Like all home appliances, sooner or later furnaces must be replaced. Though ultimately this will result in more cost-efficient heating, the process of getting a new furnace can be both expensive and stressful. For that reason, it's important to make sure that things get done right the first time around. If have plans to replace your furnace, read on. This article will present two vital questions to ask your installation contractor.

1. Do you intend to do a heat loss calculation?

The heating power of a furnace is measured in terms of British thermal units, or BTUs. Don't let yourself make the common mistake of assuming that your new furnace needs to have the exact same BTU rating as your old one.

There are several reasons why a furnace with a different BTU rating may be the best option for you. For one thing, it may be the case that the furnace you're replacing was incorrectly sized to begin with! This is more common than you may think, especially as the optimum heating conditions of previous generations weren't necessarily the same as yours. Similarly, your home's heating needs may have changed for more objective reasons, such as:

• room additions
• improvement in window and/or door insulation
• installation of supplementary heating devices (fireplaces, wood stoves, etc.)

Insist that your heating contractor perform a heat loss calculation before you decide which model is right for you. Such calculations help give you an accurate picture of your heating needs by factoring in all of the ways in which your home loses heat. The results will make it much easier to select the furnace most appropriate to your needs.

2. Will you modify ductwork as needed?

If you live in an older home, you're probably familiar with the problem of certain rooms getting nice and warm, while others remain as cold as ice. In most cases, this phenomenon is caused by unequal static pressure.

You see, there is a finite limit to the amount of hot air a furnace can generate in any given time span. And because some rooms happen to be closer to the furnace than others, these rooms will receive a lion's share of the heat unless the ductwork is modified correctly--a process known as downsizing. In other words, the farther a vent is from the furnace, the smaller the ductwork leading to it should be.   

Never assume that uneven heating problems will go away simply by installing a new furnace. Unless changes are made to the ductwork itself, you may find yourself plagued just the same either way. For that reason, it is vital to address this issue with your contractor before the installation process begins.