March 21, 2012. Cellulose Insulation compared to Prodex Total Insulation
Cellulose Insulation (also referred to as Blown in Insulation) is composed of loose-fill shredded and treated newspaper. Its R-value per inch is approximately 3.5.
Moisture absorption in cellulose insulation can make it heavier, causing it to become compacted and lose its insolative value. It is prone to create too much dust that is blown into the house through inadequate seals around fixtures or minute holes - This can be a health issue especially in a carpet-less home where dust stays airborne longer. Prodex is unaffected by moisture and is composed of 100 percent virgin recyclable materials.
Problems can occur relating to the distribution of the cellulose. It can be difficult to maintain an even distribution of the cellulose. The insulation slides down from the center peak of the house towards the edges. You're left with little or no insulation along the middle of the ceiling. A failure to insulate 5% of an attic results in a 52% heat loss. Not vary air-tight, air can flow through the insulation especially when coverage is light. Installing Prodex Total insulation over the studs creates and air, vapor and radiant barrier.
The actual R value of cellulose insulation may be lower by as much as 20% due to wood framing. Wood framing that holds the insulation in place reduces its effectiveness. Wood conducts heat faster than insulation, a phenomenon known as "thermal bridging." Cellulose insulation in a 2-by-6 wall can be rated R-19 by its manufacturer, but the conductive effects of the wood framing would reduce this to R-15. Installing Prodex Total insulation R 16 over the studs rather than blowing in cellulose between the studs solves the bridging dilemma.
You also need to be concerned with shorting by your contractor. Shorting means that all the material needed to achieve a given R-value is not installed. For example, the average settled depth of cellulose is 5-1/2 inches for an attic requiring R-30. It should be at least 8 inches. This is a case of an attic being shorted 31%. The average customer only gets an R-value of 19 on an R-30 request. Prodex is an easy DIY installation project. No need to pay for a contractor or be concerned with shorting.
Cellulose insulation will not prevent radiant heat transfer (The primary source of heat-flow in and out of your structure). Without a radiant barrier, when the roof get hot, it radiates solar-generated heat down into the cellulose insulation on the attic floor. Cellulose insulation primarily reduces heat transfer by trapping the warm air. It has a high radiant heat transfer rate; therefore, it's a good radiator of this absorbed and retained heat. As the surface of the insulation radiate infrared rays in all directions, the heat trapped in the cellulose insulation during the day will radiate down through the ceiling into the air-conditioned living space at night. This means you'll need to run the air-conditioning system at night and thereby waste more money. Prodex Total Insulation blocks 97% of radiant heat from reaching the insulation and the air-conditioned living space below. Prodex Reviews