Zippers: a big issue with me.
Note if a company won't honor the warranty on their zipper but honors everything else, I consider this a huge red flag.
I like the the T zip style zippers that are found on about half the chambers out there. They use plastic air tight zippers to keep the pressure along with a mechanical or structural type zipper on the outside too. The only thing I didn't like about their T zipper is that I have to maintain it by lubricating the docks right on the end of the zippers more often as they tend to stick a little and don't completely slide shut otherwise. What is different about their zipper is that it doesn't have a bladder that compresses against it to make the seal where the zipper compresses against the bladder because of pressure. But, their is no maintenance on those mechanical zippers but creating a seal can sometimes be more difficult than using just an air tight zipper.
Zippers are the biggest complaint of ALL THE HYPERBARIC CHAMBERS THAT I GET COMPLAINED ABOUT outside of the Off-gassing issues (that smell people always call me about after they get with some of the chambers.
Almost every week someone complains to me about zipper malfunctions. Zippers getting jammed from not oiling them. Some people dong get the oil less zippers and get lazy and wait till the zippers have too much friction and get stuck. Getting stuck when a kid is inside screaming because the zipper is jammed is usually the worst thing I could hear. People are calling and yelling at me like I am the one who needs to be blamed. So that is why I am making a whole page on zippers so people can know up front about zippers before they buy a hyperbaric oxygen chamber.
If you want a cheaper zipper, you must lubricate it after every 50 uses or more if you don't want any friction.
Some zippers require absolutely zero lubrication or maintenance for the entire life of the zipper.
But, they cost a fortune and you gotta send it back to get fixed that can usually cost up to 250 to fix or replace it plus shipping it both ways back and forth. The zippers you gotta oil seem to last forever if properly oiled but the non oiling zippers, you might have to change them once or twice over the lifetime of the HBOT chamber, but makes the experience much easier as they are much higher quality.
Note: When I refer to zippers being oiled, I mean they will have to need to have silicone applied to the docks.
Cheap zippers fray and do not go all the way to the end over time... you gotta pull on them much harder as they age to get them tight at the ends.
Some have 3 zippers, some have 2 zippers. Depending on the type, as they age, they can get very stiff and you have to shove your middle finger to manually push push all the way up till its 100% closed and if you can stick a pen tip through it, then it won't inflate at all. Then you gotta deflate it because it wasn't 100% closed in the first place and then it takes you about 5 to 6 minutes of wasted time time after 3/4 psi before when you realize it was not zipped totally… about 3 minute to bring down and 3 min to bring back up
The ones with 3 zippers at each end(total of 6) end helps you get in alone. If any of the zippers have a pin hole area to leak, it won't inflate.
The higher the tooth count the stronger the zipper. Tooth count is teeth per inch. The smaller the teeth the stronger the zipper will be because there will be more teeth per inch.
Make sure you know the tooth count. Is it a 6 tooth zipper? I always look for a 9 count or 10 tooth zipper. The higher tooth count the better. But, if it is a lubricated type zipper, you might want a lower number for less getting stuck. Not always the higher the tooth count is better. Make sure you know the type and gauge of the zipper. Know also if it has the zipper catch buckles and other bells and whistles that the cheap high tooth count zippers don't have. Having the catch buckles help for over travel prevention. Some get loose just like an old coat where the zipper wears out at the end tips. Metal catch buckles are always better than plastic ones. For the prices, seems like they would all use metal. I don't like to cut costs and features unless I really had to. It will be a mess in the long run.
Off Tracking: The next biggest complaint
Off tracking can cost about $250 to $1400 to send it back to get it back on track. It's a huge expense and you'll be out for about 10 days till you get it back. Again, make sure you know the potential zipper problems and history or at least know that your hyperbaric chamber has a quality zipper based on the "usage" you will be having. Also, zipper tooth size and if it is a fine or thick tooth track type affects if it can get off track in the future. Most problems happen with tooth counts are small and the tracks are fine. I have the least problems with the thick zipper tracks. Some zippers stay air tight for much longer than others. But again, the problems even with the cheap ones don't happen usually for the first 2 years anyway so not many people know about all these problems. It's usually the ones that are out of the warranty period.
I would always make sure you know if you are getting a chamber with a stainless steel slider vs the black zinc sliders. The stainless steel is 20 times stronger than the zinc type. This is a common failure place where if the slider is not completely closed the zinc type can break.
Note: even if the dealer is giving a warranty on it. Who cares if it is harder to zip up and the zipper leaks air. Many people are paying top rental fees on Hbot chambers that have been refurbished so much but people don't know it because they don't know what to look for.
Cheap zippers: You got to spend more time manually sealing the air tight zipper and you have to massage it and manipulate the seal so the zipper flows right. The seals under the zipper can give problems as well on the cheaper ones.
The last thing people want is to spend too much time massaging and using your hand to push the zipper so the pressure on the track (usually the thinner types). The less work you have to do to get the session started the better, in my opinion. All take some work but when you got to spend minutes longer is when it becomes a burden.
Questions to ask about hyperbaric chamber zippers.
What type of zipper is on the chamber?
How many zippers on each chamber?
What zippers are more user friendly? Knowing this can mean zipping it up quickly versus massaging it for a little more time.
What is the overall length of the zippers? 68 inches is the longest
What zipper configuration will last longer? Some zippers last many years. Others you might have to replace them every so often.
What type of gasket is used between the zippers?
What manufacturers don't want people to know about their chambers.
The warranty on some hyperbaric chambers do not cover any defects of the zipper if you don't call up the manufacturer with one week of getting the chamber. Be real. How does a zipper fail the first week? Seriously! And if you call about a zipper that is not working right months later they might try to accuse you of misuse, or you didn't store it right. Be sure to read their warranty page and make sure you know everything that is covered before you buy, especially new companies. See my page on warranties to make sure you are getting what you expect.
Note: Make sure the manufacturer agrees to the 1 week, 2 week or whatever days no questions asked FULL refund return policy in case you get a chamber and decide to upgrade a size or simply return it if you don't like it. Some companies won't do this but the companies that have been around the longest have always stood behind their products.