Topquilt vs Underquilt temp ratings/variations

**cdshan75** · 02-27-2016, 08:55

I'm relatively new to hammock camping, but a veteran camper, in general. I've been making/acquiring some gear specific to hammock camping over the last couple months. After recently making an underquilt with 7.5oz Apex, which is rated by the manufacturer to 10 degrees (F), do you find that a correspondingly rated topquilt is what best suits your needs? Would any of you recommend that the topquilt be rated for lower temps, rated the same, or for higher temps due to being able to add more covers/layers in the hammock?
Any input is appreciated!

**Donk_67** · 02-27-2016, 11:54

I would aim for temperature rating that covers season you're planning to use it in the most. It's fairly easy to supplement top insulation for the occasional foray into colder climes. In my own situation; I went for a 4 season Greylock UQ (easy to vent when needed) and a TQ rated for 20 degree because that temp covers me in 90% of my hanging situations (less middle of summer and deep winter).

**cdshan75** · 02-27-2016, 19:31

Thanks for your reply, Donk_67. I appreciate your thoughts!

**Rolloff** · 02-28-2016, 00:47

I use a 40/20 insulation kit for 3 season hiking and camping. With med base layers and a fleece hood, I've slept comfortably down to 16 or 17 degrees, with no warmth issues. The 20 UQ works so well, that I use it on the Freebird I sleep in every night at home. easy to vent, until summer months.

While most hammock insulation kits can be vented well, a 0 degree set in warmer temps will be more weight and volume than I'd wish to carry, when it wasn't needed. You probably need to ask yourself, how much of your hiking and camping will actually be in the 0 degree ranges. If it's frequent, being in WI that's probably a no brainer. For me, I'll just wear more clothes to bed, and/or add a CCF pad, to my 40/20 kit, if the bottom falls out of the temp.

**Macca81** · 02-28-2016, 20:38

I don't have temp ratings (I make my own, I just eyeball it) on my gear...
But, I found that with my original UQ I made with summer in mind, I could use my TQ and be comfortable through about 4 months of the year, just needing to vent my TQ on the hottest nights. Winter, forget about it!

My new UQ, I was aiming for something that perhaps on a cold night I could wear an extra jacket and the plan was to probably make another TQ to work with it for winter. As it turns out, the added warmth from the UQ means that in summer I can go with no TQ, in the shoulder seasons I can just vent the TQ and in winter it is perfect.

So, I would say, that if you have a warm enough UQ, the TQ is less important. The UQ does most of the work, meaning you can get away with a lighter TQ.

Note: in Australia, we don't get the pure cold that you do in a lot of the USA. However, in Tasmania we get the cold wind off Antarctica, which produces huge amounts of windchill, so blocking the wind is often much more important than pure insulation. YMMV, HYOH

**cdshan75** · 03-01-2016, 08:21

Originally posted by Macca81.

So, I would say, that if you have a warm enough UQ, the TQ is less important. The UQ does most of the work, meaning you can get away with a lighter TQ.

This pretty much answers my question. Thanks to all for your replies.

**dakotaross** · 03-01-2016, 09:05

Due to convection, I'd say the UQ needs to be rated below expected temps, with a TQ being rated for expected temps or a little higher. Most of your heat loss will be on the back side (UQ) whereas the TQ more easily captures and holds in your warmth as heat rises. I use a zero/20 UQ/TQ combo for winter temps in the 20s, with potential lows in the teens. I also use this setup for cooler 3 season trips where lows are high 30s. I use a Jarbridge and a 50 TQ for 40s and up.

**cdshan75** · 03-01-2016, 13:38

Makes sense. This is what I expect, but I've made no actual personal observations. Thanks, dakotaross!

**Bike-N-Hike** · 03-01-2016, 21:55

Take this with a grain of salt so to speak because I really don't have much cold weather camping experience but I found that my 0dF top quilt seemed to be warmer than my under quilt. I found when I recently tested my gear during a cold couple nights that my 0df +2oz, under quilt started getting cold at minus 15df but the top quilt was not a problem.

Especially during winter camping you have more insulation available to layer under your top quilt which could extending your sleep systems range.

To answer your question I think you could go with a lower rated top quilt providing you have other insulation options. However, I would rather sleep in my Baselayer than be all bundled up in clothes. The best part of the top quilt under quilt system for me is the freedom of sleeping unrestricted and free of layers. I personally would opt for a system that allows me to sleep without layering too much.

**WalksIn2Trees** · 03-02-2016, 00:19

I don't trust the ratings, as I've had equipment that didn't even come close to what it's rating was. I think it's better to go by thickness of insulation. There's a formula you can use where you plug in your expected lowest temp, your "comfort" temp, the heat transmission amount of the insulation... What I did was try a known thickness and low temp combo first to use as my baseline goal, it seems for me, I need an inch of down for every 20°F below comfortable (nude)

I put the formula in a spreadsheet so I could simply adjust the variables and get instant results