Your House Is Sealed Tight.
Now Give It Fresh Air.
Serious Fresh Air designs, installs, commissions, and maintains Zehnder's High Performing Ventilation Systems — the Swiss-engineered standard for airtight, high-performance homes. Filtered and tempered outdoor air in every bedroom, the cool air you already paid for kept inside, and a measured commissioning report to prove it works.
Airtight Homes Don't Ventilate Themselves.
A modern envelope holds conditioned air in — and everything else with it. Cooking moisture, VOCs off new finishes and furniture, CO₂ from the people asleep in the bedrooms, pet dander, pollen, wildfire smoke. Without mechanical ventilation, none of it has anywhere to go.
The air inside is the problem
The EPA has measured indoor air carrying two to five times the pollutant concentration of outdoor air — and sometimes far more. The house you sealed for efficiency is where you and your family spend most of your life.
The ventilation is required. The ERV is the choice.
Codes built on ASHRAE 62.2 require whole-house mechanical ventilation in a new home. They do not require an ERV — a single-point fan on a timer, supply or exhaust, also complies. What that fan cannot do is filter what comes in, recover the heat going out, or leave the house sitting at neutral pressure. An ERV satisfies the same requirement and does all three.
The stakes are health, not comfort
ASHRAE attributes roughly 3.2 million deaths a year worldwide to household air pollution, tying poor indoor air to cardiovascular and respiratory illness. Ventilation is the one system in the house whose whole job is the quality of air your family breathes — and it works every hour they are home or away.
Homeowners Feel It. Builders Bank On It.
The same system solves two very different problems — a house that finally feels good to live in, and a mechanical package that passes, documents, and sells.
For Homeowners
You will notice it the first morning.
- Wake up without the stuffy-room headache — CO₂ stays low in the bedrooms all night.
- Allergy season stops at the wall instead of in your sinuses — and you will notice how much less often you are dusting.
- Balanced supply and exhaust — no drafts, no whistling returns, no doors slamming from pressure.
- Fresh air without the heating bill that normally comes with cracking a window in February.
For Builders & Developers
Ventilation that passes, documents, and sells.
- ASHRAE 62.2 and IECC ventilation compliance designed in, installed to spec, and verified on site.
- A commissioning report with measured CFM at every register — numbers for your inspector and your file.
- Supports ENERGY STAR, DOE Efficient New Homes, and Passive House ventilation requirements.
- Install it with your own HVAC crew under our supervision, or hand the whole scope to us.
We Install Exactly One Brand. Here Is Why.
Zehnder has been building energy-recovery ventilation in Switzerland since 1977, and every ComfoAir Q model carries a Home Ventilating Institute performance report — not merely advertised as efficient, but independently tested to the North American standard, certified, and published. When we hand you a performance number, someone else already checked it.
Independently certified
ComfoAir Q350 ERV, as certified by HVI
- Net heat recovery (SRE)
- 76–83%
- Total recovery (TRE)
- 65–72%
- Certified airflow
- 201 CFM to 1.0 in. w.g.
- Fan power, measured
- 28–90 W
- Sound level
- 34–52 dB(A)
Figures as certified by the Home Ventilating Institute for the ComfoAir Q350 ERV — HVI reference 2005163, certified May 2024 — and measured to CSA C439.
The heat stays, the staleness leaves
That is the whole trick of a recovery ventilator. Outgoing air hands its warmth to the incoming air through the core without the two streams ever mixing, so you get outdoor air without paying to condition it twice.
Humidity that behaves itself
Enthalpy cores move moisture as well as heat. In Texas during August the incoming air hands off much of its humidity before it ever reaches your rooms, so your air conditioner is not fighting a fresh load of damp air every hour it runs.
Filtration in stages, in both directions
Every system we install runs F7 (MERV 13) filters on the extract side as well as the supply side. The incoming filter is the one you feel; the outgoing filter protects the heat-exchange core from household dust and dander, which is what keeps recovery efficiency where it started years from now. On any unit we can add a coarse pre-filter ahead of the cabinet, so pollen, insects and construction dust are caught before they ever reach the F7 filter or the core.
Quiet enough to forget
Noise in a ventilation system is nearly always a duct problem rather than a fan problem. Zehnder duct distribution and properly sized runs keep air noise out of the bedrooms, and most clients cannot tell when the system is running.
