Whole house fan installation
Fresno nights get cool.Use them.
A whole house fan pulls that cool evening air through your house and pushes the day's heat out through the attic. In a dry climate with a big day-to-night temperature swing, it is one of the few genuinely effective ways to cut what your air conditioner has to do.
Free quotes Attic venting assessed Financing available
Why these work here
The Central Valley is close to ideal for this
Whole house fans are unimpressive in humid parts of the country, because the cool night air being pulled in is heavy with moisture and does not do much for comfort. Fresno is the opposite case. Our summer nights drop substantially from the afternoon peak, and the air is dry when they do.
That combination is exactly what a whole house fan needs. Once the outdoor temperature falls below the indoor temperature, opening a few windows and running the fan flushes the entire house with cool air in a matter of minutes, and clears the heat your attic and framing absorbed all day.
Your air conditioner starts tomorrow morning from a cooler house. That is the whole idea.
Fewer run hours also means less wear on the compressor and longer intervals between the problems that heat and run time cause. It works alongside annual maintenance rather than replacing it.
AFTERNOON
House and attic loaded with heat. The fan stays off and the AC does its job.
EVENING
Outdoor temperature drops below indoor. Windows open, AC off, fan on.
OVERNIGHT
Cool air flushes through the house and the attic empties its stored heat.
MORNING
Close up before it warms. The AC starts the day with far less to remove.
A whole house fan is not an attic fan
These get confused constantly, they do different jobs, and people frequently buy one thinking they are getting the other.
What this page is about
Whole house fan
Where it mounts
In the ceiling of your living space, drawing from inside the house.
What it moves
Air from your rooms, out through the attic and roof vents.
Windows
Must be open. They are how outside air gets in.
What you feel
The house cools directly and quickly, plus the attic clears.
When it runs
Evening and overnight, once it is cooler outside than inside.
Different product
Attic or roof fan
Where it mounts
In the roof or a gable end, drawing only from the attic.
What it moves
Attic air out, replaced by outside air through the soffit vents.
Windows
Irrelevant. It never touches the air in your living space.
What you feel
Indirect. A cooler attic reduces heat load through the ceiling.
When it runs
Usually thermostatically, during the hottest part of the day.
The simple test: if the fan cools your house by moving air you are standing in, it is a whole house fan. If it only moves air in the attic above you, it is an attic fan. Both have their place, and they are not substitutes for each other.
Read this before you buy one anywhere
Run it with the windows closed and you have a serious problem
A whole house fan moves an enormous volume of air — far more than any other fan in your home. It has to pull that air from somewhere, and if the windows are closed it will pull it down whatever paths exist.
In a house with atmospherically vented gas appliances, those paths include the flue of your water heater or furnace. The fan can reverse the draft and pull combustion gases, including carbon monoxide, back into the house instead of letting them leave through the roof.
This is not a theoretical risk and it is the single strongest reason to have one installed and commissioned by a licensed HVAC contractor rather than picked up at a big box store and fitted by someone who does not think about combustion appliances.
How we handle it
- We inventory your gas appliances and how each one vents, before recommending a fan size.
- We check draft with the fan running to confirm nothing reverses under real operating conditions.
- We size the fan to your house rather than fitting the largest one that will fit the joist bay.
- We show you how to operate it, including the window rule, before we leave.
- We recommend working CO alarms on every level regardless, which every home should have anyway.
The other thing that gets skipped
Your attic has to be able to exhale
A whole house fan pushes all that air into the attic, and the attic has to be able to get rid of it through its existing vents. Manufacturers publish a minimum net free vent area for each fan model, and it is a real number rather than a suggestion.
Fit a large fan into an attic with inadequate venting and several things go wrong at once. The fan cannot move its rated airflow, so you paid for capacity you will never get. The attic pressurizes, which can push air back down into the house through ceiling penetrations. And the fan works harder and louder for less result.
Assessing that venting is part of the quote, not something we discover during installation. Where an attic needs additional vent area, we tell you before you commit rather than afterwards.
A correctly sized fan in a badly vented attic performs worse than a smaller fan in a good one.
How you actually run one
These reward a small amount of routine. Four habits, and the first one is not optional.
1
Open windows before you switch it on
Every time, without exception. Two or three windows on the far side of the house from the fan is usually enough. This is the safety rule from the section above and it is also what makes the fan work properly rather than straining.
2
Wait until it is genuinely cooler outside
Running it while the outdoor air is still warmer than the indoor air just brings heat in. In a Fresno summer that usually means somewhere after eight or nine in the evening. A cheap outdoor thermometer settles the argument.
3
Turn the air conditioning off while it runs
They work against each other. Running both means paying to cool air that is heading straight out through the roof. Switch the thermostat off, run the fan, and turn the AC back on in the morning if you need it.
4
Close up before the heat arrives
Fan off, windows shut, blinds down on the west side, ideally before mid-morning. The point of the exercise is to bank that cool air and then keep it, which is undone by leaving the house open at eleven.
What it will and will not do
This is a complement to air conditioning, not a replacement for it. Anyone telling you otherwise is overselling.
