Share
Greetings - we have 8 ceiling air-con vents in our home (one in each of the 4 bedrooms, plus loungeroom, dining/kitchen, hallway, and front entrance hall). I'm unsure whether I should close the vents (they are 4-way vents like in the below picture) to help keep the house warmer, or keep them open (I read that doing so can actually make your HVAC system work harder and potentially cause damage - we have a gas heater). Does anyone have any advice? Many thanks.
Hello @AussiePossum
Since you have a gas ducted heating system with ceiling vents, the best approach is generally not to close too many vents at once, and to be strategic about which ones you adjust. Those 4-way ceiling vents are designed to distribute warm air evenly across a room, and while it might seem logical to close vents in unused rooms to redirect heat where it’s needed, closing too many vents—especially without consulting the system's capacity and design can cause backpressure in the ductwork. This can reduce efficiency, make the system work harder, and in some cases even lead to premature wear or damage.
If your system was designed with balanced airflow in mind (as most modern systems are), it’s better to keep most vents at least partially open. However, partially closing a couple of vents in rooms you don’t use often (like a spare bedroom) can help concentrate warmth where you need it just don’t close more than about 20–25% of your vents without professional advice. You can adjust the direction of airflow using the louvers on your 4-way vents rather than shutting them completely, which helps fine-tune comfort without overloading the system.
If you have any other questions we can help with, please let us know.
Eric
Hi Eric, many thanks for your reply. To add to my first message - the 4-way ceiling vents are only for our air-con (brand: Seeley International) system. They don't release warm air, we get that only from our 'Regency FG39 Medium Freestanding Gas Log Fire' heater in the loungeroom (picture included). As this natural gas heater isn't directly connected to the ceiling vents for air-con, would this make a difference as to whether they should or shouldn't be closed in winter? (I should have included this info previously, my apologies!)
Hello @AussiePossum
Since the heater is not connected to the ceiling vents, closing them off would technically not be an issue. My only concern in closing off the vents is condensation being trapped inside the ducting. If part of the vent is open it should still allow a bit of airflow to pass through allowing any trapped condensation to evaporate. If it was totally closed the condensation could possibly settle at the bottom of the ducting causing mould and mildew to grow in the ducting. My best advice is to leave one section to allow airflow to pass through.
If you need further assistance, please let us know.
Eric
