Buy the Smartmak: it delivers the same genuine 6kW Harvia heater and plenty of capacity for a household, at a fraction of the Allwood's price. The Allwood 400-EHP is the pick only if you truly need to seat up to eight — otherwise you are paying to heat empty bench. This is an honest apples-to-apples pairing: two electric barrel saunas, both shipping a real Harvia stove, both needing a 240V circuit. The difference is size and money. The Smartmak is the value winner for the vast majority of buyers; the Allwood earns its place only in the specific case where eight seats is a real requirement, not a nice-to-have.
What they share
Start with the common ground, because it is the most important part of the comparison. Both barrels ship a genuine 6kW Harvia heater — the premium stove brand — so on the part that actually makes the heat and the loyly, these two are equals. Both are factory-built kits (Canadian hemlock on the Smartmak, Nordic wood on the Allwood) rather than premium US cedar. And both are electric, which means both need a dedicated 240V circuit, a licensed electrician, and a permit and inspection to code (NFPA). In other words, the heater and the wiring job are effectively a wash. That narrows the real decision to two things: capacity and price. For the wider group-size field, see our best large barrel saunas roundup.
Where the Smartmak wins
The Smartmak's case is simple and strong: you get the same brand-name heater and enough capacity for almost any household, for far less money. It seats four to six — genuinely plenty for a family or a couple who occasionally have friends over — and the bundled 6kW Harvia means easy replacement stones and parts for years. Because it costs a fraction of the Allwood, it frees up budget for the parts of the project that are easy to underfund: the foundation pad, the electrical run, and weathering care. For the overwhelming majority of buyers, that combination — real Harvia, ample seats, much lower price — is exactly the right call. The honest cons are the hemlock body (less aroma and rot resistance than cedar) and factory-kit build quality a step below a US brand. The Smartmak also anchors our best barrel saunas list, and if you are cross-shopping the configurable Benovo instead, our Benovo vs Smartmak comparison settles that one.
Where the Allwood wins
The Allwood 400-EHP has exactly one job the Smartmak cannot do: seat a genuine group. It is built to hold up to eight adults, which is real capacity the smaller barrel simply does not have, and it comes from Allwood, an established kit-cabin brand with a track record in flat-pack builds. If you host large sauna sessions — a big family, a shared setup, a rental — the eight-seat capacity is the whole reason to buy it, and the bundled 6kW Harvia is the same quality stove as the Smartmak's. The honest cons are the flip side of that size: it has a large footprint and a serious install (this is a project, not an afternoon), and it is among the most expensive barrels in this class, with the same 240V circuit requirement. It is the right barrel for a genuine group and the wrong one for a couple.
The capacity trap: heating empty bench
Here is the mistake this comparison exists to prevent. It is tempting to buy the bigger barrel "so we have room," but capacity you do not use is not free — a bigger barrel has more air and wood to bring up to temperature, so you spend more time and energy heating bench nobody is sitting on. If it is usually just one or two of you, the Allwood means you heat a lot of empty room most sessions, and you paid a premium for the privilege. Size to the people who will realistically be in there, not to the largest gathering you can imagine. That single discipline is what makes the Smartmak the right answer for most households and keeps the Allwood honest as a genuine-group buy.
Install: both are a 240V job
Do not let anyone tell you either of these is a plug-in appliance. A 6kW residential sauna heater runs on 240V, which means a dedicated circuit sized to the heater, installed by a licensed electrician, with a permit and inspection to code in almost every jurisdiction (NFPA). That is true of both barrels equally, so it does not separate them — but it is a real cost and a real job you must budget for on either one. Running the circuit out to a barrel in the yard is more involved than an indoor cabin, because the wiring has to reach the sauna safely and to code. Our barrel sauna installation guide covers what the job actually involves so you can brief your electrician properly.
What neither barrel is
Keep one thing in perspective while you compare these two: neither is a premium US-built cedar barrel. Both are factory kits — the Smartmak in Canadian hemlock, the Allwood in Nordic wood — so both trade cedar's aroma and natural rot resistance, and a domestic support network, for a lower price. That is a fair trade and the reason either one is affordable, but it means the real contest here is value-barrel versus value-barrel, decided by capacity and price, not a step up in build quality. If build and a US brand matter more to you than the money, that is a different shopping trip above both of these. And whichever you choose, the wood will want the same care any outdoor sauna does — a level pad, good drainage, and letting it dry between sessions — which we walk through in our best barrel saunas roundup and its planning links.
Who each one is for
Buy the Smartmak if you are a household, a couple, or a family who occasionally has company — you want a real Harvia stove and four-to-six seats without paying big-barrel money, and you would rather put the savings toward the pad and the wiring. Buy the Allwood 400-EHP only if seating up to eight is a genuine, recurring requirement — a large family, a shared or rental setup — and you accept the larger footprint, the bigger install and the higher price that come with it. Both give you the same quality heat; the decision is entirely about how many people you truly need to seat.
The verdict
Buy the Smartmak.For most buyers it is the clear winner: the same genuine 6kW Harvia, ample capacity, and a price a fraction of the Allwood's. Buy the Allwood only if you genuinely need eight seats — outside that specific case, its extra capacity is bench you heat empty and pay for. Both need a proper 240V install from a licensed electrician, so factor that into either budget. If eight is what you need, start with our best large barrel saunas roundup; if it is not, the Smartmak is your barrel.
How to choose between them
Count the seats you actually need
This decides it. If four to six seats covers how you will really use the sauna, the Smartmak wins on price with no downside. Only the specific need to seat up to eight — a big family, a shared or rental setup — justifies the Allwood's size and cost. Buy for your normal session, not your biggest imaginable gathering.
The heater is a tie, so ignore it
Both ship a genuine 6kW Harvia, so the stove — usually the most important spec on an electric barrel — does not separate these two. That is a good thing: it means you are not trading heater quality for price on the Smartmak. Let capacity and cost decide, because the heat will be the same either way.
Do not pay to heat empty bench
A bigger barrel has more air and wood to warm, so an oversized sauna costs more to run every session, not just to buy. If it is usually one or two of you, the Allwood's eight seats work against you twice — higher purchase price and more energy heating space nobody uses. Right-size and save on both.
Budget the 240V install for either
Both barrels need a dedicated 240V circuit, a licensed electrician, and a permit and inspection in most areas (NFPA). That cost is roughly the same on both, so it does not favor either — but it is real, and it is easy to forget when comparing sticker prices. Add it to both columns before you decide.
Weigh the footprint and the pad
The Allwood's larger body needs a bigger, level foundation and more clearance in the yard than the Smartmak. If your space is tight, that alone can settle it. Confirm the footprint fits your pad — and that you can run power to it — before you commit to the bigger barrel.
Remember what both leave out
Neither barrel is premium US cedar — both are factory kits, so you are choosing between two value barrels, not between value and premium. That keeps the decision clean: because build quality and heater are effectively level, let the number of seats you truly need, and the price, make the call. If domestic build and support matter more than the saving, that is a reason to shop above both of these rather than to pick the bigger one here.
