High Efficiency Wood Stoves: Which Numbers Are Real
Updated September 2026
Two wood stoves are sitting side by side. One is advertised at 80% efficient, the other at 74%. The 74% stove is very likely the more efficient of the two.
That is not a trick. It is what happens when manufacturers quote two genuinely different measurements under the same word. One is a best-case figure taken at the stove's sweet spot. The other is an average across a full certification test, calculated on a stricter basis. They can differ by six to eight points on the very same appliance — and we can show you that on stoves we sell, using the manufacturer's own published numbers for them.
This guide explains which number to look at, why the gap exists, and lists the efficiency figures Drolet and Englander publish for every freestanding wood stove we carry.
The two numbers, and why they disagree
Optimum efficiency is the best result the stove produced at its most favourable burn rate during testing. It is a real measurement, but it is a single point on a curve — the equivalent of quoting a car's highway mileage and calling it fuel economy.
Average efficiency (HHV) is the figure averaged across the full range of burn rates in the EPA certification test, calculated on a higher heating value basis. HHV counts the energy lost to boiling off moisture in the wood, so it is always the lower and stricter of the two. This is the number that appears on EPA certification paperwork.
You will also see LHV quoted, which excludes that moisture loss and therefore reads several points higher than HHV for the same stove. Optimum figures are stated on an LHV basis — the Drolet and Englander manuals say so outright — which is part of why they always look better.
Here is the gap on one appliance. The Drolet Escape 1800 publishes all three:
| Figure quoted for the Escape 1800 | Value | What it means |
|---|---|---|
| Optimum overall efficiency | 79% | Best single burn rate |
| Average efficiency, LHV | 77% | Averaged, moisture loss excluded |
| Average efficiency, HHV | 72% | Averaged, moisture loss included — the strict figure |
Seven points of spread, one stove, all three numbers accurate. A retailer wanting to make the Escape 1800 look good quotes 79%. A retailer being conservative quotes 72%. Neither is lying, and you have no way to tell which convention you are reading unless the page says so.
The same pattern shows on the Drolet HT-3000: 77% optimum against 71% HHV average, six points. And on the Drolet Spark II N: 81% optimum against 74% HHV average, seven points.
Every published figure, side by side
These are the efficiency numbers Drolet and Englander publish for the freestanding wood stoves we sell, with the measurement basis shown so you can compare like with like. Every figure is copied from the performance table in the stove's own owner's manual, which you can download from each product page and check for yourself.
| Stove | Optimum | HHV average | Heats up to | Price |
|---|---|---|---|---|
| Drolet Spark II N | 81% | 74% | 1,200 sq ft | $1,049 |
| Drolet Escape 1200 N | 81% | 74% | 1,200 sq ft | $1,129 |
| Englander Blue Ridge 100 | 80% | 74% | 1,200 sq ft | $1,049 |
| Drolet Fox | 80% | 74% | 1,200 sq ft | $999 |
| Drolet Spark II | 80% | 74% | 1,200 sq ft | $999 |
| Drolet Deco Nano | 80% | 74% | 1,200 sq ft | $1,079 |
| Drolet Escape 1800 | 79% | 72% | 2,100 sq ft | $1,549 |
| Drolet Heritage | 79% | 72% | 2,100 sq ft | $1,589 |
| Drolet Deco Alto | 79% | 72% | 2,100 sq ft | $1,699 |
| Englander Blue Ridge 300L | 79% | 72% | 2,100 sq ft | $1,419 |
| Englander Blue Ridge 300P | 79% | 72% | 2,100 sq ft | $1,449 |
| Drolet HT-3000 | 77% | 71% | 2,700 sq ft | $1,899 |
| Drolet Escape 2100 | 77% | 71% | 2,700 sq ft | $1,929 |
| Englander Blue Ridge 500 | 77% | 71% | 2,700 sq ft | $1,749 |
| Drolet Columbia II | 76% | 68% | 1,800 sq ft | $1,279 |
| Drolet Blackcomb II | 76% | 68% | 1,800 sq ft | $1,279 |
| Drolet Deco II | 76% | 68% | 1,800 sq ft | $1,349 |
| Drolet Escape 1500 | 76% | 68% | 1,800 sq ft | $1,349 |
Start with the first three rows. All three heat 1,200 sq ft, and the Blue Ridge 100 and Spark II N are both $1,049. Quote the Englander at its 80% optimum and the Drolet at its 74% HHV average — which is exactly how two different spec sheets can end up presenting them — and the Englander looks six points better. Put both on the same basis and they are within a point: 80% against 81% optimum, and an identical 74% HHV average. The gap was never in the stoves, only in which column got quoted.
