Harvia Family Hybrid Small: Indoor Sauna
Two kinds of heat in one cabin, on a 16 amp circuit rather than a 35 amp one.
£6,396.00
Free standard delivery on orders placed by 30 September 2026
Delivery from £250 on orders placed after that
Exact cost confirmed for your postcode before dispatch.
Typically 8 to 10 weeks, depending on availability and the season. Email us for a current date, or we confirm yours when you order.
- Delta 3.6kW heater, PRO-D2I control and Finnish stones included
- 350W VitaMy infrared radiator and RGBW lighting included
- About 15.7A at 230V, so a 16A circuit rather than a 35A one
- Cabin
- Solid spruce element cabin, 40mm walls, lime wood interior
- Inside
- A 1.54m bench and a 0.74m bench, with a backrest and a headrest
- Heater
- Harvia Delta D36E, 3.6kW, with the PRO-D2I control unit and Finnish stones
- Infrared
- One VitaMy 350W radiator on its own control output, used with or without the heater
- Lighting
- An RGBW strip built into the roof support, plus a 40W white set
- Electrics
- About 15.7A at 230V, so a 16A circuit, wired and certified by an electrician
- Building it
- Two people, a 2.3m ceiling to assemble in, and 5cm clear of the wall
A hybrid is not a compromise between two things, it is two things in one room: Finnish heat when you want to sweat, and an infrared panel on its own when you want twenty warm minutes and no steam.
Delivery & installation
Delivery is available across the UK and the charge is confirmed for your postcode in writing before anything is dispatched. Offshore and some remote postcodes cost more, and we tell you the figure before you commit rather than after.
The cabin arrives flat, as wall, roof and glass elements with the benches, heater and electronics boxed separately. The number of packages and their weights are being confirmed with the distributor and are not published here until they are, because on an indoor cabin the question that actually matters is whether the largest element turns your stairs, and a guess is no use to anybody.
Installation can be arranged where you would rather not build it yourself. Once you place your order we confirm the delivery and installation options for your location, and nothing is dispatched until you are happy with both.
Warranty
Two years on the cabin against manufacturing defects, and two years on the Delta heater, the PRO-D2I control and the infrared radiator, under Harvia's published warranty terms. Registering the heater with Harvia adds a third year on it, and it is worth doing on the day the electrician signs off rather than remembering it in year three.
Harvia name the exclusions plainly, and they are the parts that wear: heating elements, timers, relays, light bulbs and sauna stones. Anything caused by not following the installation, use or maintenance instructions is excluded too, which on an indoor cabin usually means the ventilation or the electrical connection rather than the cabin itself.
The warranty runs from the date of purchase. Harvia's own terms allow a claim to be made to the seller, so claims come to us. One email, and we deal with the distributor and Harvia on your behalf rather than handing you a phone number.
Returns
Until the order is placed with the supplier you can cancel and be refunded in full, with no reason needed.
After that the cabin is on its way from the factory, and our returns policy sets out exactly where that leaves you. Harvia ask that missing parts are reported within 14 days of delivery, so check the packages against the parts list in the manual on the day; anything that arrives damaged or faulty is ours to put right either way.
Who this is actually for.
Every product here is described with the honest opposite beside it: who it suits, and who should be looking at something else.
At 3.6kW this draws about 15.7 amps, so it wants a 16 amp circuit. That is an afternoon for an electrician rather than a conversation with the network operator, and it is the single biggest practical difference between this cabin and almost every other sauna on this site.
Worth confirmingyou want the heat of a 9kW room. A 3.6kW heater in 4.6 cubic metres gets there, but a bigger cabin on a bigger circuit gets there harder and holds it better with the door opening and closing.
The 350W radiator runs on its own output, so a twenty minute infrared session costs a few pence and needs no warm up. That is the part people use on a Tuesday. The Finnish side is for Saturday.
Worth confirmingyou only ever wanted a traditional sauna. The infrared adds cost and one more control to learn, and the plain Family cabin in the same size does the traditional half on its own.
The product that gets used is the one worth recommending, and it is not always the largest one.
The measurements that decide it.
Read this before anything else. An indoor cabin is almost never sent back because it was the wrong product; it is sent back because it would not go up the stairs or stand up in the room.
The ceiling is the one to respect. Harvia's own instructions ask for at least 230cm of room height to carry out the assembly, which is more than the finished cabin needs, because the elements have to be tipped upright.
