Why do all of the microwaves that are used in our houses opening from the right side to left side? I've never seen any that do the opposite. I called LG company and asked them why and I got an answer in a week by email indicating that the first design that they did was in this structure and style.
Because the control panel is on the right.
Microwaves have the controls on the right to favour right handed people (similar to the placement of control panels on pre 1990's televisions.)
Placing the hinge on the right would make for a very awkward design as it would be near the middle. If you wanted to stir your food and adjust the controls at the same time, you would find the door bashing into your arm. Having it on the left means it is at one end of the equipment, so when the door is open there is no obstruction for an operator moving between controls and food.
I would guess it's because the design fits better for right-handed people.
According to Wikipedia: "Studies suggest that 88–92% of the world population is right-handed".
Microwave doors open such so that the user can insert dishes and glassware with the right hand, while holding the door with the left hand if necessary. The user needs more precision to control that which is being inserted. Afterwards, the user can close the door with either hand.
With a microwave, we are managing hot foods and drinks. Extra safety and precision are important.
It's true that a right-handed person can successfully handle dishes using the left hand. But a cup, for example, certainly could use more skill — especially if it contains a hot drink.
I think making a microwave door hinge at the bottom center (like that of a conventional oven) would solve the right-hand / left-hand argument.
Also: We are trained to move left to right, mainly because that is how most of us read and write. Therefore, if the keypad was on the left, that would suggest that you would have to key in the settings before inserting the food.
I don't thing it as a question of hinge. In my opinion it is a question of control.
As some other person has noted, the majority of old TV sets, even before remotes, have had the control knobs to the right.
It is control which commends design. Microwaves operations demand visual perception plus hand manipulation; 90% of population is right handed; so, in order to not interfere vision and hand operation, right side controls seem logical.
As a left handed person I know the feeling of misfitting in a right handed world, anyway these obstacles it are not -usually- life threatening issues :-)
PS TV sets abandoned this design when remotes became the norm.
It's simply due to biased assumption that most people are right handed and kitchens have been designed to accommodate the "standard" design.
Some have a reversable door. Some have pull-out doors. Some have a top-open door. Few are designed with a "left access design". They can be, but they just are not. Yes, this makes it inconvenient for everyone, not just left-handers, who have a microwave up against a fridge, or wall or a counter-top obstructing the right side.