When you start your search for a sleep system for your backpacking journey you will read about R-Value on many pads. The R-Value system can be used to help you determine the best choice for the cost in your backpacking purchases. Check out our best current value proposition for R-Value sleeping pad @ 15oz!
The R-Value system was developed to provide a better evaluation criterion for sleeping pads and their quality of insulation provided. This is an amazing system to use when trying to find a quality ultralight backpacking system that also provides quality insulation support while you sleep. Before you make your purchase check the R-Value of each choice to make sure you are choosing the best pad value.
Lets expand on what and why the R-Value system provides and make sure you make the best choice while using the information. This can help you with a better quality rest and a lighter piece of equipment, all possibly at a lesser cost once all priorities are weighed.
While R-Value can help you endure cold nights the rating system itself doesn't correlate directly to temperatures. The R-Value system is intended to tell you how well the pad retains heat and warmth, not how it manages outside temperatures.
This doesn't mean that it is irrelevant but more that one doesn't mean the other, a 3 season sleeping pad R-Value of 2 doesn't mean that if your 3 season temperatures were to be -20 F that it would be the best pad for that trip.
Think of this scale in a similar way to other rating systems. The lower the score the less overall insulation you are provided from the ground. This is why understanding the scale will be vitally important to a quality thru hike or long overnight hike.
The R-Value System is to help provide a better overall guide of product versus product as currently their isn't any viable way to compare all pads with other pads. Since it isn't "required" many manufacturers will provide a value or maybe a temperature only value.
The materials, construction, and design of your sleeping pad will directly impact the R-value. We provide our favorites on our recommended gear page, check it out here.
As an example: Inflatable and uninsulated sleeping pads are designed for summer use and probably have an R-value somewhere between 1.0 and 0.7. These are quite low values which are perfectly fine for summer or warm weather use.
It is good to note that R-values are cumulative, this means you could combine two or more pads together to increase your overall warmth level.
Also, women tend to require a higher R-Value pad due to their lower total body mass than men of the same height. This can be compensated for in most cases by upping the R-Value by 1, this is enough for women and other cold sleepers to get proper comfort.
How Therm-A-Rest Tests R-Value:
We measure every mattress design in our on-site cold chamber, kept at a cool 4C (39F). Inside this thermally-sealed container, a mattress is placed between two metal plates. A section of the bottom plate has been turned into a large sensor and is kept at a steady temperature with a measured electrical current.
A mattress that provides a lot of insulation will help keep the bottom plate warm and, as a result, the sensor will require less electricity (energy) to maintain its temperature. A mattress with less insulation will require more energy.
This measurement–the amount of energy required to maintain the plate’s temperature– plugs into an equation to provide an R-value for each mattress–the less energy required to keep the plate warm, the higher the R-value and vice versa.Thermarest Blog
A backpacking sleep pad R-Value is a measurement of its ability to insulate you from the cold ground and its ability to keep you warm. The higher the R-Value, the more effective it will be in ensuring this warmth.
This means you want to find the best R-Value system rating for the maximum weight you want to use for your sleep system. This may mean compromising on a little more of the insulation value to hit the weight class necessary to ensure your backpack doesn't get too heavy or cumbersome.
When factoring in your backpacking, you will want to make sure your deciding factors of weight, comfort, compressibility, and rigidity during your purchase on a sleeping pad selection.
Something else to consider when looking into your purchase is how you sleep. If you are a side sleeper you may find that you don't receive the full R-Value benefit if you choose an inflatable insulated pad.
This is due to how side sleepers lay as their body isn't in full contact with the surface of the pad. Insulated pads depend on your overall body heat to help warm them up in the first place and due to the lack of contact, this doesn't hit the same overall warmth.
Unfortunately, there are some manufacturers who still don't provide any R-Values with their sleeping pads. Many times they fail to provide adequate information, instead, they provide only their minimum recommended temperatures ranges.
The big issue tied to using a temperature rating is there aren't any standard testing procedures to really determine this information. Some brands, like Nemo or Big Agnes, have both had a very poor consumer track records when it comes to temperature range accuracy.
Due to begin in 2020, all new sleeping pads will have to have their R-value testing completed due to new standards which will be required. This means the manufacturers will have to provide them to meet regulations.
Until that occurs though you are on your own if choosing to purchase from manufacturers which refuse to R-Value their gear and use temperature ratings instead to label their pads.
As you have learned a good R-Value can mean a big difference in a comfortable sleep system. You definitely want to ensure you properly are prepared for cold nights with proper insulation as nothing is mentally fatiguing as poor sleep.
Please share this with your friends and family who camp to make sure they have the right sleeping pad for their needs. If you have anything you think I should add please comment or email and let me know! If you have a quality sleeping pad that you would like others to know about share it below also!