Down and Insulated Jackets

PrimaLoft ThermoPlume+ Insulation | Review

The Rab Cirrus Ultra Hoody is the first product to feature PrimaLoft’s new ThermoPlume+, a synthetic fill that brings an impressive warmth-to-weight ratio to the table, and more

I first came across the new Rab Cirrus Ultra Hoody when it was being exhibited as part of the OIA Awards and, at the time, I couldn’t work out whether it was down filled or synthetic. Normally a good pinch will reveal what’s inside, but in that instance, a pinch was inconclusive, and that’s testament to just how close to mimicking down fill that PrimaLoft have now managed to get with their new Thermoplume + technology.

ThermoPlume, as we’ve known it for the last few years, has been made up of small, silky synthetic fibres that cluster together in little plumes in a way similar to goose or duck down. This structure helps it replicate the softness, loft, and thermal efficiency of natural down, while having the added benefit that it doesn’t loose all of its insulating properties when it gets wet.

The new PrimaLoft ThermoPlume+ structure, with the addition of little half moon shaped clusters that add extra warmth with no extra weight.

Now, PrimaLoft have updated their technology, releasing a new iteration called ThermoPlume+ which the company says is able to offer the same loft as before, but with 20% less material. To achieve this, they’ve changed the structure of the fill by adding little balls of fibres into the mix. These, combined with the plumes of PrimaLoft fibres, create a scaffolding effect that resists clumping while providing a down-like warmth and feel.

The ThermoPlume+ fill, along with the majority of insulating products that PrimaLoft produce, is made from 100% post-consumer recycled materials – mainly recycled bottles.

Performance

In the Rab Cirrus Ultra Hoody the ThermoPlume+ fill also combines with Rab’s TILT technology, a reflective lining that enhances warmth by reflecting body heat back toward the user, improving thermal efficiency without adding extra weight or bulk. Interestingly, you can actually just about see the TILT’s shiny dots through the translucent liner material.

I’ve been using the Cirrus Ultra Hoody synthetic insulated jacket this autumn, most notably on a cold few days in the Lake District, and for daily dog walks through some very miserable wet and cold weather. Weighing 548g (men’s size medium) I’d call it a mid to heavy-weight insulator; it’s not the kind of jacket that you’re going to scale Everest in but it’s the right kind of insulation for winter hiking, climbing and alpine pursuits. I’d say it’s a touch on the heavy side as a layer to carry in a backpack during summer long distance walks, but it should serve well as something you can wear all day on those very chilly days out in winter.

I’ve found it repels light rain very well and although it does eventually wet out in heavy rain, it still manages to loft and still provide warmth. The durability is impressive too; it’s a jacket that seems to have relatively good abrasion resistance to it – for a puffer jacket anyway. I can see it lasting well.

Fit

I’m 5 foot 10, I have an average build and I tried this in a medium, which is my usual size. I found it fitted nicely and paired well with a thick baselayer top. I could wear it over a thick fleece though it did feel a little tight around the armpits. The hem is cut to come down to just below the top of your trouser pockets and then the backside drops slightly. It feels well articulated, with the hem not lifting at all when reaching up high.

The Cirrus Ultra Hoody is also available in a women’s version too.

Features

Rab have always had a strong reputation for designing clothing with the right technical details for mountain use and nothing’s changed here. The hood, for instance, is well insulated, it fits comfortably underneath a helmet and it has a long peak with a mouldable wire inside it.

The two-way main zip makes it harness compatible and I found you can still comfortably use the handwarmer pockets when wearing a harness of a backpack with a hipbelt. The main pocket on the chest is the right size for a smartphone or a handheld GPS and you can stash the whole jacket away in the left handwarmer pocket. All bundled up, it’s about the size of a loaf of bread.

One other touch I really like was the inclusion of a very soft and comfortable microfibre fleece around the chin. There’s also a beard guard at the top of the zip.

Verdict

This is the first time I’ve used a jacket with PrimaLoft’s ThermoPlume+ technology and I’ve liked what I’ve seen. It really does feel and perform a lot like down but with the added benefit of being more water resistant. I also have got the impression that the insulation is quite hardy. The fibres seem to be able to quickly retain their loftiness even after the jacket has spent most of the day stuffed away into a backpack.

A closer look at the two types of clusters used in the new PrimaLoft ThermoPlume+.

Rab deserves credit for not only using a 100% recycled fill but also using 100% recycled materials for the liner and shell fabrics. As is the case with all products on the Rab website, you can see exactly what materials are used in the jacket, whether any PFCs are present (they aren’t) and where the garment was manufactured. This is part of their impressive Material Facts scheme which aims to provide full transparency for consumers.

No doubt PrimaLoft’s ThermoPlume+ will be rolling out in loads of other products from a range of brands going forward, so keep your eyes peeled for the label when you’re shopping around.