Safety about windows

Question

1. The house which I rent and am living in has a kitchen on the first floor, where there is a window facing the yard with its lower half covered by security bar and screen, like this one .

   Is it safe to keep the lower half window open at night during sleep?

   The top looks like not easy to be pulled down. Is the top half window usually fixed to the top of the window?

   I am hesitating to close and lock the window, because if the window is closed during the night, I feel the air in the first floor especially near the kitchen will become a little worse gradually. I guess maybe it is because the gas normally leaks a little from the range, and the pilot fire is kept on?

   So shall I close the window for safety or keep it open for air? Note that except during the coldest day, we don't turn on the central air system.

2. For window of bedrooms on the second floor, do people usually close them at night during sleep for safety?

3. I was wondering if the security bar usually only cover the lower-half of a window, and if it is enough or covering the whole window will be a better choice?

For reference, I am living in a city in the United States, where safety is usually a concern.

Answer 1

First, get your possible gas leak checked out right away. Call the gas utility company that services your house and ask them to come and check for a leak. Most gas companies will do this for free and quickly, because it is not good for business when their product kills people. If you suspect any gas leak at all, you should get it checked.

Second, whether your security bars are actually secure depends on how they are installed. Are they fastened securely? If you have a sash window like the one in the picture, usually both sashes can be moved up and down, but it's possible that in your installation the upper sash was not designed to move or has been fastened in place.

Regarding closing windows on upper floors for safety: usually only ground-floor windows need to be secured, as thieves tend to look for the easiest opportunity, and the challenge of climbing into an upper story window probably isn't worth it. Take a walk around your house, think about the top few ways you might get in if you lost your keys, and secure those things first. And let yourself enjoy a little fresh air at night. :)

Answer 2

"I am living in a city in the United States, where safety is usually a concern."

I assume you are asking in regards to break-ins. The main question is: how relatively save is your neighborhood? Yes, we all worry about this, but it's often an over-sold concept (the home alarm industry thrives off of it).

The photo is a of a double-hung window where both panes are usually moveable. However, it'd be pointless to have bars on only half the window if that was the case, so perhaps the top one is bolted shut.

You can buy window locks at almost any hardware store that allow you to keep the window partially open, but no further.

As for the second floor...I suppose burglars could carry around ladders, but you don't usually see that too often.