In this solo episode, Chelsey, BPA Partner at MWB Engineering, breaks down the ten most common MEP (Mechanical, Electrical, and Plumbing) misconceptions she and the team regularly see on job sites. From oversizing HVAC equipment to underestimating return air paths, plumbing venting, and commissioning, Chelsey dives into how these recurring assumptions can compromise comfort, efficiency, and compliance. Whether you’re an architect, contractor, or owner, this episode will help you better coordinate and communicate on your next project — and avoid costly mistakes before they happen.

Key Takeaways:

Bigger HVAC equipment isn’t better: Oversizing causes short cycling, humidity problems, and equipment failure

Return air pathways matter: Proper sizing and routing ensure comfort and performance

Supply air isn’t fresh air: Outdoor air must be introduced intentionally per code

Panel space doesn’t mean panel capacity: Load calculations are still essential

Extending circuits isn’t always safe: Voltage drop and wire sizing can cause equipment failure

Plumbing venting is non-negotiable: Poor venting leads to odors, failures, and inspection issues

Hot water systems must be balanced: Without balancing, expect long waits and scalding risks

Sprinkler heads can’t go just anywhere: Head spacing and type affect life safety compliance

Ducts and pipes need priority in design: Leaving them last causes field issues and inefficiencies

Controls and commissioning aren’t optional: Even perfect systems won’t function without proper tuning and training

Timeline Summary:

[00:00:00] Introduction to MEP misconceptions and their impact on building performance

[00:01:00] Misconception #1: Bigger HVAC equipment solves everything

[00:03:00] Misconception #2: Return air doesn’t matter

[00:05:00] Misconception #3: Supply air equals fresh air

[00:08:00] Misconception #4: Available panel space equals capacity

[00:11:00] Misconception #5: Extending a circuit is always fine

[00:13:00] Misconception #6: Plumbing venting is flexible

[00:14:00] Misconception #7: Hot water systems don’t need balancing

[00:16:00] Misconception #8: Sprinkler heads can be placed anywhere

[00:18:00] Misconception #9: MEP can squeeze into leftover space

[00:20:00] Misconception #10: Controls, sensors, and commissioning are optional

[00:23:00] Final thoughts on communication, coordination, and engineer involvement