From order to first use.
Here is each stage, and who does what. Before you order, email hello@tarnfell.com and we will confirm the current lead time and the delivery cost for your postcode in writing.
- Week 0
Order and room check
Ceiling height, floor, access and your consumer unit are agreed before the order is placed. You choose which side the benches go, because that is fixed at the factory rather than on site.
- Before it arrives
The circuit
An electrician runs a 16A single phase circuit to the corner where the heater will hang and leaves it ready to terminate. A room containing a sauna heater is notifiable work, so this is not a job for a competent friend.
- Delivery day
To the door, in elements
The cabin arrives flat as wall, roof and glass elements with the fittings boxed. Check everything against the parts list in the manual: Harvia ask for missing parts to be reported within 14 days, and the day it lands is the easy time to find out.
- Build day
Two people, working from the manual
Wall elements up, glass elements in, roof on, benches and heater guard fitted, then the electronics. Every screw fitting is pre-drilled. Harvia are explicit that you need an assistant and reasonable manual skills. We can arrange installation instead.
- Before first use
The electrician returns
Heater, control unit, bench sensor, infrared output and lighting are terminated, then the circuit is tested and certified. You should be handed a certificate.
What owning one actually involves.
The handful of things that decide whether this is still in use in year three.
The PRO-D2I runs the heater, and a separate output runs the infrared radiator. They are used together or apart, which is the whole point of a hybrid: a full sauna at the weekend, twenty minutes of radiant heat on a weeknight.
Harvia say it plainly: pitch pockets can appear in spruce and are not grounds for return. If one is near the surface, heat softens it and it weeps. Acetone on a rag takes it off, or let it harden and scrape it. Worth knowing before it happens rather than after.
Harvia's own advice for a cabin left idle. An unheated timber room in a house that breathes is where mould starts, and one cycle a month prevents it.
Nothing else inside. Bare timber in a sauna is meant to stay bare, and detergents leave a film that bakes.
The running costs, with the working shown.
The purchase price is public; the running cost rarely is. Ours are published with the assumptions stated, so you can check the arithmetic and change it for your own tariff.
about £1.32
Heat up: 3.6kW for 1 hour is 3.6 kWh. Holding: 1 hour at roughly 40% duty is 1.44 kWh. Total 5.04 kWh at 26.11p is £1.32.
about £137
104 sessions at £1.32. For comparison, the same arithmetic on an 8kW outdoor barrel comes to about £325, and that is before the weather gets involved.
about 7p
350W for 45 minutes is 0.26 kWh. There is no warm up, so the whole session is the whole cost. This is the number that decides whether a hybrid earns its place.
Assumptions: electricity at the Ofgem price cap unit rate of 26.11p per kWh, 1 July to 30 September 2026, including VAT. Figures are calculated from the rated outputs, 3.6kW for the heater and 350W for the infrared radiator, not measured on an installed cabin. An indoor cabin in a heated house loses far less than an outdoor one, so these are closer to the truth than the same sums on a garden sauna.
What you have to do, and what the rules require.
Everything you have to do, and how often.
| Job | How often | Who |
|---|---|---|
| Install and certify the circuit 3.6kW draws about 15.7A at 230V. Harvia publish the Delta D36 as 230V single phase on a 16A fuse with 3 x 2.5mm2 cable, or 400V two phase at 2 x 10A. The set ships with 4 metres of 5 x 2.5mm2 silicone cable. A room containing a sauna heater is notifiable electrical work in England and Wales. | Once, before first use | A qualified electrician |
| Restack and inspect the stones Lift them out, discard any that are cracked or crumbling, and restack loosely so air moves between them. Tightly packed or broken stones make the elements work harder. | Yearly | You |
| Heat it even when you are not using it Harvia recommend one heating cycle a month if the cabin is out of use for a while, to keep mould from forming in the timber. | Monthly when idle | You |
| Air it after use Leave the door open and the ventilation slit clear until the room is dry. Trapped damp is what marks benches, not heat. | Every session | You |
| Wipe the benches down A damp cloth and warm water only. Harvia name their own sauna cleaner if something stronger is needed; nothing film forming. | Monthly, or after heavy use | You |
| Deal with resin if it appears Pitch pockets occur in spruce and cannot be seen during sorting. Leaking pitch comes off with acetone on a rag, or leave droplets to harden and scrape them carefully. Harvia state this is not grounds for return. | As it happens | You |
Where this comes from.
