Comparing A JUCA Model L-8 Fireplace Insert
To Competing Air-Tight Inserts

As you research your choices of products available, you will find that virtually ALL of the competing products are so-called AIR-TIGHT devices. Some are called CATs and some are non-CATs, depending on whether they have a catalytic combustor. ALL of the competing products have rather small fireboxes. That makes it so that they can ONLY take small, thinly split, pieces of wood, which then requires those products to use suffocation techniques in order to make the fire last longer. Their approach does accomplish this, but at a cost. The airtight product's NECESSARY limiting of oxygen to the fire, of not letting it have enough oxygen to burn properly, creates terribly incomplete combustion.

This limits efficiency, of course, but it also causes production of large amounts of pollution and also large amounts of creosote which could condense and accumulate in the chimney.

In order to combat these problems, airtight products use either a catalytic combustor or they attempt to introduce secondary combustion air above the fire. The overall design idea of airtights is that they can later solve the problems THEY CREATED in the main fire by limiting the available oxygen. Sometimes they do, and sometimes they are unsuccessful, depending on very complicated interactions of temperature, fuel, oxygen, turbulence, and smokepaths. So, when airtight products brag about having a catalytic combustor or of having secondary combystion air, uit is kind of a left-handed claim! They actually only NEED such things because of their original design that first suffocates the fire to control it. And, unfortunately, those methods of curing their own problems ONLY work SOME of the time, when a variety of conditions permit it.

In the 1980s, airtight fireplace inserts developed a very BAD reputation for generating lots of creosote in chimneys and fireplaces, especially when accumulated huge creosote deposits in the firebox behind some inserts later caught fire and caused house fires. The Government and insurance companies interceded. By the late '80s, ALL AIRTIGHT INSERTS were required to be provided with a DIRECT-CONNECT kit, a hose-type smoke outlet which had to channel all the smoke up past the fireplace throat damper and directly into the chimney. This requirement was instituted EXCLUSIVELY to eliminate creosote accumulations behind the air-tight inserts.

Text Font Face
Text Size
(for printing)

If you think about it, you're probably aware of a fireplace in the family which was used for 50 years without ever accumulating massive creosote. A thin coating of soot in the chimney was all that had ever accumulated. Why was that?

That old fireplace was always allowed to have adequate oxygen for complete combustion! Virtually everything which could be burned, WAS burned! Virtually no pollution. Virtually no creosote.

Unfortunately, also virtually no HEAT!

Enter the JUCA Fireplace Insert

Our JUCA product works by a technology that involves NON-airtight operation. The fire is allowed to have adequate oxygen for extremely complete combustion, so there's high combustion efficiency and almost no creosote or pollution (as long as you use reasonably seasoned wood for fuel. Of course, if you burn plastic or utility poles or tires (which we do NOT recommend), all bets are off on what goes up your chimney)

Since this product is non-air-tight, it is exempt from the requirement of the direct-connect kit, and rightfully so since it doesn't accumulate creosote in the firebox when used properly. It is also exempt from the EPA restrictions on pollution particulate matter (grams per hour) which all air-tights must conform to.

Since the direct-connect kit is not used, installation and removal are remarkably easy (except for the fact that the unit weighs about 350 or 400 pounds!).

OK, so the JUCA Fireplace Insert is friendly to the environment and to your chimney. You're not interested in buying one just to be a nice guy! So how does it work?

Since the JUCA Fireplace Insert allows the fire to burn relatively normally, is was necessary for the JUCA designers to surround the fire with high efficiency, computer-designed heat exchangers to capture the heat and send it out into the house. The sophisticated heat exchangers are unlike anything in the industry. Very efficient. AND, they are each individually custom-designed and built for a specific fireplace!

Where most competitors use a minimal fan (usually 60 or 100 cfm), the JUCA L-8 uses a 465 cfm blower to accentuate the efficiency of the heat exchangers and additionally to more aggressively spread the heat around your house. (The L-10 uses a 336 blower). Where competitors sent their small amount of very hot air slowly out vents which are usually at the top of their units (and heat rises, so it immediately aims for the ceiling), the JUCA sends the warm (not hot) air nearer floor level to warm your feet and distribute the heat more evenly around the room and even into adjoining rooms.

Comfort levels are MUCH improved!

We've taken care of clean burning, environmental friendliness, high combustion efficiency, and high heat transfer efficiency, and all that is left is burn time. Since that was the original reason air-tight products came into existence (to extend burn times), let's discuss how a JUCA accomplishes this goal.

JUCA custom builds each and every Fireplace Insert specifically for that one particular fireplace! This allows you a very large firebox, in which to put quite a lot of wood. More importantly, you can use THICK pieces of wood. It turns out that the thicker a log is, the longer it will burn. Think about camping out overnight. In the morning, which pieces are still hot and glowing or sometimes even still burning? The thickest ones! 8" diameter logs in a JUCA will burn about 10-11 hours! The fact that they have relatively little flame seems like a disadvantage, but it actually turns out to be a plus.

By burning leisurely, the fire burns amazingly completely. Combustion efficiency is at its highest. The highly efficient JUCA heat exchangers then extract the bulk of this heat energy for the house. The heat production is very long, very constant, while still being very clean-burning.

An ideal solution! There are some air-tight products which have come on the market which don't use a catalytic combustor (non-CATs). Most have VERY small fireboxes which then usually need their draft controls to be left wide open in normal operation, effectively acting as a NON-airtight much of the time! They are almost trying to be like Mike! (Oops! Sorry! JUCA!)

The JUCA Home Page is at: juca