Built to be serviced, not replaced
Washable cores and a platform Zehnder has supported for decades. This is mechanical equipment that gets serviced, not a disposable appliance you throw out.
Control from your phone
ComfoConnect lets you boost airflow for a dinner party, drop to away mode on vacation, and see when filters need changing.
Two Series. One Standard Of Install.
Zehnder builds two families of recovery ventilator and we install both. The CA series covers compact homes; the Q series carries everything from a modest house up to a small multifamily building. They overlap in a narrow band, so capacity usually settles it — and where either would work, the decision moves to how the air gets distributed, and how much you control from your phone. We pick the unit at design, off your plans.
On every system we install, either series
Zehnder · two Systems
ComfoAir CA Series
Two compact systems on five-inch duct — recovery ventilation done properly, without the extras around it.
- Airflow across the series
- 19–156 CFM
- Average top end per unit
- ≈ 124 CFM
- System Efficiency
- 85–92% Heat Recovery
- Fan power draw
- 9–143 W
How the series is built
Zehnder · three Systems
ComfoAir Q Series
One platform in three capacities, with a published third-party performance report behind every model in the range.
- Airflow across the series
- 88–353 CFM
- Average top end per unit
- ≈ 274 CFM
- System Efficiency
- 88–92% Heat Recovery
- Fan power draw
- 13–287 W
How the series is built
The rate your home actually needs comes off your plans and the room-by-room design, and we size with headroom above it for boost and duct losses. Every recovery figure on this page is PHI Heat Recovery Efficiency for the ERV variants we specify.
Sell. Install. Commission. Maintain.
A ventilation system rarely fails because the equipment quit. It fails because the duct was undersized, the airflow was never balanced, or nobody maintained the system. Every step below exists to close one of those gaps.
Design and specify it properly
Room-by-room ventilation design, coordination with your Manual J and mechanical layout, duct routing drawn on plans you receive, and the right Zehnder model with a fixed, itemized quote.
Install it the way it was drawn
The unit is set, insulated metal duct is run from outside to the machine, every connection is sealed, and registers go in where the drawing puts them. Clean rough-in that passes inspection, clean trim-out your finish trades will not have to work around.
Prove it performs, in writing
This is the step almost everyone skips. We measure airflow at every supply and return, balance the system to the design CFM, ensure system connectivity, correct anything missed, and hand over a signed commissioning report with the measured numbers for your file and your homeowners.
Keep it performing for decades
Filter reminders that actually arrive, annual airflow and efficiency checks, core cleaning, and direct access to the team that designed and commissioned it. A commissioned system that gets maintained keeps its numbers; one that is ignored does not.
Make Ventilation the Line Item That Sells the House.
Tight envelopes are not optional anymore, which means every house you build needs a ventilation answer. Choose the cheap one and you get callbacks, failed verifications, and a homeowner who says the house feels clammy and stuffy. Choose the system that will keep your homeowners breathing healthy for years.
Code, handled and documented
We calculate the ASHRAE 62.2 rate, install to that design, and verify it with measured airflow. Your inspector and your rater get verified numbers on paper instead of a fan sticker.
Points where the points count
Balanced recovery ventilation supports better HERS scores and satisfies the ventilation requirements in ENERGY STAR, DOE Efficient New Homes, and Passive House. If you are chasing a label, this is the equipment that gets you there.
Your crew or ours, installed to the design
We install the system ourselves, or come out and mentor your HVAC crew through it — on site while they set the unit and run the duct. The design, the equipment, the commissioning and the ongoing service come from us either way, and the airflow is measured before anyone signs off.
A story your sales team can actually use
Buyers glaze over at R-values. They do not glaze over at filtered, tempered fresh air delivered to every bedroom, or a house that smells alive when you walk in after a week away. That is a closing argument.
