Sirui HC-70 Dehumidifier

Sirui Dehumidifier Review

Sirui HC-70 Dehumidifier
Sirui HC-70 Dehumidifier

One of the hazard of living in coastal region like ours is high level of humidity. Hot and humid weather we have, is perfect breeding ground for the fungus. The relative humidity (RH) here is around 90% RH during most of the year. When exposed to moisture or high humidity, fungus easily grows on your lenses and are almost impossible to clean. The fungus obviously degrades the optical image quality and very difficult to repair successfully back to original state.

Sirui HC-70 Dehumidifier
Sirui HC-70 Dehumidifier

Even electronic circuits don’t fare well in humid conditions and malfunction or shut down. Since prevention is better than cure, for fungal damage, there are several methods to avoid fungal growth. I have covered them in my earlier blog here – Camera’s Worst Enemies – Humidity, Fungus

Dehumidifiers are the easiest and safest way to prevent fungal growth. Most Dehumidifier cabinets use what is called thermoelectric cooling technology to reduce the relative humidity of the air inside them. Dehumidifiers are extremely effective, and can reduce the time you spend on modifying your camera’s environment, they also generally draw insignificant amounts of electricity while doing the same.

My first dehumidifier was Kalabhai’s Digi Cabi. Even though it was advertised as manufactured by Kalabhai in Mumbai, other than his sticker on the machine, every other part was made in China. This analog dehumidifier was pain to adjust. A hairline shifts of the rotary adjustment dial used to change the setting vastly.

Sirui HC-70 Dehumidifier
Sirui HC-70 Dehumidifier

I soon upgraded to Ailite brand of dehumidifier which was again made in china with a very awkward motto printed on the cabinet – WETIS MOISTURE PROOF. Despite such a funny motto, it worked well. Soon I outgrew it, and upgraded it over next few years, as my camera gear started filling it up. So from 40 litres, I went to 90 litre one, which few weeks after purchase developed problem with power supply. The unit was replaced by seller. I also did test another brand which was available in India, Benro dehumidifier. I found the cabinet was much flimsier to Ailite. With the purchase of 500mm lens I had to upgraded to Ailite 130 litre, which is what I have at present.

Ailite & Benro were the only two models which were available till now near my place. Both brands do suffer from occasional component failures. Being Chinese products sold in India, they all have only one-year warranty and are difficult to service as we don’t have service centers. It is too bulky to carry the whole cabinet and get it repaired. Main dehumidifier component as well its power supply are the major cause of breakdown in both these brands.

Few days back when I received news that Anish George, one of my favourite camera dealer from Video Links, Kannur was getting new brand of Dry Cabinet – Sirui, I asked him to send one for review. I am familiar with Sirui as I already have used their excellent carbon fibre tripod. Recent Singapore trip I got one more of the tripod from the same company. They are considered Gitzo replacement at ¼ the cost. So I asked Anish to send me a cabinet to test. Few days back he sent me 70 Litre version – Sirui HC-70 Electronic Humidity Control Cabinet. Packing was excellent. Even though it was 70 litre cabinet, but it was physically looking larger than Benro 88 litre cabinet. So I sat down with specification to check the internal volume. Here are the results

Sirui Dehumidifier hinges
Sirui Dehumidifier hinges

Sirui HC-70 Internal Dimension was 24 x 14.4 x 11.6 inches which works out as 4009 inch3 or 65.7 litres. Benro Dry Cabinets LB-88 Internal Dimension was 14.8 x 13.4 x 18.9 inches which works out as 3748 inch3 or 61.4 litres. So Benro is clearly cheating here. It claims to be 88 Litre, but has less internal volume than 70 Litre Sirui! If you notice the side by side comparison photos in this review, you can notice that Benro 88L is significantly smaller than Sirui 70 L.

