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Thermalution Battery Powered, Heated Undershirt: A Product Review

Discussion in 'Exposure Suits' started by Deep South Divers, Mar 1, 2014.

  1. Deep South Divers

    Deep South Divers Contributor

    The Thermalution runs very low voltage... And it's a DC current, not an AC. It's also very low amperage, meaning that no - it's not a safety issue.

    The connectors are gold-plated and I often ran my connectors not fully connected, since they're tough to get on and off. This left the gold-plated metal contacts in contact with the seawater or freshwater that I was diving in.

    The shirt continued to work just fine... And no, I did not get shocked.

    I very much enjoyed my Thermalution while I had it... 10°? Yes - that's a reasonable expectation to get out of the shirt.

    Keep in mind that you'll still get the initial shock of jumping in cold water as the wetsuit floods... But you can definitely feel a nice warming sensation out of the shirt... Which improves things a lot.

    Don't forget that battery life - on low power, which is what I liked to run mine at - is a little over an hour... Maybe an hour and a half on a good day. If you're planning on diving all day, you'll find the shirt's battery life to be a problem.

    Lastly - you'll still have to doff your wetsuit wet... Meaning that even if you're warm and toasty in the suit with the shirt on, you're still going to have to take the suit off in cold weather, while being wet. This isn't a problem if you have a hot shower to doff in - like at a dive site - but this shirt is no replacement for a proper drysuit, which is a joy to doff at the end of the dive... While you remain warm, dry, and toasty during the entire ordeal.

    Honestly? For $600? I recommend a good drysuit, which starts at just a few hundred dollars more. I'd say to use the money that way instead. You'll be warmer, dryer, and much more comfortable at all times. You'll also not have to deal with running out of battery on even short dive days.
  2. Bent Benny

    Bent Benny Contributor

    # of Dives: 50 - 99
    Location: Criehaven Island, Maine
    I'm not very familiar with this product, but I am familiar with lithium ion batteries.

    I don't think there is much of a safety issue with something like this other than safe handling of the batteries. I assume there is protection circuitry in the controller protecting the user from short circuits and such.
  3. guyharrisonphoto

    guyharrisonphoto ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Florida, USA
    I spoke to thermalution. They said there is no difference in heat output. Only difference is twice the battery life and wireless remote on yellow grade. Remote is good so the corded control does not have to break the seal on your wetsuit or zsemi dry. Not a question of cost if u hate diving in a Hefty trash bag like I do and prefer sleek and trim diving wet then these are great.
    Deep South Divers likes this.
  4. ZeroG

    ZeroG Divemaster

    # of Dives: 100 - 199
    Location: Los Gatos
    @Deep South Divers
    Thanks for taking the time to respond, and everyone else as well.

    Specifically Deep South. I was basing my purchase on your previous review, this same thread 2 years ago. At that time you appear to rave about this product and you're as a very experienced diver doing it professionally. You also go into all the issues with dry suits, something I've never tried. So it seemed like good advice. Now you suggest spend a bit extra and go dry?

    I have about 60 dives, live near Monterey where the water temp is 50 to 60F. Basically I'm still a bit cold, but I love diving and want it to but truly enjoyable. I have a 7mm bare with magic orange lining, and if I could just get a bit warmer I'd be happy. I don't mind spending more money to get there, but also don't want to wast money on Thermalution, and still be happy and then go dry. I figure going dry will cost me about 2.5K

    I could really use advice from a guy like you, so thanks. Again thanks for taking the time.
    Deep South Divers likes this.
  5. Pkishino

    Pkishino Instructor, Scuba

    # of Dives: 200 - 499
    Location: Japan
  6. Bubblesong

    Bubblesong ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 50 - 99
    Location: Massachusetts
    @Deep South Divers I bought two heated Thermalution shirts used that we will be trying in the pool soon. We all took Drysuit class and we hate the hot struggle in that neck ligature, self-torture device. So we thought the Thermalution heated shirt would give us just enough warmth to not need dry.
    Has your two years experience since your first review changed your mind, or other diving situations come up?
    Blueringocto_73 likes this.
  7. Pkishino

    Pkishino Instructor, Scuba

    # of Dives: 200 - 499
    Location: Japan
    Interesting choice of words.. I love my dry suit, feels weird when I dive wet.. Even Mexico/Egypt/Malta I rather dive dry santi emotion with fitting layers depending on temp.. But I would be very interested to test if the ursuit fir works under a wetsuit
  8. guyharrisonphoto

    guyharrisonphoto ScubaBoard Supporter ScubaBoard Supporter

    # of Dives: 1,000 - 2,499
    Location: Florida, USA
    Here is a practical report. I just spent 3 days doing 5 dives in California. I am from Florida and this was my first "cold" water trip. My first day, I did three dives on a boat to Anacapa. I had my old semi-dry for these dives, in 64 degree water, and did not need the thermolution as almost no water flushed through the suit and I was warm even on one hour bottom times. At the end of the last dive, though, my dry zipper failed (suit was very old) and, for the next two days (one dive per day at Catalina dive park), I had to rent a standard 7 mil that did not have skin seals on the wrists or ankles, and was that super stretchy neoprene that gets cold at depth. Lots of water flushing through by comparison to the semi-dry.. So, I used my thermolution shirt on the one hour dives where most of the time the water temp was 68 on the surface but 61 degrees at depth (80'). The dive was cold at depth, but not shivering cold. The shirt did make a noticeable difference in keeping my back warm, and by lifting my arms occasionally I could circulate the warmer water around the suit. But, the shirt could not overcome completely the flaws of the rental suit as the shirt gives a continuous gentle heat and every time water flushed through it would be cold and take a few minutes to warm up, by which time more water had flushed . . . you get the idea.