Balanced Zehnder ERV vs. supply-only ventilation
| Measure | Supply-only fan | Zehnder balanced |
|---|---|---|
| House pressure | Supply-only fanPressurizes the house, pushing the air you paid to cool out through every gap | ZehnderNeutral: supply and extract matched at commissioning |
| Filtration | Supply-only fanA coarse inlet filter at best, and only on the way in | ZehnderF7 (MERV 13) on supply and extract |
| Humidity | Supply-only fanOutdoor humidity delivered straight indoors adding latent load on the HVAC | ZehnderEnthalpy core hands moisture between the streams before air reaches the rooms |
| Stale, damp air | Supply-only fanLeft to find its own way out, through the rest of the house | ZehnderExtracted at the source in baths, kitchen, and laundry |
| Incoming air | Supply-only fanArrives at full outdoor temperature and humidity — 98°F and muggy in August | ZehnderTempered and filtered by the system before it reaches any register |
| Energy recovery | Supply-only fanNone — your HVAC conditions every cubic foot | Zehnder85–92% heat recovery, certified by the Passive House Institute (PHI) |
| Verification | Supply-only fanThe fan's rating printed on the housing | ZehnderMeasured and documented CFM at every register during the commissioning |
Spec homes, phased developments and multi-building projects get the same design-and-commission treatment as custom homes, run at whatever pace your schedule needs — send us the plan set for the whole community, and we will work it plan by plan. Equipment, labor and commissioning are quoted separately rather than bundled into one big sheet. You see exactly what each part costs, on every house.
Also from our Team
Manual J Load Calculations
Different service, same company. A Manual J is the room-by-room heating and cooling load calculation that establishes how much heating and cooling a house actually needs — the number every equipment selection should start from, whatever brand is going in.
Manual J Load Calculations are important for ensuring correct sizing, no oversizing or undersizing your HVAC.
What lands in your inbox
- Room-by-room heating and cooling loads, not a per-square-foot rule of thumb
- Sensible and latent loads broken out, so you can see where it comes from
- Every input documented — design conditions, orientation, envelope, infiltration, glazing, and ventilation
- A report formatted for permit submittal and plan review
Manual J Load Calculations only — that is the whole service, and it is why it gets done properly. Every run is a full ACCA-method model of the actual house.
Questions You Might Ask Us.
No sales script. If a Zehnder system is not the right call for your house, we will tell you that too.
Can you retrofit a house that is already finished?
Often, yes. Comfoflex and Comfotube are small-diameter and flexible, so they route through joist bays, closets, and attic runs where rigid duct will not fit.
Does this replace my HVAC or my make-up air unit?
Neither one. A Zehnder is a balanced ventilation system — not heating, not cooling, not make-up air. It runs continuously, swapping stale indoor air for filtered outdoor air and recovering the energy out of what it exhausts, while your HVAC goes on handling temperature and humidity. A make-up air unit is a different job again: it answers a large exhaust appliance, like a commercial-style range hood, by replacing that air on demand at a volume no ERV is sized to deliver. All three work alongside each other — the ERV ventilates the whole house continuously, the HVAC conditions it, and the MUA covers the spikes.
Will running fresh air all summer make the house humid?
That is the right question, and it is why an enthalpy ERV core is what we usually specify. The core hands much of the moisture in the incoming air back to the air on its way out, so you are not dropping a fresh humidity load on your air conditioner every hour. The ERV ventilates; your HVAC still does the dehumidifying.
How much maintenance do I need to do?
Filters a couple of times a year, no service call required — and the app tells you when they are filthy. Cores get cleaned periodically. If you add the pre-filter, that is the one you change most often, and it is the cheapest part in the system. If you would rather not touch it at all, we will come do it if we are able.
Is it loud? I don't want to hear air blowing all night.
It lives in the mechanical room or attic rather than the hallway, and the sound figure for the unit is listed in the equipment section above. The part that actually makes a ventilation system noisy is duct design — undersized runs, sharp transitions, no attenuation — and that is a problem we solve before anyone installs anything. Some clients forget the system is there.
Do you add additional filtration before the unit?
Yes — we install a coarse pre-filter on the intake side of any Zehnder system. It is not there to clean the air you breathe; the F7 media already does that. It is there to catch the heavy debris first — pollen, insects, lawn and road dust, drywall dust during construction — so the F7 filters last noticeably longer and the enthalpy core stays clean. A core that stays clean keeps recovering at the efficiency it was certified at, and it is the one component in the system you would least like to replace early.
Get started
Tell Us About the House.
One home, a whole subdivision, or a single load calculation — it starts the same way: we look at the plans or walk the house, then come back with a system, a number, and a timeline. No pressure and no sales script, just a straight read on what the building actually needs.
- Free quotes on Zehnder systems and Manual J load calculations alike — fixed and itemized
- Measured airflow report handed over on every ventilation job
- Installed by our crew, or by yours with us on site
- Service and maintenance from the team that designed and commissioned it