Wouldn’t it be great if you could have the warmth and light of a fireplace without the mess, hard work, and inefficiency? Would it surprise you to know that there are options for people who live in homes without existing fireboxes and chimneys?
Check this out.
Gas or propane powered fireplace inserts are safer, easier to install, give the same beautiful, flickering firelight, and heat your home more efficiently than old, wood-burning types. They come in so many styles to fit every home décor scheme from classic and traditional wood mantelpieces to sleek, modern styles with black metal and crystal.
The latest ceramic logs look just like the real thing, too. Most are hand-painted and manufactured to glow and spark like natural wood.
We have done the research for you and found the 10 best gas fireplace insert options for a cozy, warm, and attractive home. All you have to do is make the final choice, have it properly installed, and start enjoying the new ambiance and affordable heat throughout the year.
The ventless Mountain Vernon gas fireplace insert offers a realistic look, plenty of efficient warmth, and flexibility of fuel and size that can help homeowners choose the right option for any room in the house
You can use any type of gas or propane fireplace, an outdoor fire pit, or other unit and get heat and light. For a realistic look and the cozy ambiance you want, you need realistic logs over the flames. These fit the bill
Can you really have an attractive mantel, realistic logs, and flames, plenty of heat, all for an hour’s worth of installation time? We find that the ProCom vent-free “Apple Spice” model gives you all that and more
Do not skimp on traditional style just because you go for a non-traditional gas-powered fireplace instead of wood. The rich heritage style of this surround and mantel will give any room a touch of classic elegance. Excellent, safe heat, too!
A truly unique gas fireplace, the Plazmafire model combines modern looks with easy installation, flexible fuel choices, and a wealth of efficient heat for your home. The installation process was described as easy as hanging a picture on the wall
One of the larger fireplace inserts at 35 inches wide, this Ruby Series black surround unit offers unique styling and high output, very safe and efficient heat. The Monessen system includes everything you need to set up and start enjoying the dancing flames and warmth right away
Ideal for inserting into an existing fireplace box, this Sure Heat ceramic log set looks quite realistic with its variety of sizes and shapes for the six attached logs and tiered grate. They are molded from actual wood and hand painted in various brown and tan shades.
The log insert will fit in any fire box at least 15 inches deep, 25 inches wide at the back, and 36 inches wide at the front. There is also a smaller option available.
Get a cozy glow with either liquid propane or natural gas fuel and easy ignition with just the push of one button. This Emberside by SureHeat Vernon Oak gas log set will heat up to 1500 square feet if properly installed.
Flexible options of fuel sources make it usable by most people and homes.
This unit is highly efficient when it comes to heating a room. People who bought it reported heating an entire 1700 square foot house with it, providing all the heat for a country cabin, and enjoying the warmth anytime they want.
The gas fireplace insert weighs under 50 pounds, which makes it easy to move and install for most handy people.
Heating a full 1500 square feet will cost you just 25% of the same heat output with a traditional wood fire.
SureHeat offers a one year warranty for manufacturer's defects. They offer replacement parts or refund if necessary. This does not cover user error or misuse.
Many customers who chose this model of gas fireplace reported very easy installation and quick, sure heat without any time wasted.
This fireplace insert consists of only the log structure and fuel hookups. You need to have or build a fire box to sit it inside.
Due to the layout of the logs and tiered rack, this cannot be used in a two-sided or see-through fireplace.
The Mount Vernon model has no thermostat for automatic on and off. It must be operated manually with a switch.
Multiple customers complained that the unit arrived broken or with missing pieces. There is a 30-day return policy in place.
No matter what type of insert you get to warm your home, it will not look its best without realistic looking logs inside. Instead of normal wood that is messy and has to be replaced all the time, these ceramic logs will last virtually forever.
The Natural Glo wood-style logs work in any brand or model of gas fireplace. You can use them indoors for a cozy scene or outside for late night relaxation and socializing.
This set of large ceramic logs includes 10 pieces from 10 to 15 inches long. We love the fact that you can arrange them however you want. Maybe you prefer a neat and orderly stack, a campfire-style teepee, or a casual jumble.
The brown bark, pale wood inside, and rough charred surfaces combined with flickering orange flames make your fireplace or fire pit look just like the real thing.
We love the very realistic appearance of these gas fireplace logs. Many others are solid brown and do not have char marks like real wood gets in a fire.
Their versatility makes this product popular with people who have indoor vented gas fireplaces using either natural gas or propane, electric fireplaces, and outdoor gas-fueled fire pits as well.
