Why do I have air vents in my house?

Asked By: Nermine Parron | Last Updated: 24th March, 2020
Category: home and garden indoor environmental quality
3.9/5 (345 Views . 16 Votes)
Moisture can condense, leading to problems with damp, while inadequate air flow results in a build-up of indoor air pollutants from household products. It can also produce cold, uncomfortable indoor temperatures, while good ventilation can help to maintain a comfortable inside temperature and a fresh and healthy home.

Click to see full answer


Likewise, people ask, is it necessary to have air vents in walls?

No worries, But yes you must have some form of ventilation, either trickle vents in the windows, acoustic trickle vents in the walls or a heat recovery system. Unfortunately moisture in the air is common of everyday living and it needs to go somewhere and we need changes of air too.

Likewise, should you open all the vents in your house? The answer, unfortunately, is no. You are better off keeping the vents open to ensure the unit operates efficiently. This way over the lifetime of your system you can save on energy use and repair costs.

Consequently, why do you need air vents in houses?

A house needs to be well ventilated for the comfort of its residents and to help care for the building. Moisture can condense, leading to problems with damp, while inadequate air flow results in a build-up of indoor air pollutants from household products.

How many air vents does a house have?

Having several return vents (ideally one in every room, but even two or three is better than just one) creates consistent air pressure. If you have one return vent, your home is fine.

33 Related Question Answers Found

What happens if no ventilation?

Well, poor ventilation can have serious consequences. It can make our homes “sick”, with condensation and mould damaging the walls and fabric of our houses. But, more importantly, it can make the occupants sick. Mould, mildew and mites all thrive in environments that are high in humidity.

What are the vents in my walls for?

Moisture Control
In some older homes, wall air vents helped remove moisture build-up between exterior and interior walls. Removing excessive interior moisture mechanically though metal ducts and static vents required taking the moist air and circulating it through a dehumidifying system.

Can I cover an air vent?

You could mess with the air flow.
Just because you cover the vent, it doesn't mean your HVAC system knows that. It will keep pushing air to those vents, and if they're closed, you could cause a buildup of air pressure and insufficient airflow which could damage your system.

Where should vents be placed in a room?

Supply register vents should be in every room as well. Located on the outer walls, under windows, in the ceiling, or on the floor, placement depends on the heating or cooling system as well as the construction of the home. Supply vents help change the room temperature to your desired heat or cool setting.

Why do old houses have air bricks?


Airbricks, sometimes called air bricks or air vents, are special bricks containing holes that allow air to enter under the floor of buildings that have suspended floors. Cavity walls also need ventilation to allow airflow that will prevent moisture build up.

How do you seal air vents?

To properly seal around air vents, apply caulk or expanding foam between the ducting and the sheetrock. The goal is to prevent conditioned air from escaping or unconditioned air from entering the thermal envelope. Next, apply weather stripping around the underside of the vent cover.

What happens if you block an air vent?

If you start to block the vents, static pressure will build up in the supply air path or duct. The vents which are kept open starts to serve more air. This may cool down the serving area more which is not acceptable. Also, the static built will cause a back pressure to the blower and affect its performance .

Why do we need ventilation system?

A ventilation system is needed in order to obtain oxygen for living organisms and to get rid of carbon dioxide. Surface diffusion utilized by many smaller organisms is not sufficient in supplying the oxygen needs of the body. It is also needed to maintain a concentration gradient in the alveoli.

How can I block vents in my house?

  1. Step 1 – Close Vent Grilles. Most vent grille covers have a lever on the side which adjusts the angle of an array of metal fins.
  2. Step 2 – Seal Perimeter of Vent Grilles. Turn off the heating system temporarily and inspect around the vent grille cover for air leaks.
  3. Step 3 – Block Vent Grilles.
  4. Step 4 – Insulate Duct Work.

How do I open the vents in my house?


How to Open & Close Ceiling Air Vents
  1. Place a stool or ladder under the vent you want to adjust.
  2. Step up on the ladder or stool until you can comfortably reach the vent.
  3. Locate the dial or switch on the vent.
  4. Turn the dial on the square or round vent to the right to open the vent.

Does closing vents downstairs help cool upstairs?

Opening upstairs cold air supply registers fully and all but closing downstairs air supply registers helps direct the cold air upstairs. You are literally rerouting the circulation of the air pushed out through your air conditioner. Be careful not to fully close all downstairs air supply registers.

How do I reduce airflow in my vents?

High static pressure makes airflow more audible
  1. Adjust the fan speed. Your blower or furnace fan should be set to deliver the proper airflow per ton.
  2. Add ductwork.
  3. Add a bypass duct.
  4. Add or expand grilles and registers.
  5. Replace existing registers and grilles with high velocity models.

Does closing vents redirect air?

Homeowners typically close vents in an attempt to redirect air away from unused spaces. The belief is that closing a vent will simply push the air onward to other parts of the home, improving energy efficiency.

Should you close doors in unused rooms?

Should You Close Doors in Unused Rooms. In short, the answer to this question is no. Although closing off unused rooms may seem like a way to save energy on heating and cooling, it can actually force your HVAC system to work harder.

Why is one room colder than the rest?


If some rooms are warmer or colder than others, this is usually just a matter of balancing. Meaning adjusting the airflow to each room so they all even out. If a room is heating or cooling much quicker than other rooms, the airflow can be reduced to that room to even things out, also sending more air to other areas.

Is it bad to close vents in your house?

Because closing vents will cause pressure to build up in your ducts, your air conditioning unit or heater will have to work much harder to distribute the air properly. So not only is closing a vent counterproductive in terms of lowering energy usage, it will also create larger and more expensive HVAC repairs over time.

Should I close vents in winter?

If you have a top/bottom return vent setup, close the top vents in the winter months. Closing the top vents will make your system draw in air from the bottom vents that are at the low point in the room where cold air settles.