Tuesday, 13 May 2014

Primaloft Information to start off a series of Reviews

Okay, so I have already reviewed the Keela Belay jacket. But I thought this information might be useful to show the efficiency of different types and weights of Primaloft insulation used in the jackets I already have and will review.


Thermal insulation has a value, a CLO value where one CLO unit represents 0.155m2K/W. This is based on the difference between a persons skin temperature and the outside temperature of the material. So a higher value represents a higher difference between your skin temperature and the outer material temperature, a good thing if it is cold. This means a higher CLO value is better.


So to compare Primaloft One and Primaloft Eco I have put together the following chart.


Primaloft One
Thermal Efficiency
*CLO/G/M2
*CLO/G/M2

DRY
WET
Percentage of Dry Efficiency Once Wet
0.027*
0.026*
96.30%

Primaloft Eco
Thermal Efficiency
*CLO/G/M2
*CLO/G/M2

DRY
WET
Percentage of Dry Efficiency Once Wet
0.02*
0.017*
85.00%


The values may not mean anything to you, but the comparison of the two different types of Primaloft possibly will. Especially the loss of efficiency when wet. It's important to note that Primaloft One losses less of it's ability to insulate when wet. Primaloft Eco losses three times more of it's efficiency once wet than Primaloft One.


The following chart shows how much more Primalft One is than Primaloft Eco.


Efficiency of One over ECO
DRY
WET
1.35
1.53


So going by the figures Primaloft One, gram for gram, is 1.35 times more efficient than Primaloft Eco when dry. When wet, Primaloft One is 1.53 times more efficient than Primaloft Eco. (All information sourced from the Primaloft website).

So the next series of charts take into account four jackets, two to be reviewed Rab Photon and Montane Prism), the Keela Belay jacket that has already been reviewed and the Rab Generator Alpine as a comparison.

  
Montane Prism
Total weight of insulation
Body
Hood and Sleeves
40 gm2
40 gm2
Efficiency of Insulation (gm2xThermal Efficiency)
Efficiency of Insulation (gm2xThermal Efficiency)
DRY
DRY
0.8
0.8
WET
WET
0.68
0.68


Rab Photon
Total weight of insulation
Body
Hood and Sleeves
133 gm2
100 gm2
Efficiency of Insulation (gm2xThermal Efficiency)
Efficiency of Insulation (gm2xThermal Efficiency)
DRY
DRY
2.66
2
WET
WET
2.261
1.7


Keela Belay
Total weight of insulation
Body
Hood and Sleeves
133 gm2
133 gm2
Efficiency of Insulation (gm2xThermal Efficiency)
Efficiency of Insulation (gm2xThermal Efficiency)
DRY
DRY
3.591
3.591
WET
WET
3.458
3.458
http://www.forgottentracks.blogspot.co.uk/2014/01/keela-belay-jacket-review.html

Rab Generator Alpine
Total weight of insulation
Body
Hood and Sleeves
100 gm2
60 gm2
Efficiency of Insulation (gm2xThermal Efficiency)
Efficiency of Insulation (gm2xThermal Efficiency)
DRY
DRY
2.7
1.62
WET
WET
2.6
1.56



The higher the number in red, the better the efficiency of the insulation provided. So purely from an efficiency value point of view, when dry, the body of the Keela Belay provides the highest insulation, followed by the Generator Alpine, closely by the Photon and the Prism quite away below. This doesn't necessarily show which is the worst, but more usefully, which is better for particular circumstances. This I will cover in my reviews, but you can probably make up your own mind from the figures above.