The logs themselves retain heat and can keep heating the room or outdoor area even after the fire is turned off.
The 100% guarantee lets you return the ceramic fireplace logs if anything at all is wrong with them or if you simply change your mind after purchase.
The set of 10 ceramic logs do not come with a stacking diagram or instructions. You will have to figure out the best configuration yourself.
They are 10 to 15 inches long and all of them may not fit in a smaller unit.
In some cases, using these in another fireplace may void its warranty.
Some customers reported a bad initial smell when burning these for the first time.
The realistic look and feel of a gas-fueled fireplace make any room cozy and comfortable, but if the model you get does not have an attractive surround, then it ruins the whole ambiance of the room.
The “Auburn Cherry” finish on the furniture-style mantel of Duluth Forge’s fireplace looks as good as or better than any built-in model you may find. Display knick-knacks, hang holiday stockings or put up a portrait of your favorite person for a completely classic and elegant look.
This vent-free fireplace does so much more than look good, however. With 32,000 BTUs of power, it can heat an entire small home, or about 1200 square feet, with ease. It can use either propane or natural gas.
We love the included remote control for turning the flames on or off and adjusting the thermostatically controlled temperature.
We love the gorgeous wood-grain finish on the mantel and surround. It looks perfect in a traditionally decorated room.
Heats up to 1500 square feet of living space without the separate blower. If you add on that extra module, you can get even more power out of the 32,000 BTUs.
Realistic ceramic logs come with numbered pegs and slots so you can fit them together perfectly the first time. This gives you a natural-looking fire without headaches or damage from falling logs.
Don't worry! Buyers report overwhelmingly that this fireplace is very easy to set up and get working. You can enjoy the flickering flames and wonderful heat in no time.
Residents of California cannot purchase the Duluth Forge gas fireplace because of local regulations about vent-free models. Unfortunately, this covers all fireplaces of this type.
Some buyers were not happy that the flames were a single height only and could not be adjusted up and down. The temperature can be changed, however.
The blower unit that pulls in air from the room and then pushes heated air out again is a separate purchase and not included in the stated price.
For homes with existing fireplaces or for people who prefer to build a structure around and insert, and this neat black metal gas fireplace works perfectly. The face of this vent-free unit from Duluth Forge is matte black with clean, flexible styling that can suit any preferences. The natural-looking logs within and the dancing flames will make it the favorite spot to enjoy staying at home.
Looks are not the only thing that is important, however. How would you like 99.9% efficiency with 26,000 BTUs of heat-producing power?
It operates on either natural gas or propane and can be turned on or off easily with the included remote control. Mantel is a perfect bonus item!
The no-clearance construction means it fits neatly inside most fireplaces to make it highly efficient and attractive.
The remote control not only turns the unit on and off but it can adjust temperature and flame height to completely customize the user experience.
People who bought this fireplace insert reported that it was very easy to install and they had it up and running in a short amount of time.
The inside appearance of the firebox was described again and again as very realistic and natural looking. The rear and side walls have a brick pattern and the faux logs have cut, bark, and char sections.
This is only a plain insert and will need an existing fireplace and mantel or you will have to build one in your home. That adds somewhat to the expense and difficulty before you can enjoy the unit.
Vent-free units are not allowed in California and will not operate well at high altitudes.
Some customers who had defects or missing parts with the shipment reported very poor customer service.
There is just something about a classic fireplace with a wooden mantel that instantly boosts the elegance and style of any room. ProCom Dual Fuel Vent-Free Fireplace offers just that.
The warm wood surround has a classic style. The black metal insert, realistic ceramic logs, and flickering orange and yellow flames will leave people amazed that it is fueled by something other than real wood.
This 26,000 BTU unit will heat up to 1000 square feet with ease. Based on efficiency calculations, this level of BTU output has even been known to heat up entire homes under 1500 square feet. An optional blower unit may help. This no-vent model is a highly recommended gas fireplace insert propane or natural gas fueled.
Includes everything you need to install an attractive and efficient fireplace in any room of your house: living room, bedroom, den, or even an enclosed porch for all-season use.
No vent necessary for clean and safe use. This product includes an air-quality sensor to make sure everything stays healthy for you, your family, and pets.
The flexibility of either natural gas or propane fuel makes the ProCom 26,000 BTU fireplace insert very attractive for many homeowners all over the country.
Cannot be purchased in California or Canada because it does not have an external vent.
