What makes a window move up and down?  How come some of the older windows need to be propped up with a cut off broom stick?  Why are some windows easy to open up and difficult to close?

These are some of the questions you might ask when you are selecting new replacement windows for your home.  The answer to the above questions is balances.  What is a balance or for the purpose of our discussion, specifically what is a window balance?

A window balance is located inside the window, and its primary function is to operate the sash of the window up and down.  There are different types of window balance systems available, I am going to discuss three, block and tackle, spiral, and constant force.

The block and tackle balance system has been around for years.  Many 'old line' window companies started using these decades ago.  The concept is a rope and pulley system, even the 'new versions' operate under the same premise, rope and pulley.  By operating on a type of rope and with having several moving parts, this type of balance is susceptible to breaking down over time.  Also, the tendency for this type of balance is to work easy going up or going down.  But it just doesn't have the easy of operations in both directions.

The spiral balance was introduced to replace the older designs of the block and tackle design.  This balance has a tendency to break down over time even more quickly than the block and tackle.  It needs to be lubricated with grease, and as the window remains closed, the spiral balance is open and unprotected from the environment.  This means dust, dirt, pollen, etc. sticks to the grease of the balance.  When the window is operated, all the elements of the environment act as drag on the balance.  This makes the window extremely difficult to operate in both directions.  If all this wasn't enough, the spiral balancer has different colored tips based on the weight of the sash.  So if a balance goes bad, you need to color match the tips otherwise the window will not operate properly.

There has been a newer type of balance introduced to the market, and it is called constant force balance.  This balance has very few moving parts.  It is self lubricating and many of the constant force balances are Teflon coated.  This makes operating the sash easy both up and down - most of the time, you can operate a constant force balance window with one finger. 

Another great benefit is it doesn't matter how heavy or light the sash is, the balance keeps the force of opening the window or closing the window 'constant.'  So, in this world of green and energy efficiency, you can have a triple glass window, and not have to worry about how difficult it would typically be to operate.  The triple glass gives you great energy efficiency thereby making it more of a green or environmentally friendly product.  And the constant force balance system gives you easy operation. 

Guess which balance system is in my house!