Air Ventilation Solutions in Seattle & Eastside

Fresh Air Is a System, Not an Open Window

New homes in this region have got considerably tighter over the past two decades. Washington has required blower-door testing on new construction since 2009, and the current residential code caps a dwelling at 4.0 air changes per hour. Older houses that have been re-sided, re-windowed or air-sealed have often followed. A tight house holds heat well. It also holds moisture, cooking odours, and whatever else is in the air.

In a climate where the house is shut for eight months of the year, ventilation stops being optional. It is how a well-sealed home stays comfortable rather than stuffy and damp.

What ventilation actually does

It brings a controlled amount of outdoor air in and moves stale indoor air out, on purpose and at a known rate, rather than leaving it to chance. Done properly it manages humidity, clears cooking and bathroom moisture before it reaches the walls, and keeps the air in a closed-up house from going flat.

The Moisture Problem

A family of four puts roughly two to four gallons of water into the air every day just by living — showering, cooking, laundry, breathing. In a house that no longer leaks air freely, that moisture has nowhere to go. It condenses on the coldest surfaces it can find, which is usually a window or an exterior wall, and that is where the trouble starts.

An extractor fan that is undersized, ducted badly, or venting into the attic instead of outside will not solve it. Neither will opening a window in January. This is what ventilation systems are for.

Ventilation and Washington Code

Washington requires a ventilation system in every new dwelling. The state residential code is explicit about it: WAC 51-51-1505, Section M1505.4 states that each dwelling unit shall be equipped with a ventilation system, sets minimum outdoor airflow rates by floor area and bedroom count, and accepts a balanced system designed and commissioned to ASHRAE 62.2 as an alternative path.

On additions and alterations the new work has to meet current code, though how far that reaches back into the existing house depends on the scope and on your local building department. Either way, we handle ventilation as part of the mechanical design rather than leaving it to be sorted out at inspection.

Ventilation Systems and Where They Fit

Neither recovery type is automatically right for this climate. An HRV suits a house with a moisture problem — a wet crawlspace, heavy occupancy, persistent window condensation. An ERV suits a tight house that already runs dry in winter, which is increasingly common in newer construction. We measure before we specify rather than defaulting to one.

How We Approach It

Ventilation only works when it is sized to the house and installed so the air actually goes where it is supposed to. That means calculating the rate the home needs, routing ducts properly, and terminating them outside. A well-specified unit connected to poor ductwork performs like a poor unit.

Because we design and install the duct distribution as well as the equipment, the ventilation side is not bolted on afterwards by someone who did not see the rest of the system.

Frequently Asked Questions

Licensed, Bonded and Insured

Family-owned, based in Woodinville, serving Seattle and the Eastside.