The blower unit is optional and is not included in the price. This sucks air in from the room and blows heated air back out again, perhaps increasing heat output.
Uses approximately 3.5 gallons of propane for every hour of operation, which some consider not cost effective.
Have you dreamed of a cozy hearth to sit near while you read a book, watch TV, or play a game with your family?
Did you always want the cozy flicker of natural flames and more efficient heating options in your home? This beautiful ProCom fireplace can give you all of that without the need to rip open your wall and construct a traditional fireplace and chimney.
The wood-grain mantel offers a rich walnut finish. The ceramic logs inside are hand-painted for maximum realism. The flames are fueled by your choice of natural gas or propane and deliver comfortable heat to 1000 square feet or more. You can have everything you had ever wanted in a fireplace without the mess and expense of wood burning.
Pure style comes in every inch of this gas fireplace. It looks as good as any built-in fireplace with a mantel perfect for displaying treasures or installing a flat panel TV above.
Brick-look insides and hand-painted logs continue the realistic appearance. No one will guess you are not burning genuine wood.
You have complete control over the temperature output and height of the flames. We find this lets you create the exact look and feel you want in your home.
Customers rated this ProCom unit very highly for its heat output and appearance. Overall, we found no sufficient complaints at all about this ProCom fireplace model.
No remote control is included with this fireplace, which knocks a bit off the convenience factor of gas-fueled flames. You need to manually turn it on and off and adjust the thermostat to your desired temperature.
The entire structure weighs over 130 pounds. The heavy weight makes it difficult for one person to do the installation alone.
Since it operates without a vent, it cannot be sold in Canada or California. These locations, and possibly several more municipalities or cities around the United States, do not allow ventless fire operation.
For homes with an existing fireplace and mantel, or for those who want to build their own to match the wood trim and crown molding or whatever other styles they love, this vent-free gas fireplace insert suits well. The Napoleon 30,000 BTU unit puts out amazing heat with just a flip of the switch.
Need just some gentle warmth instead?
You can adjust flames and heat to 50% level easily.
Besides style and heat, the Napoleon vent-free fireplace offers helpful safety features too. A traditionally-styled safety screen keeps pets and kids away from the flames. A high-tech oxygen depletion sensor turns off the unit automatically if air quality in the room is compromised.
It offers a very authentic appearance that reminds us of the old wood-burning fireplace at home. The black surround and optional louvers showcase the quality logs and flames well.
Natural gas and liquid propane models are both available. Since no conversion kids exist, simply order the correct one for your preferred fuel type.
Safety features abound on this Grandville VF Series gas fireplace. The included safety screen keeps hands away from the flames and the oxygen depletion sensor shuts the unit down automatically if air quality decreases too much.
One buyer states that it heats an entire 1200 square foot condo with cathedral ceilings perfectly without the need for additional utility expenditures. This definitely falls in line with the power of 30,000 BTUs, a number slightly higher than similar models that only offer 26,000 BTUs.
The louvered edges shown on the product picture are a separate, add-on piece that pushes the price higher. The blower unit is additional, too. These recommended items add efficiency and to the overall appearance.
No remote control is offered on this model, making it slightly less convenient to turn on and off.
According to the manufacturer, this fireplace will not operate properly at elevations over 5,000 feet. While this is inconvenient for those that live in the high country, it is a standard problem that all ventless units share.
While most gas fireplaces either need to be inserted into an existing fireplace or are positioned flat against the wall, this Pleasant Hearth convertible model lets you position it as a corner unit as well.
The attractive wooden board cabinet has the option to fit in multiple ways to suit whatever style of shape your room is in. No vent needed.
Flexible options for natural gas and liquid propane fuel. Optional Pleasant Hearth blower unit for increased efficiency. All of these factors work together to make this stylish fireplace a great choice.
The "Rich Heritage" faux paneling and stain color suit many traditional or country homes. The mantelpiece is very impressive and looks just like the real thing.
What could be better than total control over how much heat the fireplace makes for you? We think the two burner system and the included thermostat make staying comfortable simple.
From the electric ignition to the overheating safety kill switch, this unit has a wealth of safe home features to protect your property and loved ones.
Buyers shared their experience with installing the convertible fireplace and report that it was quite easy to put together and get into position with one or two fit people. They appreciated that this unit could sit against any wall or fill a corner perfectly.
This is a very heavy unit, coming in at 140 pounds. This may make it difficult for one person to install it on their own. Many people opt for professional installation help due to fuel hookups anyway.
