The air conditioner relies on vents to pump conditioned air into the room and remove stale air for conditioning.
However, these vents end up in inconvenient places at times.
At other times, you just don’t have enough room to avoid obstructing them with furniture.
So, Is It OK to Put Furniture in Front of a Wall Vent?
If you’re thinking large couches or sofa-like furniture, it’s a straight NO. Furniture with large spaces beneath them like tables is largely harmless. Small and lightweight furniture is less likely to obstruct your vents to a point of a major malfunction. How close is “in front” is a factor to consider as well.
For any HVAC system to function flawlessly, the accompanying vents need a clearance of at least 10 inches off the nearest sizeable object. Placing large furniture too close to vents (less than 10” in) is bad for both the furniture and your HVAC system.
What Are The Two Types Of Vents?
As you already know, your air conditioner uses two types of vents to service the room –
- and return vents.
Supply vents deliver conditioned air into the room while return vents draw the stale and warm air from the room into the ductwork to be transferred into the machine for conditioning.
Here is why you shouldn’t put large furniture in front of supply vents:
1. Conditioned Air Has a Drying Effect That Can Damage Wooden Furniture
Conditioned air carries very little or no humidity, meaning it has a drying effect on almost everything it comes into contact with.
If you ever left your AC machine running overnight and woke up with drier skin and eyes, that was it.
Placing your wood furniture very close to air vents will damage the wood.
The same drying effect the conditioned air has on your skin will certainly take a toll on the wood now that the furniture’s surface is very close to its exit point.
Wood glue and joints are especially vulnerable and are normally the first to loosen and crack before you notice discoloration on the furniture directly in front of the vent.
2. Blocked Supply Vents Overwork Your HVAC System
Obstructed supply vents give your AC system a hard time pumping conditioned air into the room.
As such, it must work harder to deliver your conditioned air.
The main problem with an overworked machine is that it has to run a little often and sometimes longer than usual. That does worse than hastening the wear and tear.
You will take some time to realize that blocked return vents are the culprits behind your bloated energy bills.
In most cases, the damage is minor enough to keep the machine working smoothly.
In some, complete replacement of the inefficient machine can be the only option left.
Another relatively common sign of an overworked air conditioner is strange noises that get louder with time.
If you live in an area with strict noise rules, you will need to repair or replace your machine.
Obstructed return vents are just as bad as supply vents if not worse.
With furniture in the way, the machine will have a hard time drawing the bad air from the room, causing it to work harder than usual.
For that reason, obstructed return vents are bad for efficiency very much like their supply counterparts in the same state.
There are more reasons why you shouldn’t inhibit airflow into return vents:
1. Pressure Build-Up
The air conditioner must keep a pressure gradient to your service the room as required.
An obstructed return vent will certainly build up the pressure in the room.
High room pressure in turn causes the machine to work harder trying to supply conditioned air into the room, rendering it inefficient even further.
2. Air Stagnation
Ever noticed that stagnant water tends to be dirty but flowing water is almost always clean?
The same applies to room air. An obstructed return vent means very little or no stale air is leaving the room (unless you open windows and doors, of course, but what’s the point in having an AC system?).
Stagnant air tends to be humid and dirty and bad for your health.
There are two other highly undesirable effects of this kind of air – rot, and mold!
Tricks Around Furniture and Similar Obstacles
Let’s say the vents were installed in inconvenient places or you just don’t have enough room to arrange the furniture the right way. In either or both of those situations, here is how to keep your vents running uninhibited.
1. Get Yourself an Air Deflector
Air deflectors are designed to release (when placed on supply vents) or collect air (when placed on return vents) sideways rather than straight into or out of the space directly in front of them.
Most of these devices, like the example above, can be adjusted to lean at a degree or stand straight at 90 degrees in which case it would mean the front space is obstacle-free.
This way, they help you avoid two problems:
- Firstly, the cold/hot air won’t blast straight in your face.
- Secondly, they let you remove the need for a clearance area directly in front of the vent meaning you can place anything very close to the vents without worry.
2. Go for Custom-Built Furniture
Another trick around the airflow obstruction problem is to acquire custom-built furniture (those designed with vents in mind).
This type of furniture comes with a void beneath them or mesh-like parts either at the bottom or in the headrest area allowing unrestricted airflow into or out of the vents.
3. Increase The Operating Speed
This isn’t even a trick. I’d recommend it with my tongue in the cheek because it’s the farthest I could go to condition an overcrowded room with unavoidable obstacles in front of my vents.
If you didn’t know, the speed of the fan on your AC machine is adjustable but only when necessary.
In any humid season, say, the winter, you wouldn’t run your AC machine in the same setting as the summer.
You are free to reduce the speed of the fan in humid conditions to boost the comfort levels in your home.
If the vents aren’t functioning as required as a result of obstruction (which is unavoidable in this case) but you still need your conditioned air, the only option at hand would be to reduce or increase the fan speed depending on:
- which of the two types of vents is obstructed and,
- the level of humidity in your room.
I don’t recommend it but if it can work for you as a temporary solution as you figure out how to decongest the room, go ahead and make adjustments.
To summarize everything, it’s never a great idea to obstruct your vents with anything including furniture.
However, if you must obstruct them – say, the room is congested and you have no choice – buy and install air deflectors to change the way the air enters or leaves the vents.
Purpose-built furniture can be a great solution as well.