Christian Genco

Building a Tiny House

Tiny living options #

Tent, yurt, tiny house, tiny house on wheels, converted shed, camper van

Tiny House Building Courses #

Energy Recovery Ventilator (ERV) #

Indoor air quality is extremely important to me. There are several studies showing that CO2 levels above 1,000 ppm cause measurable cognitive defects. High VOCs can cause irritation in the short term and cancer in the long term. Both VOCs and CO2 are most effectively lowered by opening a window, but doing that in Texas in the summer raises temperature (which is uncomfortable) and humidity (which is uncomfortable and in the long term can cause mold).

In Spring through Summer outdoor Texas air is also extremely high in grass pollen, which I'm currently very allergic to. (I'm also allergic to dust mites and cat dander indoor air pollutants but that can be more easily fixed with an indoor air filter.)

My solution had been opening a window and pumping in fresh outdoor air with a window fan and an air filter, which would take care of CO2, VOCs, and allergins at the expense of temperature and humidity. I was considering building some type of geothermal system that could cool their air underground before bringing it into my tiny house similar to how Earth Ships bring in cool air. However in the process of researching this tiny house build I stumbled on this magical box called an Energy/Enthalpy Recovery Ventilator, or ERV.

ERVs take in filtered fresh air from outside and stale air from inside and combine them in an ERV core to exchange temperature and humidity between them. You can take in fresh hot and humid air from outside and turn it into cool dry fresh air to be pumped into your indoor space.

Problem freakin' solved.

There seem to be several main ERV manufacturers: Broan, Fantech, Lifebreath, Honeywell, Aprilaire, Renewaire, and Panasonic.

Frustratingly, the fantech website doesn't actually let you buy any of their products, and their where to buy page seems to just list physical locations for stores that are distributers of their products. I could've gotten the Fantech SE 56 CFM for about $455 from or $700 from Amazon (it seems like Amazon won't be the best place to source tiny house building materials in the future), but the Fantech looks cheaply made on the inside.

Broan has eleven different models of ERVs that are very difficult to distinguish. Corbett Lunsford went with the Broan ERV70TE in his tiny lab.

There's also a clever tiny ERV called the Lunos E2 Heat Recovery Ventilation system that puffs air in and out from two different spots. The two units aren't connected, but they coordinate to switch which one is blowing air in and out and switch every 90 seconds. Heat and some humidity are retained in a ceramic core in each unit. This didn't seem like it would work nearly as well as a single ERV with an energy recovery core.

I ended up ordering the Panasonic Intelli-Balance 100 from

Inside out insulation #

EnergyShield is what Matt Risinger used in his home as external 'perfect wall' insulation and a radiant barrier.

Steel or Wood Framing #

Plans #

Trailer #

Attaching the frame to the trailer #

Insulation #

Fiberglass, Rock Wool, hemp wool, sheep wool, and spray foam


Lumber and Plywood #

Tongue and groove plywood


All plywood has formaldehyde in it, except Purebond. -- Tiny House’s Purebond Formaldehyde Free Plywood

90x35mm (2x4) => 70x35mm (3x2); 600mm rafter spacing => 1200mm; locate rafters over king studs and you don't need a double top plate (Tiny House University)

Make sure each piece of plywood screws into a stud on every side. For the top and bottom you might need to add extra noggin boards.

4.5mm external bracing plywood that goes all the way from the below the bottom plate (in the floor joists) to the mitre cut purlin in the roof

continuous bead of Sikaflex 11FC adhesive between bracing plywood and stud wall face, including noggins

Screws #

38mm staples to secure thin plywood

Tools #

Chop saw, Maslaw CNC?, impact driver

How to frame a tiny house #

Unified construction method

Windows #

How to install windows #

Electric blackout curtains #

House wrap #

Siding #

Roof #

Ductless minisplit AC system #

Lighting #

Fridge #

Range #

Range Hood #

Residental Central Vacuum #

Blackout blinds #