Once I opened a well packed cabinet and found it has an extremely well built metal body. This cabinet enclosure is constructed from welded 1.2mm-thick cold-rolled steel. It was heavier and very much sturdier than Benro as well as Ailite. There were two plastic shelves which are adjustable vertically in their spacing. Trays were made out of tough plastic and felt very sturdy and can slide out smoothly. All trays came with a foam material mat on top to prevent scratches on delicate equipment.

Sirui Dehumidifier Handle with Key
Sirui Dehumidifier Handle with Key

The front of the cabinet was tempered glass with a steel handle. The door can be locked with a key. Unlike Benro & Ailite cabinets, Sirui cabinet keys are unique to every cabinet. So if your friend brings his Sirui cabinet keys, he can’t open your cabinet. Whereas, other cabinet provide identical keys to every cabinet they sell. On the back of the cabinet, there is a removable power cable with 3 pin 5amps socket. Box also contained an instruction manual and a warranty card. Sirui provides 6 years’ warranty on the cabinet (3 years’ warranty on electronic parts). The cabinet has four legs which are individually height adjustable legs, so as to make the cabinet stand perfectly still even on an uneven surface.

Sirui Dehumidifier Control Panel
Sirui Dehumidifier Control Panel

There is a control panel at the above the front door of the cabinet with display which tells the Relative Humidity reading in %, temperature reading in Centigrade or Fahrenheit. There are 4 buttons. One is Lock, other is Set and middle two up & down buttons are for adjusting humidity values. Once you press Lock for a brief duration the lock symbol disappears and you can now set the required humidity using the up and down buttons. Once the desired RH is reached you can lock it using the lock button. I suggest 45% RH as anything between 40-50% RH is ideal for camera equipment. Remember the reading has accuracy of + /– 5% RH. Too much of dryness by lowering humidity to less than 30% RH may lead to drying up of oil components and cracking of rubber or plastic parts on your equipment.

Just to be sure use another hygro meter to cross check the humidity which is shown by the cabinet. I used HTC 288 CTH thermo hygrometer to cross check this cabinet.

After connecting the cabinet, I left it for 4 hours to settle down and absorb all the humidity which was built in during transport. The factory setting of the humidity was 25%, which is too low and raised it to 35%. At the end of the 4 hours I checked the humidity has actually dropped from original 62% RH, to 35% RH. Then I placed my 2 bodies and several lenses to check the performance.

Humidity control component box
Humidity control component box

As I opened the cabinet I noticed interior of the cabinet was having a peculiar chemical smell. The cabinet is fitted with photocatalyst Titanium dioxide (TiO2). It is used as microbicide. Titania (TiO2)-based nanocomposites subjected to light excitation are remarkably effective in eliciting microbial death. So bacteria and fungus are eliminated by actually killing them. You can check more about it in this scientific paper published in prestigious science journal Nature (http://www.nature.com/articles/srep04134)

Thermoelectric dehumidifier mechanism
Thermoelectric dehumidifier mechanism

Most dry cabinet manufacturers (both Ailite & Benro) use Thermoelectric cooling technology. Thermoelectric dehumidifiers use a Peltier heat pump to cool a surface and condense water vapour from the air. The condensed water from inside the cabinet is taken out by absorbing sponge on the draining channel and sent out. The design is simpler but, because of its relatively poor coefficient of performance, this design is mainly used for small dehumidifiers. If the electricity stops then the thermoelectric cooling pad will stop working thus allowing the humidity to build up. Imagine going on holiday for 2 weeks and coming back to find that your power had tripped, exposing your camera equipment to whatever levels of moisture allowed into the dry cabinet.

Sirui dehumidifier mechanism
Sirui dehumidifier mechanism

Sirui for its dehumidification uses molecular desiccant sieve (MDS) which is under the micro-computer control. This desiccant is stored inside the Humidity control component box.

