Dynamic Alpina (Costco): the specs, and the model number that gives it away

By Md Hasan · Published 2026-09-24 · Editorial policy

Nothing on this page earns us a commission. Costco runs no affiliate programme, and Golden Designs — who make this sauna — appears to run none either; we wrote to ask on 2026-09-23 and had no reply by publication. We cover it because our readers are searching for it. Full disclosure

The answer in 10 seconds

Costco price	Online only, new this season, item 2089888.	$4,999.99
The direct equivalent	Golden Designs sells GDI-B004-01 as the “Arosa 4 Person Barrel”. Costco’s is GDI-B004-02 — same chassis number, different suffix.	$7,999.00
The gap	Costco is cheaper and carries the larger heater (8 kW vs 6.0 kW stove).	−$2,999
The catch nobody mentions	240V, 40 amp dedicated circuit — the heaviest requirement we have recorded on any sauna.	40A
Weight	Crated freight. Not a two-person job.	500 lb

Why this one needs a page of its own

Ask a search engine about Dynamic saunas today and it will tell you they make infrared cabins, not traditional barrels. That was true until recently. The Alpina is a traditional steam barrel carrying the Dynamic name, it is new this season, and virtually nothing has been written about it anywhere — which is exactly why we looked up its model number.

The model number

Costco lists the Alpina as GDI-B004-02. Golden Designs — the manufacturer behind both the Dynamic and Golden Designs brands — sells a four-person barrel on its own site as GDI-B004-01, the “Arosa 4 Person Barrel”, at $7,999.00.

	Costco “Dynamic Alpina”	Direct “Arosa 4 Person Barrel”
Model	GDI-B004-02	GDI-B004-01
Price	$4,999.99	$7,999.00 list
Heater	Harvia Wall 8 kW traditional stove	6.0 kW stove
Capacity	4 person	4 person

Same chassis designation, different trim suffix. On the numbering these read as siblings rather than unrelated products — and the Costco one is $2,999 cheaper with the bigger heater.

What we are not claiming. A shared chassis number is not proof of an identical sauna. The suffix differs, the Costco unit is badged “Elite” and lists a stainless steel roof and bronze privacy glass the Arosa listing does not, and Golden Designs’ figure is a list price they may discount. We are telling you the numbers line up and where to check — not that you are buying the same box.

The 40-amp problem

The Alpina needs 240V at 40 amps, drawing 8,000 watts. That is the heaviest electrical requirement of any sauna in our records: the Almost Heaven and Redwood barrels we track are 240V/30A, and the infrared cabins are 15–20A.

A 40-amp dedicated circuit is serious electrical work. It is not a socket — it is a run back to your panel, and on an older panel there may be no capacity left without an upgrade. Price that before you price the sauna. Our electrical checker shows what it means for your board, and the Electrical Reality Report puts it beside every other model we track.

Verified specifications

Costco item	2089888
Model	GDI-B004-02
Type	Traditional (steam), 4 person
Heater	Harvia Wall 8 kW traditional stove
Electrical	240V / 40A dedicated / 8,000W
Exterior (W×D×H)	80.31 x 72.10 x 83.07 in
Interior (W×D×H)	77.95 x 63.23 x 77.95 in
Weight	500 lb
Included	Stainless steel roof, bronze privacy tempered glass, LED control panel, accent lighting

Read from Costco’s own product page on 2026-09-24: source. Direct comparison read from goldendesigninc.com the same day.

What we don’t know about this one

Whether the Alpina and the Arosa 4 Person Barrel are the same cabinet with different fittings, or merely related. We have the numbering, not the drawings.
Warranty terms for the Costco SKU specifically. Golden Designs publishes warranties by product line, and retailer-exclusive variants are not always covered identically. Ask in writing against item 2089888.
Delivery reality. On 2026-09-24 Costco reported delivery unavailable to our test ZIP for this item. That may be new-product rollout rather than a permanent limit — check your own postcode before planning anything.
Whether the 8 kW Harvia ships with its standard controller or the LED panel Costco pictures.
Any hands-on assessment. We have not seen this sauna, and as far as we can tell nobody publishing about it has either.

If you own one, or you get any of the above in writing from Costco or Golden Designs, send it to hello@saunaclear.com and we will publish it with the date and the source.

Before you buy

Run the total through our true-cost calculator using the 40-amp figure, not the sticker price. Read the return terms — Costco’s are the most generous in this category and a real part of the value. And the rest of Costco’s current lineup, all 30 models with prices read the same day, is on our Costco sauna guide.

Did this answer what you came for?

Method: specifications and price read from Costco’s own product page on 2026-09-24; the direct comparison from goldendesigninc.com the same day. Costco rotates stock and pricing without notice, and this page is not part of our automated weekly check — treat the date as the guarantee. Electrical work: licensed electricians only. Spot an error? hello@saunaclear.com — corrections are published, not buried.