The Pleasant Hearth fireplace does not come with a remote control for either on/off or temperature control. This reduces the convenience slightly when relaxing across the room and enjoying the warmth.
The position of the controls, which are underneath the fireplace in the front, can be difficult to operate for some people, especially when the fire is lit and producing heat.
Forget stained wood surrounds and jumbled piles of authentic-looking logs. If you have a more modern or minimalistic style home, you need a gas fireplace that matches your personal tastes without compromising efficient heat or safety.
This Napoleon fireplace has a neat black surround and CRYSTALINE™ embers instead of faux wood to burn. The high-tech style matches all the latest and best heat-producing qualities of inserts. No vent is needed for Plazmafire operation.
Homeowners can choose between propane or natural gas fuel, which makes this model very convenient in all areas and property types. Internal filter tiles and an oxygen sensor keeps things safe for you and your family.
We found this Napoleon wall-mount fireplace to have one of the cleanest modern appearances out of other models on our list. The wide black surround sets it off nicely from the wall directly or any trim options you choose.
The unique slate brick panel in the back and sides of this model give a realistic appearance without the look of traditional brick. Perfect for a modern home!
Electronic ignition switch means fast fire whenever you want it and easy off when you have enough heat in the room. This also improves the safety factor if something goes wrong and you need to shut off the unit immediately.
For improved air quality, the Plazmafire model comes complete with catalytic filtering tiles and an oxygen depletion sensor. We love having no need to worry about air quality while enjoying the warmth.
Since this fireplace is designed to hang on the wall, some homeowners might find it difficult to install. It weighs 92 pounds and would need a strong support to maintain safety and prevent damage.
Ventless gas fireplace inserts are not allowed to be purchased or used in Canada and California. Other local ordinances may prevent their use as well.
The top of the unit gets quite hot and may make installing a wall-mounted television, artwork, or any furniture pieces above it difficult or dangerous.
Some features like the LED lighting and safety screen are optional and carry extra expense above the normal purchase price. These are, however, not vital to operation and are more for appearances and added safety.
Enjoy efficient heat and classic style with this black fireplace insert by Monessen. More than just a simple box with fuel hook up for natural gas, this fireplace adds a touch of stylish interest with the unique edges, the realistic brick-look side, and rear walls, glass front, and authentic ceramic logs.
This model requires a vent for proper use and to maintain appropriate air quality inside the home. The easy ignition system and included remote control make it simple to operate. The 35,000 BTUs of power make it awesome at heating a large area of your home with ease.
Appearance is not everything, but we think it matters quite a bit when putting a fireplace in your living room, bedroom, or enclosed porch. This insert has classic black color with a touch of detail in the barred design.
A full 35,000 BTUs of heating power mean high temperatures and a farther reach than smaller models. We find that these levels can heat a small house, condo, or apartment with ease.
Detailed ceramic fiber logs look like they are burning realistically behind a safety glass front. The logs mimic the appearance of genuine wood.
The total package includes the gas connector, two-speed blower, and convenient remote control. These are often separate purchases on other models of gas fireplace insert.
Requires external venting hardware that is not included with the fireplace purchase. This means an extra expense for both the parts and the installation procedures.
This large unit weighs 180 pounds, which makes it virtually impossible for one person to move it into position and install it alone.
The black surround fireplace only uses natural gas as fuel for the flames. There is no conversion available for propane. This makes it less flexible than other models for people who usually use LP gas to heat or power their home.
How We Tested
You and your family are sitting in the cozy living room enjoying the warmth and light from what you thought was the best gas fireplace insert when the flames surge out of control, fumes fill your room, or another horrible situation occurs.
Sounds scary, right?
Luckily, you do not have to worry about such things happening because every quality gas fireplace is rigorously tested by the manufacturers and independent sources before they are put on the market. They test gas connections and vents to ensure safety for you and your family.
All materials that go into the construction of these units also go through testing to make sure they do not burn, melt, or emit toxic or noxious fumes when subjected to heat.
The experts also measure BTU output closely to make sure the product descriptions are accurate. Proper BTU rankings mean you know exactly how much space in your home can be heated with each unit. Individual states and the Environmental Protection Agency (EPA) have regulations in place to ensure safety for every household that uses one.
How to Choose Best Gas Fireplace Insert
Deciding which fireplace to choose is a tough decision with so many great options on the market. Due to the fact that most are similarly safe and functional, we think the final choice comes down to the size you need to heat the space in your house and what the fireplace looks like.