When the Cabinet humidity is higher than the set humidity, the MDS absorb the moisture inside the cabinet, thus dropping the cabinet humidity. In that process they get saturated. This process is similar to Silica gel. Once the humidity is reaches closer to the set humidity, vent connecting the interior of the cabinet is shut down and the exhaust vent at the back of the cabinet is opened by micro-computer. The chamber holding the MDS is now heated with built in heater and that releases the moisture inside MDS, which escapes outside. The dried MDS is now capable of absorbing water again. The vent at the back shuts down and the internal vent opens if the humidity is not yet reached to the set point, thus exposing the MDS to the interior of the cabinet. Dried MDS again starts absorbing moisture and the cycle continues.

Benro 88L, Sirui 70L & Ailite 130 L Dehumidifiers
Benro 88L, Sirui 70L & Ailite 130 L Dehumidifiers

These molecular desiccant sieves are hydrated aluminosilicates (zeolites) of the alkali earth metals. They have a high affinity for water and have the capability of adsorbing and desorbing it without damage to their crystal structure which makes them useful as desiccants.

This process is totally different from the one, Ailite and Benro which uses Thermoelectric cooling technology. It has advantages. If the electricity shuts down in Thermoelectric cooling cabinets, dehumidifier function stops working as electricity is needed to heat the Peltier element and to create differential temperature between interior and exterior. Without electricity humidity raises rapidly inside the cabinet as the same absorbing sponge which sends the moisture out of the cabinet now without electricity allows the moisture to come inside and equalize with exterior.

Benro 88L, Sirui 70L Dehumidifiers
Benro 88L, Sirui 70L Dehumidifiers

In Sirui Cabinet, as the molecular desiccant sieve is not dependent on electricity to dehumidify, it continues to reduce humidity for a longer duration, Sirui claims up to 24 hours. Sirui also uses this process to conserve electricity. As soon as the humidity reaches the set value, the micro-computer drops to power save mode and shuts the electrical supply to the Humidity control box. It will not be activated till humidity raises to 5%RH above the set point. While cabinets which work on Peltier technology need 24 hours electricity and try to maintain humidity, Sirui takes long naps to save electricity.

To actually test I used my Ailite cabinet and a borrowed Benro 88 litre cabinet with Sirui. I set all their humidity to 35% RH and once they reached that I switched off the electricity of all of the cabinets. I switched it on after every hour (for few seconds to check humidity) without opening the door of the cabinet for 6 hours. At the end of 6 hours Sirui has risen to 41% RH and Ailite was at 53% RH and Benro was at 55% RH. Room humidity (outside all these cabinets) during this period was 62% RH. Sirui beat others hands down in this test.

Benro 88L, Sirui 70L Dehumidifiers
Benro 88L, Sirui 70L Dehumidifiers

Since Sirui uses pretty aggressive power saving option, it saves lot of power and the cabinet really frugal in power consumption. Sirui claims 1.3-3.4 kW/month electricity consumption for this 70 litre cabinet. Benro and Ailite are usually rated at 5-10kW/month as they need a constant fan rotation. Sirui dehumidifier does not use any fan and thus is silent, whereas the Thermoelectric cooling dehumidifiers need constantly running fan which also increases their electricity consumption.

While in power save mode, Sirui looks almost fully switched off without the normal blinking green LED light. I think they should have provided another light which signalled that it is in power save mode. Only way I could make out is by a very faint LCD panel read out which still shows the humidity reading without any back light.

So here is my verdict. Even though almost all dehumidifiers available in India are from China, Sirui stands apart with following few points.

Pros

  • Very sturdy high strength well-built metal cladding for the cabinet.
  • Innovative dehumidification mechanism
  • Long term maintenance of low humidity in case of power failure.
  • Nice sturdy plastic trays with soft materials to support delicate equipment.
  • Using TiO2 microbicide to further resist fungal growth.
  • 3+3 years of Warranty.
  • Fan less and silent.
  • Extremely low power consumption.
  • Internal volume is larger than other brands of the same size.
  • No annoying bright LED display to spoil your sleep 🙂

Cons

  • TiO2 might be harmful to health if inhaled for too long.
  • Power saving mode looks almost fully switched off.

