If your home feels chilly even when the heat is running, there may be a sneaky culprit at work – one that’s hiding inside your walls.
We’re not talking drafty doors or leaky windows.
We’re talking about convective loops in wall cavities, which are a lesser-known but major source of convective heat loss in a home.
Let’s walk through what a convective loop is, how it forms, and most importantly, how to reduce heat loss in a home caused by this invisible air movement.
• Convection heat loss happens when air moves inside wall cavities and carries heat with it.
• There are two types of convective loops: open convective loops and closed convective loops.
• This air movement leads to cold rooms, high utility bills, and even frozen or burst pipes.
• Convective loops happen in poorly insulated or uninsulated walls, including block walls and metal framing.
• Air sealing the building envelope is the most effective way to stop convective heat loss and improve comfort.
A convective loop is a circular air movement pattern inside your wall cavity.
Warm air rises, cool air sinks, and that creates a cycle – kind of like a tiny invisible Ferris wheel of temperature swings inside your wall.
That airflow carries heat away, creating convective heat loss, which can make rooms colder and HVAC systems work harder.
Convective heat loss occurs when air circulates through walls, pulling heat with it and lowering indoor comfort. And because it happens inside the wall, most homeowners never realize why their home feels drafty.
There are two types of convective loop heat loss: open and closed convective loops.
Let’s get into the difference between the two.
This one has a direct connection to the outdoors.
Result? Heat is literally escaping your house.
This type stays inside the wall cavity, but it’s just as problematic.
Even though the air never leaves, the constant warm-cold cycle steals heat from your home, causing uneven temperatures.
Convective loops most commonly occur when wall cavities lack insulation or air sealing, including:
If air can travel freely inside the wall, convective heat loss can and will happen.
Let’s break down the consequences of convective loop heat loss.
Traditional insulation materials degrade faster when air continuously moves through them.
Over time, they simply stop performing.
Circulating cold air in wall cavities can freeze plumbing, and nobody wants a surprise indoor waterfall.
Warm air from ducts loses heat to the cold air looping inside the walls.
Your furnace works harder, and your energy bills climb.
Convective loops can trick your thermostat into thinking the house is colder than it is, leading to 20 to 50 percent higher heating costs.
Those “why is this room always freezing?” complaints?
Yup, that’s convective looping.
You can’t see inside your walls, but you can diagnose the problem.
A blower door test can identify air leaks by measuring the pressure throughout the home.
A thermal imaging camera will show cold spots inside wall surfaces where convective loops are active. If you see cold streaks vertically or horizontally across the wall, that is a convective loop in action.
If you believe your home has been affected by convective heat loss, you have a few options to fix it.
When the building envelope is sealed, cold air can’t sneak in and warm air can’t escape, meaning consistent comfort and lower bills.
Convective looping may be invisible, but the effects are hard to miss – cold rooms, frustrated thermostats, and rising energy bills.
Air sealing your walls makes your home:
If you’re ready to fix convective loop heat loss for good, find a RetroFoam dealer near you and take control of your comfort.
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Convective loops form when air can move inside uninsulated or poorly insulated wall cavities, creating continuous circulation.
Very – especially in older homes, block construction, and buildings without fully continuous insulation.
Air sealing the building envelope and adding foam insulation is the most effective long-term solution.
Not effectively.
These materials struggle to stop air movement, which is why foam performs better in this situation.
Uncomfortable rooms, cold walls, high bills, or thermal imaging scans are strong indicators.