In recent years, home-use digital lock is getting popular. Opening a door with a pin code, a fingerprint, or a card key seems a convenient alternative fending off possible blunderous situation arises from losing door keys. Along with the convenience noticeable, however comes also safety concern.
The Consumer Council has studied 19 digital locks available in the market and compared key features between digital locks and traditional mechanical locks, for consumers to make the best choice taking account of their personal needs.
Digital locks can be categorized into two groups. The primary lock is the main locking device on a main door with a lever both inside and outside the door, while auxiliary lock, smaller in size and without lever, serves mainly as an additional security device mounted to a door with a lockset and a lever.
In general, there are four different ways to unlock a digital lock, namely, by pin code, card key, fingerprint and physical key. Models of digital lock under this review allow two to four different ways to be unlocked, with pin code and card key being the most common.
Pin coded locks require a password of at least four to six digits to open. Random pin code or fake pin code are set for most of the digital locks in this review to avoid someone breaking the pin codes by peeping or spotting the finger stains.
A digital lock using card keys comes with two to five card keys. An additional card key usually costs about HK$60 to HK$80. Only five of the digital locks under review support fingerprint authentication.
Warranty period of the digital locks under review lasts from 1 to 2 years. During the warranty period, most brands offer free on-site check and repair service for consumers in downtown area, while three brands provide such free service in the first year only. Service charges range between $350 and $550 when warranty is expired and there is a surcharge for those residing on outlying islands or in distant areas. 3 agents provide 24-hour hotline or on-site repair, but service during night time is generally restricted to emergency cases.
Some of the digital locks available in the market are equipped with an anti-panic function which allows users to open the lock by simply pressing down the lever from inside, even when the door is securely locked. Usually installed in hotels and public places, such function allows users to unlock and escape immediately when emergency such as fire arises. Such useful function could possibly be abused by culprits familiar with different design of locking devices to unlock the doors.
The anti-panic function in fact also exists in traditional mechanical locks. Industry players suggest consumers of such door lock to consider installing fire and smoke seal around the door frame, as well as automatic seal at the door bottom to fill the gap between the door and the door frame, in order to prevent culprits from slipping objects through the gap to unlock the door. Users may also consider having auxiliary locks in place to enhance security.
3 types of common mechanical locks are mortise lock, rim lock and latch lock. Mortise lock is frequently used as the primary lock on main doors, and most would lock automatically when the door is closed. It requires a matching key to unlock from outside.
Rim locks and latch locks are often used as secondary locks. Consumers may opt for cylinders with computer keys, a more complicated design as compared with the ordinary locks for a higher level of security.
Consumers should note that door lock is only one aspect of home security. Material of the main door and door frame as well as lock installation technique are also of importance, for instance, hollow wooden doors should not be used.
Digital locks and traditional mechanical locks vary in characteristics and features. Consumers may consider the following in choosing a lock that fit their needs:
- Convenience: Digital locks can be opened by fingerprints and pin codes without the hassle of missed bringing the key and being locked out. Access can be restricted by changing pin codes, invalidating key cards or nullifying authenticated fingerprints. Therefore, it saves the need to change the cylinder or the lock if a domestic helper leaves or a renovation project is completed.
- Difficulty in key duplication: Generally speaking, keys for traditional mechanical locks are easier to be copied as compared with fingerprints, pin codes and key cards for digital locks. However, to enhance security some mechanical locks manufacturers impose limitation like requiring information of the registered customers and serial numbers of the locks before making replications
- Level of Security: It is not easy to pry open mechanical locksets made of strong materials, of complicated designs or with cylinders of high level of security. Damage can be relatively easily done to the plastic panel of some digital locks than to the metal panel of mechanical locks, although digital locks being tampered would sound out alarms to scare burglars away.
- Stability: Operations of digital locks are prone to external factors such as humidity and vibrations, while mechanical locks are more stable.
Consumers who opt for digital locks are reminded of the following:
- Fingerprints of the elderly, children and people with shallow fingerprints are more difficult to be recognized. Besides, elderly and children may not be good at memorizing pin codes, so key cards are more suitable.
- Do not use water or wet towel to clean digital locks.
- Battery should be checked and changed once in a few months, in order to avoid leakage of electrolyte which can damage the digital locks.
- Replace a whole set of battery for the digital locks at one time but not mixing new and old batteries to avoid inducing leakage of electrolyte because of overloading the old batteries.
- Close the door gently to avoid shocks to the digital locks, which could shorten their life span.
- Pay attention to the changes brought to the doors by thermal expansion, and make sure door and door frame, lockcase and strike are properly closed.
- Warranty period of the digital locks usually lasts around 1 to 2 years. On-site check and repair is charged as much as $550 when warranty is expired with surcharges for those residing in distant areas. Round-the-clock repair support could cost even more.
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