HVAC & Mechanicals

The Psychrometric Chart: 7 Minutes of BS (Building Science)


This chart explains how moisture behaves in the air as temperatures rise and fall—rainstorms, flooding, and glaciers in wall cavities are distinct possibilities.

Duct Mastic Installation Tip: Use a Workbench


It is easier to do a good job sealing ductwork when you're standing at a bench instead of crawling through a crawlspace

Residential Grow Rooms: 7 Minutes of BS


Extreme heat and humidity can drive moisture deep into framing cavities which can cause mold, rot, and structural damage

Model Remodel Show: 4 MORE Energy Efficient Construction Tips


Roof framing, window options, and a mechanical advantage add up to lower bills and a higher quality home

Model Remodel Show: Balanced Ventilation System


A simple and affordable balanced ventilation solution for small tight houses

The Right Tin Snip for the Job


Left-, right-, and straight-cutting snips with single- and compound-leverage each have their place on a jobsite

How Deep is Deep Enough to Bury Ducts?

Turns out, ducts buried under insulation actually can work to save energy and eliminate condensation inside the ducts. If you seal and insulate them first


Indoor Air Quality (IAQ): 7 Minutes of BS


Three-pronged solution to indoor pollution: Isolate, eliminate, and ventilate

A Simple Balanced Ventilation System


Two fans talk to each other to replace stale air with fresh air


Make Up Air: 7 Minutes of BS (Building Science w/a Beat)


Houses cannot expand and contract with changes in pressure like balloons can. Instead, they need paths for air to balance the pressure

Airtight Dropped Soffit for Ducts, Fans, or Can Lights


Keep mechanical equipment within the envelope to improve the quality of houses and homes

Moisture Management Design Rule 2: Manage Condensation

Condensation is when moisture in the air hits a cool enough surface to convert the vapor into water.

Mechanical Ventilation: 7 Minutes of BS


As houses are built tighter, they exchange less air between inside and outside. This saves energy, but the inside air can get stale if you don't have a fan and a plan

9 Ways to Hide a Minisplit


These mighty-mites can provide heating, cooling, and air-mixing for a well-insulated house, but they look so darned—European. It is hard for many Americans to warm up to them.  


Stack Effect: 7 Minutes of BS (#buildingscience)


Stack effect is relentless: it is always working, when you’re awake or asleep, even during blackouts. And it feeds on itself.


The Right Way (and a wrong one) To Flash a Dryer Vent

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Holes in walls amount to big walls full of holes unless you seal the hole after you make it