When should you not use a whole house fan?

The whole house fan should be turned on in the evening hours when temperatures outdoors are cooler, and when the air is dry and cool. Avoid turning on the fan during the day when temperatures are high, or when the air is humid, as it provides you with limited or no benefits in your home.


What are the negatives of a whole house fan?

What are the disadvantages of a whole house fan? While a whole house fan is known for saving money on the cooling bill, it can possibly lead to a higher heating bill in the winter, especially for older whole house fans. An older house fan is a perfect escape for the air you are paying to heat in the wintertime.

Should you run your whole house fan all the time?

We recommend running the whole house fan all night. The goal is to cool your entire house down, not just the air. It takes time to pull the heat out of the sheetrock, structure and contents of a house.


Can you use a whole house fan in the winter?

Using a whole house fan during the winter can actually prove to be largely effective in a myriad of ways. Running your whole house fan also gives you superior circulation of air. During the winter, most homes become stale as people do not open their windows to let new and fresh air in.

When should you use a whole house fan?

A whole-house fan is effective whenever the outside temperature is lower than the indoor temperature, which is usually in the evenings and at night. It typically uses just one-tenth the energy of air conditioning, which means drastically lower energy bills for the typical residence.


How to Size and Select a Whole House Fan for you house



How many windows should be open with a whole house fan?

How many windows should I leave open and which ones? A: Opening two or more windows half way or more is recommended. Basically you should make it easy for the home ventilation system to pull in air.

Can you run a whole house fan with the windows closed?

You should never run a whole house fan without opening windows or doors. This could create a situation of negative pressure and backdrafts. This is when the pressure inside the home is less than outdoors. A backdraft can result in poor air quality, especially with gas-operated appliances.

Do whole house fans use a lot of electricity?

By contrast, a whole house fan has a motor in the 1/4 to 1/2 hp range, uses 120 to 600 watts, and costs around 1¢ to 5¢ per hour of use.


Can whole house fans cause mold?

Since the whole house fan is pressurizing the attic and exhausting that air out of your attic vents, it helps prevent that humidity build up in the attic from your A/C plenum. A whole house fan is one of the best ways to help prevent moisture and mold build up in the home.

Does a whole house fan bring in dust?

Many homeowners also think their house will get dustier by running the whole house fan. However, due to the amount of air a whole house fan moves when properly sized to the home, dust does not have any time to settle in the home!

Is it cheaper to run a whole house fan or AC?

A whole house fan is much more cost-effective to run than a traditional A/C system. While an A/C system runs at 3000 watts or more for smaller homes and much higher for larger homes, a whole house fan runs at under 1000 watts for the largest models and most models at under 500 watts.


Are whole house fans healthy?

Whole house fans are a more natural solution for whole-house ventilation. Whole house fans can provide air changes anywhere between 30-60 times in an hour. This keeps the air in the room fresher and healthier. As they cool the house by bringing in fresh air from outside, they can also be friendly for the environment.

Do whole house fans reduce humidity?

Whole house fans do not affect indoor air quality (unlike other types of cooling systems). Whole house fans lower the temperature inside your home without reducing humidity levels unlike air conditioners, so there is no need to worry about creating the perfect environment for allergens and other irritants.

Why do houses not have attic fans anymore?

One reason that attic fans are inefficient is that they rely on the existing attic vents (at the soffits, ridge, or gables) to make up the air they exhaust. Usually, these attic vents are not designed for this purpose, and they may not be able to supply enough replacement air.


Does a whole house fan work in a two story house?

It won't. Whole house fans are designed to vent warm air from inside the house and to draw outside air into the house. To do this properly doors and windows need to be open, and the fan would suck every last bit of cool air the A/C system produces right outside.

Why do manufactured homes have whole house fans?

Whole house ventilation systems use a series of fans and ducts that run through your home to better control the exchange of indoor air with outdoor air. It operates by pulling air from the outside and circulating it throughout your whole house. It ensures a fresh stream of clean and healthy air round the clock.

Does airing out a room prevent mold?

Another major step to prevent mold growth in your home is to make sure you are properly ventilating your home. Ventilation helps prevent humid air from getting trapped indoors and wreaking havoc with mold growth. Good airflow can help cut back on moisture and will dry wet areas of your home more quickly.


Where should I put my whole house fan?

Typically, whole house fans are placed in the attic between the living space and ceiling. The central hallway is a great place to install your fan in many homes. To install your whole house fan you or your contractor marks your ceiling or wall opening using the premade template.

Do whole house fans need to be cleaned?

Since whole house fans move a lot of air, they should be cleaned regularly. Whenever you are attempting to clean a whole house fan, safety is key.

What is better an attic fan or whole house fan?

To ventilate the attic, the attic fan is a better choice since it actively moves air out of the attic. In fact, the whole house fan only deposits air from the house into the attic. Unless an attic fan has also been installed, the whole house fan relies on passive methods to remove that air from the attic.


Can you run a whole house fan during the day?

Whole house fans can be ran at any time of the day, however, depending on the time of year and the goal you have, the time of day may be different. For cooling purposes during the warmer months of the year, Whole house fans are designed to run whenever it is cooler outside than inside your home.

Does a whole house fan cool the attic?

How Whole House Fans Work. The whole house fan pulls air in from open windows and exhausts it through the attic and roof. It provides good attic ventilation in addition to whole house cooling. Whole house fans should provide houses with 15 to 23 air changes per hour (varies with climate, floor plan, etc.

Do you need a whole house fan if you have central air?

Advantages of a Whole House Fan

Even if you do have central air, using the fan only on days that aren't too hot can save on energy costs. Additionally, running the fan for a while before turning on the air conditioning on the hottest days draws out some of the hot air and make it easier to cool your home faster.


Can attic fans cause mold?

Lack of air sealing

This allows warm, moist air to easily enter the attic. As the moist air impacts the cool roof sheathing, the moisture condenses on the surface. Over time, this leads to mold growth.

What is the ideal indoor humidity level?

The ideal relative humidity for health and comfort is somewhere between 30-50% humidity, according to the Mayo Clinic. This means that the air holds between 30-50% of the maximum amount of moisture it can contain.