installing insulation helps air conditioning efficiencyYou may not think of your insulation too often. It’s in your walls, attic or garage, and does its job just by being there. You don’t need to turn it on and off, change it, charge it, or anything else. In fact, you may never even need to see it. But insulation is one of the most important parts of your house and having the right type of insulation for your home is key to keeping you cool in the summer, warm in the winter, and your electricity bill low.

How Does Insulation Work?

In order to pick the right insulation for your needs, you should ensure that you understand how air travels through your home. It’s easiest to talk about these principles in the context of heat, because either way, these principles are moving warm air, not cool.

First, there’s radiation, which is the simple idea that heat moves through your home as waves. When you turn on a lightbulb and it feels warm, it is radiating heat. Up to thirty percent of the heat generated by your home can come from appliances and lights, so keeping radiation in mind is important.

Second, is the concept of convection. This is the idea that we think of in traditional HVAC systems – hot air tends to rise while cool air falls. So, on a warm summer’s day, head up into your attic and you’ll be standing in a sweat lodge, whereas your basement remains nice and cool.

The third principle is conduction, which just how heat moves through a substance. So, pop a pan onto your stove and turn on the burner. That’s conduction.

All three of these principles are working in concert within your home simultaneously. Without insulation, heat (and cool air) would move through your home and directly through to the outside. Insulation keeps the heat loss factor (the speed with which your home “exhales” air) more constant, both in the summer and winter.

What Type of Insulation Do I Need?

Well, first things first – if you’re thinking about adding, removing, or changing your current insulation, it is best to consult with a licensed HVAC professional. Insulation is often made from fiberglass and other harmful materials and your local HVAC pro knows how to handle them and, most importantly, can point you in the right direction on type.

The keyword to remember, however, is R-value, which stands for how well a material resists air flow. The higher the value, the better your insulation is. Certain portions of your home, and the location of that home, need different types of insulation. The insulation in your attic should have a higher value than your interior walls (if they have any at all). If you’re in Northern California, where the weather can get cold, a higher R-value, like R-19, is better because it resists air flow more. By contrast, San Diego remains relatively temperate most of the year, so a lower R-value insulation is acceptable.

Types of Insulation

There are also lots of different materials that you can use for insulation, with varying different uses:

  1. Fiberglass batt: The standard pink stuff you see in your big box home improvement store. Fiberglass is fire resistant and generally cheaper than other insulation types. It can cause irritation, so when installing, be sure that you wear protective gear. Additionally, it isn’t the most environmentally friendly substance.
  2. Cellulose: Made from recycled newspaper, cellulose is similar to fiberglass in that it helps keep the airflow in your home down simply by layering of fibers within the insulation. It is more expensive than fiberglass, but is more environmentally responsible and, in many instances, can provide a much higher R-value.
  3. Spray foam: Becoming more popular in home building, spray foam is applied as a liquid and then expands to fill cracks and crevices. The best place for spray foam is around windows and in between studs in your attic. It is expensive, but never requires replacement.

Learn more about your home insulation options »

Whether you’re building a new home or rehabbing your current one, be sure you choose the right insulation for your environment and application.