Since the installation is in an unconditioned attic space i went up and looked at the duct install.
Attic ductwork r value.
The effective r value of a buried duct installation depends on the size of the ducts the r value of the duct insulation and the depth of the loose fill insulation.
If you measure air temp at evaporator coil and supply air temp from vents the air is picking up very.
Recently i had another hvac company come out and put in a new bathroom vent and they told me they believed the duct work was full of water.
Insulation levels are specified by r value.
R value is a measure of insulation s ability to resist heat flow.
And that means it s time to deal with duct insulation in a more meaningful way than just increasing the required r value to 8 for ducts in attics.
Table 1 shows effective r values for 8 inch round ducts at three attic insulation levels and three duct insulation levels r 4 2 r 6 and r 8.
I called out the original hvac company and they took a look and said they saw no water.
R value is a measure of insulation s ability to resist heat traveling through it.
So i notice the ductboard is oc s quietr with an r value of 4 3.
The attic ductwork is flex duct work.
Insulation level are specified by r value.
Recommended home insulation r values.
For example if you have a type of insulation that has an r value of r 5 per inch of thickness you will need a depth of 6 inches of this insulation installed in your attic to reach r 30 if you live in zones 2 or 3.
I check on the oc website and find that the 4 3 is the lowest r value they make.
Allison bailes of decatur georgia is a speaker writer building science consultant and the author of the energy vanguard blog.
When insulating ducts understanding the meaning and impact of r values and insulation thicknesses is essential to getting the most efficient affordable outcome on your heating installation project the ratings provide a guide for homeowners that determines the effectiveness of the insulation making it easier to choose the right insulation for your home.
It was new when the ac was put in 7 years ago.
The higher the r value the better the thermal performance of the insulation.
This is why the r values are so different.
The recommended level for most attics is to insulate to r 38 or about 10 to 14 inches depending on insulation type.
My attic gets hot and so i was wondering how much cool air i was losing to the heat of the attic.
Return ducts ductwork that brings expended air back to the hvac system to be filtered reconditioned and redistributed require insulation with an r value of 3 5 for exterior ducts and ducts in a ventilated attic or unvented attic above an insulated ceiling.
The higher the r value the better the thermal performance of the insulation.
