Fiberglass insulation is available in batts, which are large rolls that are pre-cut. This makes fiberglass extremely easy to install, and most homeowners with some sort of home improvement knowledge can install it themselves. This can help reduce installation costs, saving you money. Additionally, fiberglass insulation is extremely lightweight, which not only makes the installation process easier, but also means that it can be installed almost anywhere, as support considerations do not need to be taken into account.
However, fiberglass insulation has a number of drawbacks. It is flammable, which can be a safety hazard in the case of a fire, and does not hold up well to extremely low temperatures. It will not retain heat well below a certain temperature (check your specific brand of insulation to see the recommended temperatures). Finally, fiberglass insulation also does not impede air flow, which means that drafts can still occur even with heavy insulation.
Cellulose insulation tends to be slightly denser than fiberglass insulation (check the specific R-value or insulating value of your insulation: higher numbers are better) which translates into slightly better heat retention. It also means that cellulose insulation is better at reducing the amount of exterior noise that seeps into your home, an important consideration, especially if you live near a major transportation route. Additionally, cellulose insulation performs better in low temperature situations, though again you should check with the brand of insulation to see specific numbers.
However, because cellulose insulation is installed through a blower instead of