If you are looking for a very sturdy dehumidifier with an innovative technology and 6 years of warranty with extremely low power consumption, Sirui fits your requirement perfectly.

This is my first detailed product review of this kind, in my blog. Please send your comments and suggestions to improve it.

Disclosure: I was not financially compensated for this post. I received a sample for review purposes. The opinions are completely my own based on my experience. I was not required to write a positive review. Some of the photos of the cabinets are used from Sirui website. The dehumidifier mechanism was drawn by me, may not be technically accurate, but only used for illustrative purpose. Building a DIY dehumidifier based on my drawing may not work 😉

36 thoughts on “Sirui Dehumidifier Review

  1. I was planning to buy one. I need not think on which one to buy now. Please help me in buying one. Tell the name of the dealer or their phone no. A big thank you for your detailed review .

  2. I have been using the SIRUI 50L dry cabinet for quite sometime and so far so good. It was nice dealing with Anish as well. Thanks four your indepth review. Do you you have any suggestions for the stabilizer i should use for the dry cabinet. Was wondering which stabilizer should i opt if at all i need one. Kindly assist. Thanks in advance.

  3. Dear Vinu J George,
    Thanks for your compliments. Hope review was useful for you. Since it is a SMPS based supply. there is no need of any stabilizer. Only precaution I take is disconnect from the mains when there is lot of lightening & thunder. Other than that you don’t need any other precaution. make sure you have properly grounded 3 pin 5 amp electrical connection, that should take care of it.

  4. Dear Azad Sheikh,
    I don’t think TiO2 is not that bad. Since you are not keeping the box open too long TiO2 will not be reaching your lungs so far. The TiO2 remains inside the dehumidifier and not spread outside. You need not worry that much. Titanium dioxide makes a very effective sunscreen in creams and lotions, and is one of the safest options available. It is used in many of these cosmetics and found that it had no ill effects.

  5. Hi Krishna Mohan,

    I was doing rnd on this product. After reading your review, I bought it – a 50L cabinet from Anish and I am using it for the last 2 weeks and its good.

    I have set the humidity value to 45 and I believe its the right value. is it fine ?

    Other than camera and lens, would you advice keeping the external hard drives (the one with power-supply ) for long time in the dry cabinet – what you think ? will it damage the Physical components of the hard disk ? or any other damages ?

  6. Hello Dr. KrishnaMohan,
    Thanks a lot for your indepth analysis on the Sirui HC 70.
    My only query is that can I keep my biggest lens Canon 200-400 with 1.4TC . Lenght 400mm/15.5″ and height 200mm/7.5″.
    Thank you in advance

  7. Dear Sougata Ganguli,
    70Liters is small for 200-400, you need to go for 110 liter version. I have a 500mm f/4 which fits in the 110 Liter version comfortably.
    Thanks for contacting me 🙂

  8. Wonderful review of a product I was searching for. You could have added the dealers link too. Thankyou Krishna Mohan for taking time to help photographers.

  9. hello, I have just bought a Sirui 70 Ltrs cabinet. I have noticed that when I open the cabinet after the set moisture value is acheived it feels cooler inside . Is this normal?

  10. Will a Canon 100-400mm lens fit in the Sirui 70L Cabinet?
    how does one buy this in Mumbai pls?

    Thanks

  11. dear sir,
    firstly thanks for depth review of sirui brand dry box.
    I have purchased sirui HC 30 model with 30 litre capacity for 9.8k.when I try to set RH 49%,it is not showing correct 49.
    it is showing 43 or 52 etc value.Is this a malfunctioning? SIrui said that + or – 5% is accuracy.is that due to this + -5% accuracy?

  12. Very informative review.
    i have a Kalabhai 40 litre dry cabinet.
    But i would like to add on another dry cabinet for my 600mm f4 FL. which size would you suggest.
    Thanks in advance.