Simply select the type you want, either an insert alone or a full fireplace with mantelpiece. Then, choose the preferred fuel type or the one you have access to in your location. This could be natural gas or LP liquid propane. Check local rules about vent requirements, too. Some locations do not allow vent-free fireplaces. It’s common for California, for example.
Other options include a gas fireplace insert double-sided, gas fireplace insert with blower, and gas fireplace insert with glass. We have also discovered quite a few ideal gas fireplace inserts for outdoors. Mantles come in metal, faux stone, and wood grain designs.
Advantages Of a Gas Fireplace Insert
Many people love having a fireplace, but they cannot make up their mind whether they should choose wood, electric, or gas. All three have their benefits and disadvantages, which makes the choice confusing.
Every single thing we love about having a fire inside is better, more efficient, and usually safer with gas.
First, they are safer than wood fires. You will never have any exploding wood knots of flying sparks. Second, they are much more efficient than both other options. Gas fireplace inserts with a direct vent offer approximately 75% efficiency, while a vent-free model is nearly 99% efficient. This means all the fuel gets used to make heat that you and your family can enjoy.
Perhaps the best advantage yet?
Who wants to chop and haul wood around, sweep up chips and sawdust, and deal with hot ashes?
Not only is dealing with all that wood back-breaking and messy, it can also cost more than other fuel types.
With the cleanest burning gas or propane fuel, the room will never get that unpleasant smoky smell. You will have no soot residue on your walls, furniture, and ceilings either.
New fireplace means ripping out a wall, building a hearth, box, and chimney with brick or stone, and disrupting everyone’s life for days or even weeks, right?
This sounds like a lot of fuss and bother for something that might look nice, but ends up being an inefficient heat producer.
Believe it or not, you can avoid all that hassle when you choose a gas fireplace instead. The only difficulty may occur if you choose a vented model and do not have an existing chimney or vent available.
Vent-free models are as easy as pushing or carrying it into place, hooking up the gas line or propane canister, plugging it in, and firing it up. You could start heating your home, saving on utility bills, and enjoying the look of real flames in hours rather than days.
We recommend having this done by an experienced professional.
Any time gas is involved, things could get dangerous until everything is attached and sealed properly. Of course, this involves some extra expenditure of money, but the peace of mind of knowing no gas or LP is coming into your home may be well worth it.
All Types of Gas Fireplace Inserts
The different types of gas fireplace insert are as varied as the houses to put them in. First, they vary based on the fuel type. Some use propane, others natural gas and still others can use either. Conversion kits come standard with some models and are add-ons for others. Your choice!
Next, there are both vented and vent-free models. They are both safe, efficient, but we suggest the ventless ones since they are much easier to install. Look for ones with air quality sensors for greater peace of mind.
Finally, gas fireplaces come in a vast array of styles. We reviewed a collection with the style of antique gas fireplace inert options with classic wood mantles, gas fireplace inserts that have modern styles with minimalistic metal surrounds, and others that can be inserted into any existing fireplace.
Care and Maintenance
The fireplace is installed, you have enjoyed the light and warmth of it, but now it is time to do some maintenance and you have no idea how to tackle the job.
To put it simply, every gas fireplace insert will come with instructions from the manufacturer. If you follow those, you should be fine. One vital care task is to call in an official inspector or trained technician to go over all the parts and check for damage, deterioration, or dangerous leaks.
In between those annual visits, care for the gas fireplace by keeping everything clean, clearing dust and debris from the vents, repairing or replacing damaged glass, wood, or other surround material, and the ceramic logs.
Wouldn’t it be great if you could enjoy a crackling fire at home without worrying about sparks escaping and setting something on fire?
Traditional wood fireplaces not only risk the room they are in but can also cause severe structural damage. According to the Chimney Safety Institute of America, some chimney fires go undetected.
How scary is that?
Don’t worry. There is a solution besides avoiding fireplaces altogether. Gas fireplace inserts burn clean, may not even need a vent or chimney, and never build up dangerous creosote that can burst suddenly into flames. Many models also come with air quality sensors built in to ensure healthy breathing for everyone in the home.
We believe that warranties are great for any type of product, and so we are happy to see that many of these models offer them.
In most cases, a warranty would not cover user error or damage caused by accidents like getting hit with something. They cover manufacturer defects, although those should be noticed when the gas fireplace insert is being installed. Some could occur after use as well.
Different companies that make these heating inserts offer different warranties. Always make sure you read them carefully before making your final decision about which to buy.
