Whether you’ve heard it called R-Factor insulation, the R-Value of insulation or insulation R-Value, the rating number it refers to can wind up costing or saving you hundreds of dollars each year. Despite these potential savings, many people still don’t know what it is, why it isn’t the only thing to consider when buying insulation, or if they even have the right type and amount of insulation in their home.

Related: How to Qualify for a Tax Rebate for Insulating Your Home

R-Value insulation. So, what is R-Value? R-Value is short for Resistance-Value. The purpose of insulation is to keep the inside of the home at your desired temperature while using the least amount of energy possible. Resistance-Value is one way of measuring your insulation’s effectiveness.

Insulation performs its duty by preventing heat from passing through it. The insulation is tested in a lab, and then assigned a Resistance-Value number based on how well it slows or stops the movement of heat. The higher the number rating, the more resistance – or heat-stopping power – the insulation has. So, the higher the R-Value of insulation, the better the insulation, right? Not so fast.

Your home isn’t a laboratory. Despite the manufacturer’s best intentions with Resistance-Value, there are a number of other issues to consider. For starters, your home has many elements at play. Wind, rain and snow batter the outside of your house. Your heating and cooling systems rapidly shoot air throughout the inside of your home, and right out of the tiny gaps, voids and cracks you can’t see. Air pressures dip and rise, while humidity levels and temperatures change from morning to noon to night – this whirlwind of ever-changing factors is impossible to replicate in a lab. As such, the thermal performance of your insulation is directly affected by where you live, meaning you need different R-Value insulation depending on your region.

But the real problem with Resistance-Value as a sole indicator of insulation’s effectiveness is that it only measures one of four ways that heat moves in and out of your home. While it does measure conduction, it fails to account for convection, radiation and air infiltration. So in order to thoroughly insulate your home, you need: the proper R-Value to prevent conduction heat loss, a pneumatic application to prevent air infiltration and convection heat loss, and the proper packing density to prevent air infiltration and radiation heat loss. In other words, you don’t only need the right type of insulation, you also need professional insulation installation.

R-Value insulation chart. In order to make sure you have the right insulation for your region, take a look at the R-Value insulation chart in Fig. 1 and determine what zone you live in. The overall Resistance-Value of your home can be changed by installing completely new insulation, or by adding more to existing insulation. Thankfully, you don’t need an R-Value calculator – just the information below. The Environmental Protection Agency’s (EPA) ENERGY STAR ®guidelines1 recommend the following for each zone:

Time to call the experts. There are many other things to take into consideration before choosing insulation. Do you have a single- or multi-level home? How high are your ceilings? Do you have a basement? Slab? Central air? A heat pump? A furnace? Wood frame walls? Crawl spaces? Do you want your insulation to help prevent against cockroaches, termites and other pests?

Do yourself a favor and call Terminix® today to set up your free insulation inspection. Not only will they make sure you have the best Resistance-Value for your attic, but will also provide the professional installation and pest protection that your home deserves. Why wrestle with R-Value and other complicated factors, when the experts at Terminix can make your insulation – and pest – problems melt away?