Regulation and guidance, linked so you can read it yourself. None of it is our opinion.
- A room containing a sauna heater is notifiable electrical workApproved Document P, 2013 edition
- A sauna heater must not be protected by a residual current device, while other circuits in the room must beBS 7671 regulation 703.412.5
- Delta D36 is 3.6kW, 230V single phase, 16A, 3 x 2.5mm2Harvia, Delta D36 product data
- A hybrid sauna combines a traditional heater with separately controlled infrared panelsHarvia, hybrid saunas
- Electricity unit rate of 26.11p per kWh, 1 July to 30 September 2026Ofgem energy price cap
- Assembly needs an assistant, a 230cm room height and a 5cm gap from the wall; pitch pockets are not grounds for returnHarvia Family All in Set installation instructions, version 04/25
Every figure the makers publish.
- Warranty
- 2 year cabin and heater warranty
Cabin figures and the contents list are from Harvia's own installation instructions and floor plan for the Family Small Infra+, article 1-054-141, version 04/25. Heater figures are Harvia's published data for the Delta D36. Where a figure is ours rather than theirs, it says so.
What arrives, and what does not.
- The cabin as elements: six wall elements, two roof elements, three pieces of 8mm toughened glass including the door, and the black cover slats and frames
- Three benches, a bench foot, backrest, headrest, heater protection grille, floor grid and ventilation slit
- The Harvia Delta D36E 3.6kW heater with Finnish sauna stones
- The PRO-D2I control unit, the O-F2 bench sensor and the PRO-DA-CU output that runs the infrared
- One VitaMy 350W infrared radiator with its cover and frame
- An RGBW lighting strip built into the roof support, a 40W white LED set, and 4 metres of 5 x 2.5mm2 silicone cable
- Door handle set, door hinges and magnet, installation material and the printed instructions with the parts list
- The electrical work. A 16A circuit, run, terminated and certified by an electrician
- Assembly, unless you ask us to arrange it
- Any building work to the room itself, including flooring and ventilation
- Delivery. It is quoted for your postcode and confirmed in writing before dispatch
Reasons to buy something else.
Not the finished height, the height needed to build it. The wall elements are tipped upright during assembly and there has to be room to do it. This is the most common reason an indoor cabin has to go back.
Harvia require a gap from the wall. A cabin pushed tight into an alcove traps moisture behind timber that was never meant to sit against plaster.
The infrared radiator, its output module and the control that runs both are a real part of this price. The plain Family Small does the traditional half without them.
Harvia ask for a dry room with air circulation. A sauna does not fix a cellar; it makes the problem worse and puts a timber cabin in the middle of it.
If any of these apply, say so and we will point you at what does suit you, including when that is a cheaper product or one we do not sell.
What we know, and how we know it.
Not a rating. A record of where every figure on this page comes from: what we have checked against a published document, what a maker states and we have not yet checked, and what is still open.
- Dimensions, construction and contents
-
Verified
External dimensions, wall element thickness, glass sizes, bench sizes and the complete contents list are taken from Harvia's own installation instructions and floor plan for article 1-054-141, version 04/25, which also names Harvia Austria in Vöcklabruck as the maker.
- Infrared and control
-
Verified
The VitaMy 350W radiator, the PRO-D2I control unit, the O-F2 bench sensor and the PRO-DA-CU output are named in the parts list by article number.
- Electrical supply
-
Information not yet published
The 16A figure is Harvia's published data for the Delta D36. The set ships the D36E, the version driven by a separate control unit, and we are confirming in writing that the connection is identical before this page becomes buyable. The 15.7A current is our own arithmetic from the rated output.
- Capacity and weight
-
Information not yet published
Harvia do not state a person count or a packed weight for this cabin in the documents we hold, so this page states bench lengths instead of a number of people. Both are being asked for.
- Warranty and lead time
-
Information not yet published
The warranty term, how it is administered in the United Kingdom, and the lead time from the factory are being confirmed with the distributor and are not published here until they are.
These states move as the evidence does. When a figure is measured on an installed cabin, by us or by an owner who will let us, it moves from stated to verified and this section says so.
Weighing this against another sauna? Let us do the homework.
Choosing between two saunas takes evenings of research, so let us carry it. Name the other one you are considering and we will send a straight comparison, including where the other one wins.