Now look at how the numbers cluster. Drolet and Englander are both built by SBI, and within a size class the figures repeat regardless of the badge: every 2,100 sq ft stove reads 79% and 72%, every 2,700 sq ft stove 77% and 71%, and every compact except the two newer N models reads 80% and 74%. The bottom four rows — the 1,800 sq ft class — carry the widest spread in the table: 76% optimum against 68% HHV, eight points on the same appliance.
That is the whole lesson. Never compare an optimum number against an HHV number. If the basis is not stated, the figure tells you nothing useful about how one stove compares with another.
Efficiency is a smaller lever than you think
Every stove on this page is EPA 2020 certified, and the spread between the best and worst of them is a handful of percentage points. Three things in your control move the needle further than the number on the spec sheet.
Wood moisture. Burning wood at 30% moisture instead of 20% wastes a large share of the fire's energy boiling water out of the log before it can heat anything. No stove design recovers that. This is the single biggest variable in real-world efficiency, and it costs nothing but planning ahead.
Sizing. An oversized stove gets damped down to avoid cooking you out of the room, and a damped-down stove burns dirty and inefficiently — well below any number in the table above. An undersized stove runs flat out and wears quickly. Our stove sizing tool matches firebox and BTU output to your square footage.
The flue. A stove is only as good as its draft. An oversized, cold or unlined masonry chimney will undermine the best stove made. If you are venting into existing masonry, price a stainless liner as part of the project rather than an afterthought.
Put differently: a 74% stove burning seasoned wood in a correctly sized installation will beat an 80% stove burning wet wood in an oversized flue, every winter, by a wide margin.
What high efficiency actually buys you
A higher-efficiency stove sends less of the fire's energy up the chimney. In practice that shows up as fewer cords burned per season, longer burns from the same load, and less creosote to sweep out, because more of the smoke is being consumed in the firebox rather than condensing in the pipe.
What it does not buy you is a different heating capacity. Efficiency and output are separate specifications. The Spark II N sits at the top of the efficiency table and heats 1,200 sq ft; the Escape 2100 sits several points lower and heats 2,700. If your house needs 2,700 sq ft of heat, the efficiency column is not the one to sort by.
High efficiency wood stove FAQs
What is the most efficient wood stove you sell?
Among our freestanding wood stoves, the Drolet Spark II N and Escape 1200 N lead on optimum at 81%, a point ahead of the 80% shared by the Englander Blue Ridge 100, Drolet Fox, Spark II and Deco Nano. On HHV average — the stricter, more comparable basis — all six compact stoves tie at 74%. The honest answer is that the top of our range sits within a point of itself.
Is 70% efficiency good for a wood stove?
On an HHV average basis, yes — that is a modern EPA 2020 stove performing normally. The same appliance would be quoted around 76–77% on an optimum basis. An open masonry fireplace, by contrast, is often a net loss of heat from the house.
Why do two retailers list different efficiency for the same stove?
Almost always because one is quoting optimum and the other HHV average, without saying which. Both can be sourced from the manufacturer. Check the basis before you conclude one page is wrong.
Do catalytic stoves run more efficiently?
They generally post higher figures and hold long low burns better, at the cost of a combustor that needs periodic inspection and replacement. Every stove we sell is non-catalytic. Our guide to catalytic vs non-catalytic stoves covers the trade in full.
Does a blower make a wood stove more efficient?
It does not change combustion efficiency, which is what these numbers measure. It does move heat off the stove and into the room faster, which usually makes the installation feel more effective. See do you need a blower on a wood stove.
Do you charge sales tax on wood stoves?
No. StoveSource charges no sales tax in any state, and orders over $250 ship free to the lower 48 with curbside freight delivery.
Related guides
- Best Wood Stoves of 2026: Top Picks by Home Size & Budget
- What EPA Certification Means on a Wood Stove
- The Most Efficient Pellet Stoves: How to Read the Numbers Before You Buy
- Catalytic vs Non-Catalytic Wood Stoves
- Best Drolet Wood Stoves 2026: All 13 Models Ranked by Home Size
Browse all wood stoves — No Sales Tax in any state, free shipping on orders over $250. Want help matching a stove to your square footage? Call 1-888-914-0022.
Efficiency figures are the manufacturer's own published values from each appliance's owner's manual as of September 2026, reproduced with the measurement basis they were published under. Prices are current at time of writing and exclude any promotional discount.