When Should I Open and Close My HVAC Dampers? In most houses, dampers on the upper level are opened in the summer and shut in the winter. In the winter, closing the dampers on your HVAC system to the upstairs allows for heat to rise naturally as it is distributed throughout the home.
If the damper is left open during summer, you will notice a damp, musty smell from your fireplace. What is that smell? Its mold and mildew collecting from the humidity pouring into your home; shutting the damper will keep damp air, dew, and rain from coming down your chimney and causing it to smell moldy.
You want to start by making slight adjustments in each room. If a room is too hot, you will want to crank open the damper just a bit to add more airflow to the room. If a room is too cool during the summer, you will want to slightly close the vent so that it stops some of the air from entering that room.
By not creating an airtight seal, these dampers minimize the strain on the system. In summer, you can close the dampers downstairs so cooler air reaches upstairs rooms. But in winter, closing upstairs vents halfway allows heat to rise.
Hot air rises and cool air sinks. Therefore, opening the right return vents in the summer and winter significantly improves the distribution of air by your forced-air system. You'll also enjoy more even heating and cooling throughout your home. In the summer, open your high returns and close the low ones.
Conclusion. In summary, keeping your air vents open is generally the best practice for maintaining an efficient and comfortable home environment. Closed vents can lead to increased energy consumption, uneven temperatures, and potential damage to your HVAC system.
Regardless of the choice, specific conditions must be met to comply with these codes. However, we firmly advocate for closing the vents year-round, as it is challenging to regulate summer humidity levels in an open crawl space, leading to potential moisture-related issues.
In the summer, the lower level is naturally cooler, and most people report having hot rooms. In the summer, it's critical to open the dampers on the upper level and block as much air from entering the basement as possible.
One common myth about chimneys is that leaving the damper open during the summer helps “air out” the chimney. However, the opposite of true. Leaving the damper open just fouls up the rest of your home, and does nothing to clean your chimney.
Excessive static pressure inside an HVAC system is never a good thing. Closing too many air supply dampers could put you in the static pressure “danger zone.”
The damper to your fireplace must be completely open when a fire is burning. If you close the damper even slightly, you risk allowing smoke and other dangerous contaminants from the combustion process into the house. And remember, the most dangerous by-product of combustion is carbon monoxide.
Poor insulation can worsen temperature differences between floors. Heat from the sun can penetrate through the roof and walls, making the upstairs warmer. If your attic or walls are not adequately insulated, it can result in significant heat transfer.
Additionally, due to its increased surface area, flex duct may impede airflow somewhat when compared with more streamlined rigid ducts. In some cases, an insulated flexible line may also be necessary if sound dampening or temperature stabilization are desired properties of a ventilation system.
The handle to open and close the damper should be above the fireplace opening. To open it, slide it to the right. To create fires that produce more heat, open the damper as wide as possible when lighting a fire. A wide-open damper will increase the amount of air reaching the fire and improve combustion.
Closing your fireplace keeps your space cool.
If you keep your damper open, your air conditioner will have to work much harder to keep your space at a comfortable temperature. This can result in higher energy bills, and warm, humid air from outside can still make its way into your space.
Use the Damper to Control Heat
Depending on how far open or shut you have the damper, your fire will be smaller and cooler (and burn for longer), or larger and hotter (and burn more quickly). The damper is usually located at the bottom of the stove.
Warm air from your home naturally rises, and an open chimney provides an easy escape route. In fact, it's estimated that up to 30% of your home's heated air can be lost through an open chimney when the fire isn't in use.
You need to open the damper when you start a fire to allow for proper airflow and let the smoke out. A closed damper can restrict airflow and become a safety issue since smoke would fill your house.
(Hint: In the summer months, open the top vents and close the bottom ones to draw out air from a higher point in the room where it's hotter).
Outside and exhaust dampers will generally revert to a normally-closed (NC) position, while return air dampers will revert to their normally-open (NO) position to ensure that any supply fans are not deprived of fresh air.
Add dampers to the ducts. This directs the airflow coming from the HVAC unit and shifts the desired amount to each room. Some ducts are already equipped with dampers and can simply be adjusted. Modify the settings of the air cleaner/filtration unit.
Closing the vents doesn't do it any favors. In fact, instead of helping the air conditioner cool less, closed registers force the same amount of air through other ducts. This builds pressure in the system and makes your HVAC system work harder to distribute the air where you need it.
Sealing locks out moisture-laden air from the outside while insulation ensures the crawl space air doesn't escape to the outside. The result is a clean, dry, and temperature-controlled space.
It's important to remember that static vents serve a purpose, especially in older homes. They provide ventilation to indoor spaces, help regulate indoor temperatures and prevent the build-up of excess moisture in wall cavities and rooms which can lead to mould outbreaks and damage to building materials.