Fourier’s Law d. Bernoulli’s Law Answer & explanation Answer: c. Fourier’s Law. Governs conductive heat transfer, central to envelope and insulation calculations. 2. Which type of heat changes the temperature of a substance without changing its phase? a. Latent heat b. Sensible heat c. Hidden heat d. Specific heat Answer & explanation Answer: b. Sensible heat. Used in sensible ...

Complete HVAC Formula Guide — expanded sections, worked examples. Contents Cooling and heating equations R‑values and U‑values Water system equations (hydronic) Air change rate (ventilation) Mixed air temperature (air mixing) Ductwork equations and equivalent round size Fan laws Pump laws and NPSH Condensate, humidification and humidifier heat gain Expansion tanks (hydronic) Air balance and economizer mass balance Efficiencies, COP and EER Cooling towers and heat exchangers (range/approach) Moisture condensation on glass (surface temperature) Electricity (power calculations) Transient heating (loading docks / vestibules) Refrigeration room ventilation (refrigerant leak control) Flat‑oval duct formulas and equivalent diameter Pipe expansion allowances (L, Z, U loops) Steam and condensate (mass & pipe sizing) Psychrometrics (humidity ratio, enthalpy) Pools and domestic water heater sizing Relief valve sizing and venting rules Steel pipe geometry & unit...