Consider These Facts
“When a homeowner is considering installing a fireplace in their home, there are a few things to consider before a final decision is made. For example, a traditional masonry wood-burning fireplace is energy inefficient in producing heat. In general, most heat from a masonry fireplace is drawn up the chimney during the wood burning process. In addition, a wood burning fireplace pulls an enormous amount of warm room air out of the house. The best a homeowner can hope for is to simply equal the amount of heat being produced by the burning wood meaning they are only in the range of minus 10% to plus 10% efficiency,” explains Bill Hussel, owner of Efficiently Yours Fireplace Shop
Inefficient AND Expensive
As if being inefficient wasn’t enough, a masonry wood burning fireplace can be quite expensive to construct. This is due to the substantial footing required and all of the masonry construction in the basement, living area, attic, and through the roof. It can be a tough combination for nearly everyone’s budget.
Trimming Costs and Improving Efficiency
Designed to reduce installation costs and improve efficiencies, Hussel says prefabricated* fireplaces (zero clearance), are being used in new construction more often. Why? Prefabricated fireplaces do not require a large amount of footing and foundation work for support like the heavy masonry units. The result is less cost. Pre-fab units are also slightly more efficient, producing roughly 10 – 20% of heat efficiency.
Gas Inserts: The Most Efficient Fireplaces For Your Home
In order to increase the heat efficiency of masonry or pre-fabricated fireplaces, gas inserts are usually installed and can increase the efficiency from near zero to approximately 75 – 85% percent. The new high tech inserts are very attractive in appearance and look very similar to regular wood burning fireplaces. Most gas inserts draw fresh air from outside of the house for combustion and then exhaust the flue gases after combustion through a secondary chimney.
Gas inserts are efficient because they limit the amount of combustion air being lost from the house during the burning process and also have a very efficient heat exchange system (especially when a re-circulating blower is used) to transfer the heat from the burning fire to the circulating house air. These systems are great from a safety perspective too because they are sealed, so if there is a malfunction, no carbon monoxide will escape into your home.
Wood Burning Inserts: Also 75–85% Efficient
Wood burning inserts are also up to 85% efficient and will produce about 75,000/btu per hour (in many cases enough to heat an entire house). Normally, gas inserts are approximately half the heat production (approximately 35,000/btu per hour).
“Whatever a homeowner chooses, it is important to have the installation and maintenance done properly to be sure your fireplace is safe for your home and family,” says Hussel.
A Clean Fireplace is a Safe Fireplace
Your chimney should be cleaned by a professional chimney sweep, at least once a year, using a rotary brush that will spin within the pipe causing less stress, thereby protecting the pipe. It is best to have the pipe inspected with a video apparatus to ensure its integrity.
Pre-fab fireplaces are generally sheet metal boxes for the firebox as opposed to refractory brick and refractory mortar for masonry units and have air cooled chimneys as oppose to masonry chimneys. The interior surface of the pre-fab chimney is stainless steel and is usually rated by Underwriter Laboratories and other similar testing organizations to withstand a chimney fire. The chimney sections (metal) in zero clearance fireplaces can be pulled apart and allow a gap between the chimney sections which can cause a huge fire risk since the chimney chases are usually constructed of wood. This separation of chimney pipes can occur during construction or during the cleaning process where brushes are pushed through the chimney sections causing the sections to separate in cases where the mechanical lock has been compromised or is ineffective.