What it does well
- Cools the house rapidly once the evening air has dropped
- Clears the heat your attic stored all day, so the ceiling stops radiating it back
- Cuts air conditioning runtime considerably in spring and fall, which shows up on the bill. What else drives a summer bill
- Uses a small fraction of the electricity a compressor does
- Flushes stale indoor air and cooking smells out quickly
What it will not do
- Cool your house on a 108-degree afternoon. That is your air conditioner's job.
- Cool below the outdoor temperature. It moves air, it does not refrigerate it.
- Help much on a night that stays hot, which does happen in a heat wave.
- Work with the house closed up, for reasons covered above.
- Suit someone with severe allergies, since it brings outdoor air in unfiltered.
If you remember the old ones
These are not your grandparents' attic fan
The whole house fans a lot of people remember were a large blade mounted directly behind a ceiling grille. They moved plenty of air and they were genuinely loud, and the louvers leaked conditioned air into the attic all winter because there was nothing insulating them.
Current models are built differently. The motor and blade sit away from the ceiling opening and connect through a short insulated duct, which puts most of the noise at a distance. The ceiling damper is insulated and sealed when closed, so it is not a hole in your ceiling for the eight months you are not using it.
What we look for in a fan
- A remote-mounted motor with a ducted connection, rather than direct ceiling mount
- An insulated, gasketed damper that genuinely seals when closed
- Multiple speeds, so you can run it quietly overnight rather than only at full tilt
- A timer, so it shuts itself off in the small hours instead of running until you wake
- Airflow matched to your house and your attic venting, not simply the biggest available
What it costs
Published alongside our other work
Whole house fan installation in the Fresno area typically falls in the range below, including the fan, installation, the electrical connection, the ceiling damper and commissioning.
- Fan capacity — matched to your square footage and your attic's vent area.
- Ceiling and attic access — joist spacing, framing and how easy the space is to work in.
- Electrical — whether a suitable circuit and switch location already exist.
- Additional attic venting — quoted separately and only where the assessment shows it is needed.
- Multiple units — larger or single-story sprawling homes sometimes work better with two.
Financing is available. If your attic venting turns out to be inadequate and you would rather not address it, we will tell you the fan will underperform rather than fitting it anyway.
Whole house fan questions
How much does whole house fan installation cost in Fresno?
Typically $2,000 to $4,000 including the fan, installation, electrical connection, ceiling damper and commissioning. The variables are fan capacity, ceiling and attic access, whether a suitable circuit already exists, and whether additional attic venting is required. Additional venting is quoted separately and only where the assessment shows it is genuinely needed.
Do whole house fans actually work in Fresno?
Yes, and better here than in most of the country. They rely on cool, dry night air, and the Central Valley delivers a substantial drop from the afternoon peak with low humidity. Once outdoor temperature falls below indoor temperature, the fan flushes the house in minutes and clears the heat the attic stored during the day. They are far less effective in humid climates.
What is the difference between a whole house fan and an attic fan?
A whole house fan mounts in the ceiling of your living space and pulls air from inside the house, out through the attic, with windows open to let outside air in. It cools the house directly. An attic fan mounts in the roof or a gable and only moves attic air, never touching the air you are standing in. It reduces heat load through the ceiling but does not cool a room. They are not substitutes for each other.
Do I really have to open windows?
Yes, every time, and this one matters for safety rather than just performance. A whole house fan moves a very large volume of air and must draw it from somewhere. With windows closed in a home with atmospherically vented gas appliances, it can reverse the draft in a water heater or furnace flue and pull combustion gases, including carbon monoxide, back into the house. Two or three open windows on the far side of the house prevents this entirely.
Can a whole house fan replace my air conditioner?
No, and anyone suggesting otherwise is overselling. A whole house fan moves air, it does not refrigerate it, so it can never cool your house below the outdoor temperature. On a 108-degree Fresno afternoon it does nothing useful. What it does is dramatically reduce how hard your air conditioner works overnight and in the shoulder seasons.
Are they loud?
Much less than the ones people remember. Older fans mounted the blade directly behind the ceiling grille, which put the noise in the room. Current models put the motor away from the opening with a short insulated duct in between, and offer multiple speeds so you can run at a lower setting overnight. It is not silent, but it is a long way from the old ones.
Will it leak heat in the winter?
Not with a properly specified fan. Older units used simple gravity louvers that leaked conditioned air into the attic year-round. Current models use an insulated damper with a gasket that seals when closed, so for the eight months you are not using it, the ceiling stays a ceiling rather than a hole.
Find out if your attic can support one
Free quote including a venting assessment and a check of how your gas appliances are drafting.
Prices shown are typical ranges for the Fresno area and are not quotes. Your firm price follows an on-site assessment including attic vent area and combustion appliance draft. Additional attic venting, where required, is quoted separately. Financing is provided by third-party lenders subject to their approval and terms. California Heating & AC Repair is operated by Craftline Renovations, Inc. · CSLB License #999179 · Licensed and insured.