  13. Wonderful, informative and detailed easy to understand review….I am in the process of evaluating various option…am sure your review will help me make a proper decision.
    Thanks

  14. Dear Mr. Krishna mohan. I have bought the HC 70 one. At times there will be power fluctation at home. So i thought of using a small stabilizer – like that of LED tv. Is that fine. Please advice

  15. ear Sriram,
    No need of any stabilizer for the dehumidifier. It has built in SMPS like our computer. Even if there is a fluctuation it can tolerate as it DC input and NT AC like TV & Fridge. It can withstand power down for 4-6 hours provided you don’t open the door too often during power shutdown
    Thanks for contacting me

  16. Thanks for the detailed review …Last saturday i have ordered
    50 ltrs from Anish and i think it has already reached to my place. Thanks Krishi Sir ….

  17. Hello Dr. KM Sir,
    Your indepth review helped me decide in favour of sirui 70 ltr.
    I purchased one daybefore yesterday from Mr Sudhakar Shenoy of Mahaveer Agencies, Mangaluru.

  18. I have a Sirui HC 110 dry cabinet,
    which worked perfectly well for the last 3 months but now behaving erratically. When I set the RH to 45, instead of reducing the RH inside the cabinet to attain the set value, it increases it to beyond 75. I was wondering how/where to get it serviced. Are there any service centres in India to avail the 3+3 years stated warranty?

  19. Dear shakkeer,
    It is perfectly normal and that is how Sirui really works. When you keep 49%RH it stops dehumidifying at around 49% but since it uses gels to absorb moisture even if the electrical gate to the gel is cut off at 49%RH, the gel keeps absorbing humidity for a little more so it reaches 43%RH. In fact the dehumidifier does not switch on until it reaches slightly higher than 49%RH thus saving electricity. I would suggest RH of 45% and leave it as it will fluctuate between 40-50%. Yes this is the 5% fluctuation I was explaining in the review and it is perfectly normal feature of Sirui. Don’t worry anything in the range of 35-60% RH is safe for Camera & lenses.
    Thanks for contacting me

  20. Thanks very much for indepth review. Which one to buy 80 or 110 ,my gears are-D500,810 Nikon,300 mm 2.8 Nikon, 70-200 2.8, other 4 small lenses.advance thanks.

  21. Thank you for the review. Is it possible to order this on line? Where are they being sold?

    Thank you very much.
    Rajeev George

  22. Hi

    I have bought the Sirui 70 lts and is kept in the bedroom. Thanks for your detailed review which was the catalyst for me buying the Sirui/ Just one query. the drycab is kept in my bedroom for want of space. Is it ok from health pint of view as you mentioned of the effects of TI02…thanks

  23. Nice detail article while searching for some info on AILITE GP -90 model , which I bought used from one fellow photographer 5 years back who bought it from VideoLinks as told to me . Couple of months back it stopped as the power supply module is blown . You seem to have done lot of studies on humidifiers . By any chance do you know the SMPS supply specification for the GP -90 model ?

  24. Finally I bought the SIRUI HC 110 L, it is fine and spacious, but want to know the following-
    1. power switch shall be “on” 24 x 7, means when it attains the desired setting (40 or so), shall I put put the power supply “off” ? if I am not using the gear for one week or so.
    Thanks in advance.

  25. If you are not keeping anything inside dehumidifier, then you can switch off. If you have any lens inside, don’t switch it off. Even though power is on, the dehumidifier switches on only when the 40 RH drops to 45 RH and not before that. So it saves a lot of power.
    Thanks for visiting my website and liking it

  26. Hello,

    Nice detail article. Just a small query. At present I have Canon 7d markii, 100-400 ISii, Tokina 11-16, 50mm 1.8 and Canon 550D body. I think these will fit to 70L. But will it be enough for a long lens like 500 F4?

    Thanks in advance

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