Because these are usually quite heavy and expensive to ship, refund policies are also something that you have to check out. Getting a damaged unit and having to pay to ship it back could cost more than having it fixed locally.
If you have an existing fireplace that you want to upgrade to gas, one of the realistic log inserts is a great option. Someone with experience must run a gas line and seal off the usual chimney and opening into the house when you put the insert in. This makes for extra efficiency overall.
Do not worry if you do not have a fireplace. The wonderful thing about gas fireplaces is that they do not have to be inserted into anything to work well. Standalone models have a fire box, all necessary hardware, attractive surrounding frame or even a full mantelpiece. All they need is access to natural gas or propane and an electric outlet nearby.
The good news is that a gas fireplace can go anywhere in the house you want extra light, style, and heat. Put one in the living room for a classic look and comfortable evenings around the fire. It is just like the old family home minus the inefficient heating, the heavy wood to carry, and the frustration of not lighting the fire the first, second, or even third time.
How about a fireplace in the bedroom? What could be cozier or more romantic than flickering flames? What could be more comfortable than the warm glow on a chilly winter morning? Cozy reading nook? Man cave or den for toasty warmth during the big game? The only limits are your personal tastes.
Compared to traditional wood-burning fireplaces, gas inserts are miles ahead when it comes to safety.
Don’t believe us? Take a look at the following comparisons.
Wood can split, pop, and even explode in a fireplace due to the composition of the wood and moisture content. This can send flaming wood chips out onto the rug or into the face of someone stoking the fire. A gas fireplace completely negates that possibility. No sparks, no potential pieces flying out ever.
Burning wood can create creosote buildup in the chimney. This natural tar-like substance can block air flow or burst into flames. It is possible to have a fire in the chimney itself and never know about it until disaster strikes. Gas options burn clean and leave no residue or noxious fumes behind. Many even have air safety sensors to make sure you have fresh air to breathe.
What about the dangers of gas itself?
It is true that natural gas or propane can cause fires and explosions if there is a leak or an improper seal. In a properly working insert, all the gas burns off cleanly and never escapes into the house. A semi-annual inspection gives you peace of mind that this extreme circumstance will never happen.
This answer might surprise you. Many people seem to think that burning gas or propane all the time to heat a room or the whole house would take a big bite out of their budget. We found that it’s really the other way around.
The basic formula for figuring out how much running the unit will cost is the number of BTUs times the cost of gas or propane per therm and dividing by 100,000. You can find the latter number by looking at your gas bill or contacting the local utility company.
We were happy to see such low costs per hour. For example, if gas costs 90 cents, running your 32,000 BTU fireplace for an hour will be only 29 cents per hour for wonderful heat! Even one of the most expensive rates, around $1.50 per therm, only results in a 48 cent per hour charge.
Just think of all the other expenses you save at the same time. No more buying cords of wood every winter. No more electric bills out of control with space heaters. No more hitting the shops for new sweaters, slippers, and throw blankets just to stay comfortable in your own home.
The simple truth is that one fireplace insert will probably not be sufficient to heat your entire home if it has multiple floors or a high square footage. People who have purchased them regularly say that they heat an entire apartment or home under 1500 square feet with a single unit.
Of course, a solution to the need for more heat is to have more than one installed in various rooms throughout your living space.
How much will a single unit heat?
This depends on the type if it has a vent or not, and the BTUs it puts out.
First, determine what type you need: just gas-powered logs to sit in an old wood-burning fireplace that uses the existing chimney, a full insert for an existing fireplace with a direct vent, or a vent-free standalone unit.
The logs and gas hookup alone will not be much more efficient than the wood-burning fireplace. These are mostly for ambiance. A full insert with direct vent leaves about 70% of the generated heat inside the house. A unit without a vent leaves 99% of heat inside because there is simply nowhere else for it to go.
But that is not all you have to take into consideration if you want to heat your home. BTUs are the other criteria. The amount you need is determined by a simple formula. Simply multiply the square footage of the room, times the ceiling height, times the BTU zone your house is in. These range from #1 in the southern USA to #5 in the north.
The answer to this question depends largely on how much skill and experience you have doing advanced projects around the house. If a vent needs to be installed through the wall, it becomes a larger construction project. If you need to run a natural gas or propane line and make all connections secure, calling in a professional is recommended.
There are many websites and videos online with directions about how to install a gas insert and the one you buy may come with instructions as well. However, only you know your skill level and how comfortable you are making changes to your home.