    I don't think I could have made the full dive time on those second two dives without the shirt and that extra edge of warmth to overcome the poor suit. With a good sealing less compressible neoprene wetsuit, or even better a semi-dry, I can see the shirt making a much bigger difference in even colder water.

    That being said, if I lived in California or similar cold water areas for my regular diving, I would go dry.

    For the occasional cold water trip (I loved California diving and plan to go back once a year, or if I go to the Galapagos), the thermolution would be a really good thing, but you still need a quality wetsuit to get the most benefit.

    From this experience, I would say the thermalution is good for one "thickness" of neoprene. For example, the shirt plus 5 mil would be roughly equal to a 7 mil without the shirt. But, this assumes a high quality, low compression (ie no "super stretch") wetsuit with skin seals at wrists, ankles and neck.
    Bubblesong likes this.
  9. Deep South Divers

    Deep South Divers Contributor

    I actually had to go back and re-read this thread... It's actually been four years since the original post.

    Here's what's happened: Technology.

    Specifically, drysuit technology.

    Crushed (or "hyper-compressed") neoprene has replaced trilaminates and compressed neoprene as the suit material of choice. Basically, the material has all the reduced buoyancy characteristics and thin suppleness of trilams while maintaining all of the stretch and flexibility of a wetsuit. This allows the diver to wear what is effectively a dry wetsuit... Combining a close-fitting, more streamlined suit with a fully dry experience. The stuff is tougher than trilams and neoprene wetsuits alike, too... While being easier to manufacture and not require the perfect fit of a custom-made suit. We dive them empty and devoid of any internal air - but still equalize them. They're not wetsuits - but they're not like any drysuit. They're definitely not semi-drys either.

    Latex neck seals have been replaced by tough, long-lasting, and exceedingly comfortable silicone seals that can be replaced in the field for very little cost and no downtime.

    Latex wrist seals have been completely removed, and have been replaced with tough, stretchy, inexpensive drygloves that snap on and off easily. They're dry as a desert, too... And more reliable than any wrist seal of any kind.

    Plastic zippers that are reliable, flexible, dry as a bone and practically maintenance-free have replaced the old, expensive, stiff, problematic, high-maintenance zippers of yesteryear.

    Bulky, leaky, and problematic exhaust valves have been replaced with a nonadjusting, always-open, triple check valve system that we custom-built with SiTech. They're only 1/4" tall and are slick and never leak, even in a terrible commercial diving environment.

    Warm neck collars that were once gapping and ineffective past maybe a cosmetic feature have become a part of the sealing system of the wet hood.

    The wet hoods that we're using have become better integrated into the drysuit as a system... And almost completely cover the face; think of a full-faced mask, but using a standard half-mask with a normal second stage regulator.

    In short - our drysuits have become more wetsuit-like. We've grown to love them and pine for them mid-summer. Today, in mid-September, I'm very much looking forward to water temperatures falling out of the 3mm wetsuit range. I'm virtually holding my breath for 70 degrees... These new suits are awesome, but too warm for anything above 70 or so.

    Is a powered, heated undergarment still a great idea? Absolutely. We'll be building our own soon for about half the price of a Thermalution, and it'll function better both under wetsuits and drysuits than anything in the market currently. Batteries will be hot-swappable underwater (don't even need to turn the heater off or go to the surface to change batteries), and have a ridiculous amount of heating available to the diver. The heating elements will not be made of wire and won't be detectable until the garment is turned on. In fact, we may equip the wetsuit with the elements built right into the neoprene so that the diver doesn't even have to don a separate undergarment in order to stay warm. The stuff is durable and stretchy and provides more heat than a wire.

    We'll also be offering a topside, inexpensive, instant water heater that will work off of battery power, for getting a warm washdown after a winter dive in case you want to dive wet year-round... Or in case you want to be able to rinse your head and hands with warm freshwater if you're a drysuit diver. It's truly heaven on a cold day. :)

    Up to this point I've never manufactured dive gear... All I was doing was reporting what worked and what didn't for our commercial divers. But I'm so tired of having to alter all of the gear that we buy - and try to talk manufacturers into building stuff that works - that I'm just going to start making the stuff myself.

    When? I dunno. But I'm tired of giving my ideas away for free to companies like BARE, SiTech, DUI, and more. I am ready to build my own gear. :)
    Bubblesong likes this.
  10. tursiops

    tursiops Marine Scientist and Master Instructor ScubaBoard Supporter

    # of Dives: 2,500 - 4,999
    Location: U.S. East Coast
    Well, there you go. $500 vs $3k. Your choice. Life is full of tradeoffs.

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