To put in perspective how much heat is lost, think about a basketball, which is approximately the size of one cubic foot of air. A conventional fireplace exhausts as much as 24,000 cubic feet of air per hour. So, it's essentially like shooting 400 basketballs out your chimney every minute.
On the practical side, however, a traditional open-hearth fireplace loses most heat up the chimney. You're actually fortunate if even 10% of the heat produced by the fire goes into your home.
Studies show that up to 90% of the heat produced by an open fire escapes straight up the chimney. This means that only about 10% of the energy you're putting into burning those logs actually makes it into your living space to warm you up.
Fireplaces are notorious for heat loss. While burning, the average fireplace is operating between 5% and 15% efficiency, drawing almost as much heat up the chimney as it is producing, plus losing a tremendous amount of heat through infiltration and conduction during the 90-95% of time it sits idle in the home.
Install tempered glass doors and a heat-air exchange system that blows warm air back into the room. Check the seals around your fireplace flue damper—if the seals aren't tight, you could be losing home heating through the chimney. Insulate your chimney.
When the fireplace is not in use, your chimney acts like an open window or door. It sucks the warm, ambient air in your home out of the chimney and allows cool air to pour in. A top sealing chimney damper can solve this cold draft problem.
As one of the biggest causes of a draughty home, it can make sense to block a chimney opening, especially for larger unused fireplaces. Fixing a draughty chimney not only makes your home more comfortable, it helps to lower energy costs too.
Wood-burning fireplaces are only able to create a very small amount of heat to begin with, so it's no surprise that they're actually the least efficient type of fireplace when it comes to producing heat. They're also very good at working against themselves by pulling heat right out of your home.
What is The Average Heat Loss in a House? Generally, a well-insulated and sealed home may experience heat loss ranging from 1% to 5% per hour. For example, if the indoor temperature is 20°C (68°F) and the outside temperature is 0°C (32°F), the heat loss would be approximately 0.6°C (1.08°F) per hour.
Understanding Chimneys & Energy Efficiency
Warm air constantly rises, pulling air from your home – up the chimney and out. Cold air then rushes in, replacing the warm air you've carefully heated. This constant exchange can significantly increase your heating expenses.
Installing a wind-directional chimney cap can help prevent downdrafts by redirecting the wind upward, regardless of direction.
The single biggest source of heat loss in the home is an open chimney. It's like leaving a window open all the time, except that the passage of warm air out is exacerbated by a phenomenon known as the stack effect.
According to the Chimney Safety Institute of America, Creosote can ignite at temperatures as low as 451 degrees F (for context, a fire in your fireplace can burn in excess of 450 degrees F), and even just a 1/8” buildup of creosote is considered high enough to cause a chimney fire.
In fact, you can lose 10 to 20 percent of the warm air from your home through your chimney's damper. Suddenly, your fireplace is increasing, rather than decreasing, your home's heating bills!
The standard fireplace is among the most inefficient heating devices you can operate. In fact, it can be so inefficient that in some cases it actually makes your house colder. Inefficiency is not their only drawback.
Yes, it is generally a good idea to remove an old chimney. An unused chimney can cause serious problems, including heat loss, roof leaks, and wasted space in the home.
An estimated 25% of all heat loss occurs through the attic or roof of a home. Cracks or holes in an attic, along with improperly placed vents, allow for significant amounts of heat loss through the attic space. In addition, improper ventilation in attics leads to even more heat escaping.
To determine the annual heat loss, divide the energy loss rate by the design temperature difference and then multiply it by 24 hours per day and the number of annual degree days (from the weather files of the location).
How cold can a house get without heat overnight? The time of day your heater goes out impacts how long the house stays warm. Indoor temperatures go down faster at night, so if your furnace stops overnight, you can expect a quicker decline. This can be as much as 15 degrees Fahrenheit before morning.
Putting a Damper on Your Energy Bills
What's more, between 80 and 90 percent of the heat produced by wood burned in an open fireplace is lost up the chimney. This means that for every $100 you spend on firewood, you get only $10 to $20 worth of heat. The rest goes up the chimney.
Place the box fan on low, facing INTO the space where your fireplace is, blowing the cool air at the unit. This will cause a convection reaction and the hot air will be forced away from the burning unit. If in a small room, the hot air will be moving out the door into larger spaces in no time.
Yet there is nothing quite like a fireplace to not only warm your home but also create a cosy, inviting ambience! The most effective, efficient way to heat your entire home: Wood Burning Stoves or enclosed fireplaces burn wood efficiently, create little ash and debris, and generate plenty of heat.
Chimney Balloons can deflate over time and can be prone to puncturing. Re-inflating them every three months can become tiresome and even messy. Unless you don't mind getting in your hands and knees to re-inflate or re-install your balloon every 12 weeks, we recommend that you get a Chimney Draught Stopper.
Yes, chimneys need to breathe, even if they won't be used anymore. The vast majority of problems with chimneys are related to moisture, and that's the issue as regards ventilation. If there is no air flow in the chimney, moisture gets trapped and deterioration of the chimney structure will be accelerated.
Chimney removal costs
A cowl can be used to cap off the chimney, which will allow air to flow in and prevent any moisture from building up. This costs roughly £150. If you want to remove the chimney breast (the part of the chimney in the room) and have the space made up, this can cost between £1,750 - £3,250.