UKC

I'm looking for recommendations for a synthetic sleeping bag. It needs to be warm, but compressible enough to be practical for a combined climbing & camping trip.

My current sleeping bag is a Mountain Equipment Starlight IV. It's supposed to be comfortable at +5 to -18 deg C.  I've recently used it in temperatures that have probably been between 5 & 10 deg C, and I've been cold despite thermals, socks and hat (and a very good sleeping mat). It's also very bulky: it fills half of my climbing rucksack even when squashed down as much as possible.

I hate being cold when I'm trying to sleep (vs OH who hates being hot).

I don't want a down sleeping bag: I'm allergic to down and whilst I can wear down jackets, after a night in a down sleeping bag I wake up with puffy eyes and other allergic symptoms. I was given a wonderful down sleeping bag as a present for significant birthday a few years ago, but had to get rid of it. I realise this means there will be compromises to be made with regard to size & weight.

I'm a 5'6" (1.68m) tall woman.

Thanks in advance for helpful suggestions & comparisons.

In reply to Becky E:

I'd also be interested in folk's suggestions. I'm not allergic to down but I'm always concerned about down bags getting damp/wet. I've had a few synthetic bags recently that haven't lived up to expectations in warmth claims.

In reply to Becky E: every synthetic bag I have had has lost its insulation properties after a relatively short time. I understand this is because coating applied to the man made fibres deteriorate and the fibres lose their loft. This is accelerated by compressing them. Have you tried a good quality silk or similar liner for your down bag?

In reply to Lankyman:

I use my down bag for sea kayak camping, i’ve never had a problem with it getting damp but I do stuff it into a dry bag to protect it

In reply to kevin stephens:

It's not so much keeping it dry when backpacking it's more condensation from contacting the inner tent sides in my experience.

In reply to Becky E:

Unfortunately warm, compressible = down.  Not many ifs or buts sadly.

The hollofil-type fibres crush so lose loft fairly fast.

My son has similar allergies and takes systemic anti-histamines for 2-3 days prior, and in use; problem solved

In reply to Becky E:

Used a big Agnes anthracite for couple weeks and it had mega loft and cosy to temps below 0 in the states. Can't comment on it's longevity past that and we were car camping but did think it was well priced for specs, def bulkier than down but wasn't excessive size. 

In reply to Lankyman:

A bit of water repellent spay on the inner tent may help with the condensation. It has worked well on my lightweight tent.

In reply to Lankyman:

What tent do you use? I don’t tend to get condensation in my tent

In reply to Becky E:

Have a look at Snugpak options.... I've been happy with my 2 over the last 25 years

In reply to kevin stephens:

It's an old Saunders. It's a combination of adverse conditions and the lack of space making contact with the inner inevitable. My other tent is a cavernous Macpac Olympus and even there keeping a bag dry wasn't always possible. I recall pitching on bare earth once (unavoidable) and a heavy squall of rain caused water (and mud!) to bounce up between the inner and outer, wetting the inner walls. I could buy a new tent ... ?

In reply to buxtoncoffeelover:

I had a Snugpak which went round the world with me for a year and it was excellent. It also did sterling service over many a mountain over a couple of decades. It got so tatty eventually that it had to be euthanased. I shed a tear.

In reply to Lankyman:

I've got a North Face "Cat's Meow" that has always been disappointing in the warmth stakes. Should be a 3-season bag, but unless it's the height of summer, it's pathetic - and I'm generally a warm sleeper.

In reply to Andy Manthorpe:

I hadn't considered that. What spray do you use? My old Spacepacker has a cotton inner.

In reply to buxtoncoffeelover:

Thanks, that's a good idea.

My very first proper sleeping bag was a Snugpak. It lasted nearly 30 years until the airline lost it. It did everything from Omani desert camping to a (rather chilly) night at the Roaches in November.  I miss that sleeping bag. It was anything but compact though. But 1980s technology. 

In reply to Becky E:

My new one (5 years old) is lighter & packs smaller than my old favourite, without noticeable loss of performance. Kept uncompressed at home, it retains its loft for some time

In reply to Lankyman:

If I recall correctly I used Grangers Fabsil Gold, which I had used on the flysheet.

In reply to Becky E:

I'm a terrible one for sleeping cold (I use a -25c rated sleeping bag once the temp drops below about +5c!!! But I can use down.

I won't make any suggestions on sleeping bags but it is worth thinking about other ways to keep warm at night. My two go-tos are.

The type and quality sleeping mat. A bit of closed cell mat under a self-inflater can make a big difference, or a self-inflater with a very high r-rating.

Using a Sigg bottle as a hot water bottle (stuff in a sock to avoid danger of burns)

In reply to LastBoyScout:

I wonder what year they are. I have some TNF Dark Star bags from around 2014/16, rated at -40C and -29C respectively. I've camped in temps (outside the tent) down to -33C and always found them really good. The combination of the adjustable neck baffles and a hood that can cover everything except your mouth means they're scary efficient at keeping heat in. They use shingled Climashield which whilst bulky is really warm and resilient. I've never seen any bags on the market that looked nearly as good compared to these. Shame they discontinued them (like all good products). 

In reply to Becky E:

I'm currently looking at this and thinking of synthetic vs down because I'm planning on doing some biviing and it just makes more sense if there's a chance of your bag getting moist. I've been looking at the Rab solar eco 2 versus the 1degree down equivalent and was shocked to see that the synthetic was rated for 2 degrees rather than 1, but was 100g lighter than the down! With the same pack size...

In reply to Becky E:

I agree with WelshKate - use a water bottle.  I was camping on 2nd January on the Mendips when it was -5 outside.  I was in my old 3 season bag which would normally be a bit cold at that temperature.  However  this time i tried using my 1 litre Nalgene water bottle as a hot water bottle, wrapped in a thick woollen sock.  I probably had the water at about 60 degs C, certainly not boiling.

What a revelation!  It warmed my frozen feet and kept them warm all night.  It's taken me 50 years to remember what we used to do as kids 🙂.  Using a water bottle means you can use a slightly thinner bag (although you do need a bit more fuel for your stove).  And you can use the warm water in the morning to speed up your first brew!