HVAC Services
Get Your Estimate
At NW Mechanical, we're always ready to take your call! Give us a call at (206) 900-9231 or fill out the form below to contact one of our team members.
"*" indicates required fields
Indoor Air Quality in Seattle & Eastside
What Actually Affects the Air in a Seattle Home
Indoor air quality gets talked about as though it is one product you can buy. It is not. It is the result of three separate things working together: what you filter out, how much moisture is in the air, and how much fresh air the house gets. Fix one and ignore the others and you will not notice much difference.
Our climate makes this specific. Long shut-up winters, high outdoor humidity, and summer wildfire smoke that now recurs rather than surprises.
Filtration
Removing particulate — dust, pollen and smoke — from the air moving through the system. The right filter depends on what your equipment can handle.
Humidity
Air that is too dry is uncomfortable; air that is too damp causes condensation and mould. Both are controllable.
Fresh air
A tight modern home needs deliberate air exchange. Filtration cannot substitute for ventilation.
The Three Local Problems
Wildfire smoke
Smoke episodes are now a recurring feature of Puget Sound summers — some years mild, some severe — and they are the one time of year when filtration matters more than anything else. The standard one-inch fibreglass filter is rated MERV 1 to 4; it protects the equipment, not you. Fine particulate needs MERV 13. Getting there without straining the blower is the whole job, and that last part is where most upgrades go wrong.
Winter damp
From roughly October to April the house is shut. Moisture from cooking, showering and drying laundry accumulates, and in a well-sealed home it has nowhere to go. Condensation on windows and musty rooms are the visible result. This is a ventilation problem far more often than it is a filtration problem.
Dry air in winter
A cold spell drives indoor humidity down, and not because the furnace dries the air. Cold outdoor air holds almost no moisture, so every cubic foot that leaks in gets warmed and turns dry. That is what causes static, dry skin and cracked woodwork. Whole-home humidification addresses it at the system rather than with portable units in individual rooms.
WORTH KNOWING
Fitting the highest-rated filter you can buy is not automatically an upgrade. A filter too restrictive for your blower reduces airflow, which costs capacity and leaves rooms uneven. What matters is filter area and depth, not the MERV number alone — a four-inch media cabinet can deliver MERV 13 with less resistance than a one-inch MERV 11.
Where to Start
If you are not sure which of the three is your issue, the symptom usually tells us. Dust and smoke concerns point at filtration. Condensation, damp and musty smells point at ventilation. Static, dry skin and shrinking timber point at humidity. Several at once is common, and worth looking at as one system rather than three purchases.
For a fuller walk through the year, our year-round guide to indoor air quality in Seattle and on the Eastside covers what tends to matter in each season.
Frequently Asked Questions
Will a better filter help with wildfire smoke?
Yes, provided it is matched to your system. Fine particulate needs a proper media filter rather than a basic one-inch panel, but the filter has to be one your blower can actually pull air through.
Do I need an air purifier as well?
A well-filtered ducted system does most of the work. During a smoke event the EPA recommends adding a portable HEPA unit in one room, a clean room, because your furnace only filters while the blower is running.
Is my damp bathroom an air quality issue?
It is a ventilation issue, which is part of air quality. Filtration will not touch it. Extraction that is correctly sized and vented outside will.
Can you assess the whole house rather than sell me a product?
That is how we prefer to work. Symptoms point to causes, and the cause determines what is actually worth spending money on.
Licensed, Bonded and Insured
Family-owned, based in Woodinville, serving Seattle and the Eastside.
WA CONSTRUCTION
NORTHM*799CA
WA ELECTRICAL
NORTHM*794CF
WA PLUMBING
NORTHM*760NG
UBI
604 682 203
Not Sure Which One Is Your Problem?
Tell us the symptoms and we will work out where the fix actually belongs.
How can we help you?
Our Values & Benefits
See How We're Different
Emergency Service Available 24/7
*For Service Partner Plan Members
Tailored Solutions for Home Efficiency & Comfort
