You can have too little insulation. There is certainly the wrong type of insulation. Many of the above photos show a spay foam insulation. The foam insulation pictured above show what’s called “open cell” insulation. 

All insulation has an R-value assigned to it. R stand for resistance. It measures how easily heat can move through the material. The higher the R value the better. Open cell insulation has an R-value of 3.8 per inch. At maximum the site above had about R20 – which is seriously under insulated. The cellulose insulation has an R-value of 3.2-3.8 per inch. 

If this foam had been “closed cell” insulation the denser composition would yield twice the R-value, and this customer’s new heat pump may have performed adequately in the cool autumn months.

However, in the dead of winter, or the high heat of summer, R40 will only be adequate; it will not be kind on your energy bills. 

The wrong type of insulation

Virtually all insulation types are “good” at what they do. There was a period in the 90’s when fiberglass insulation was manufactured incorrectly, but now-a-days that’s not an issue. The real issue is application: you need to