Mitch Heller sees the same trend every fall: When the temperature starts to go down, his fireplace business heats up.

"People are not very proactive; they're reactive," said Heller, owner of the Custom Fireside Shops in Sacramento and Elk Grove. "They wait until they're cold before they come on in."

It's always warm and cozy in his store. A fixture on Auburn Boulevard for more than 40 years, the store has about 100 gas inserts on display; 40 are burning brightly at any one time.

"People want to see them on," he said. "Dress in layers when you shop; it gets hot in here."

This is the time of year homeowners go in search of (hot) deals on heat – from natural gas to wood to pellets and electricity.

The best sellers: gas inserts.

"There are so many more options now," Heller said of gas. "They're not only more efficient, but they look better. They're pretty darn realistic."

Bob Mandelson, who recently bought a home in Sacramento's Greenhaven/Pocket neighborhood, is among consumers shopping for a gas insert.

"The house has this giant hole," he said of the fireplace. "I was just going to burn firewood. But my next-door neighbor said 'Don't!' There could be soot buildup, I could start a flue fire and it could burn the house down."

In addition to lessening fire danger, Mandelson also was attracted to the idea of saving energy and money to heat his home.

"With an efficient fireplace insert, I could probably heat the whole house, or at least the rooms I use," he added.

So Mandelson decided to start doing some homework. "I learned what to consider: BTUs, noise, flexibility, visual appeal, efficiency, warranty and ignition – whether it's self-igniting or not," he said. "There's a lot to consider."

Rebate, tax credit and incentive programs also spark interest in inserts. For example, Mandelson's insert could qualify for up to $750 in incentives.

Another reason for the rise in popularity: Consumers can save money by zone heating, warming an area in use instead of heating the whole house.

"Most families spend a majority of their time in one or two rooms in their home, so using a fireplace or wood stove to heat only those rooms can cut back heating costs significantly," said Jess Baldwin, vice president of Vermont Castings. "If a home isn't already equipped with one of these products, they can typically be put in at a reasonable cost. Installing a fireplace or wood stove is actually much more affordable than homeowners think."

Some models cost less than $3,000 plus installation, Baldwin added. With proper venting, these modern gas-burning fireplaces can be placed in nontraditional places, such as second-floor bedrooms or in the center of a home, away from outer walls.

Fireplaces now are treated as appliances, said Bob Dishner, marketing director for Lennox Hearth Products.

"Years ago, a fireplace would be built by a mason, brick by brick," Dishner said. "Now, it's a manufactured appliance, similar to a furnace. It's treated and labeled like any major appliance, too, with energy standards and ratings. And it installs easily and quickly."

The low cost of natural gas has helped spur interest in inserts and all-gas fireplaces.

"Right now, natural gas is still relatively inexpensive and it's expected to stay that way," Heller said.

An efficient gas insert costs 30 to 50 cents an hour to operate and produces enough heat to warm up to 1,500 square feet.

"That allows home owners to keep the whole-house furnace off and save money," Dishner said. "The No. 1 search on our website is consumers looking for gas inserts. It's a way people can turn an existing fireplace into something they use and enjoy more often."

In a typical conversion, two ducts are run up the chimney: One to bring air in, the other for exhaust. The conversion can cost less to install than repairing a defective chimney.

"The insert does not fit your fireplace exactly; there's always a gap," Dishner explained. "But now there are so many different styles. You can find one for any decor."

An option for all-electric homes: an electric fireplace.

Makers of several models, Twin-Star Classic Flame electric fireplaces use LED lights to mimic burning logs and embers. The unit stays cool to the touch, but warms the room like an electric space heater.

The Twin-Star models don't need installation – just a standard 120-volt outlet to plug in.

"Electric fireplaces are primarily to look at," Heller said. "Most are 1,500 watts, but only heat 200 to 300 square feet."

Stoves that burn wood pellets also are gaining in popularity.

"Our sales are up 20 percent over last year," Heller said of such stoves. "They're particularly popular in the foothills for people (whose homes) are on propane instead of natural gas."

New ultra-low-emission designs allow stove owners to use them more often.

"Last winter, we had 23 no-burn days for people with open fireplaces," Heller said. "For these EPA-approved stoves, there were only three no-burn days. They're so much cleaner."

That's an important difference, especially if the stove or fireplace is used to warm the house.

Said Dishner, "You've got to ask yourself: Do you want a fireplace to look at or for heat? Most people want the heat."

Regardless of what's powering those flames, there's something magical about a glowing fireplace on a cold winter night.

"A fireplace brings family together," Dishner said. "People like to sit around the fire and relax. It adds a lot more to a room than warmth."

© Copyright The Sacramento Bee. All rights reserved.

Call The Bee's Debbie Arrington, (916) 321-1075.

• Read more articles by Debbie Arrington