Thinking of switching to a quilt

The zPacks bags are pretty light. How much weight will you save?

What are you hoping to gain? The ZPacks bags are little more than quilts to begin with. You're not likely to beat them for weight vs temp rating, and for some places that IS considered "3 season".
I would definitely look at a 40-50F quilt for summer, though. A 20F would be unusable for me in warm weather, no matter how much people talk about venting. For that matter, my 50F was more than I needed last week, but I was in Louisiana…

Really no need to switch, the Z packs as mentioned by the other poster is already a quilt for the most part. If you want to switch because the Z packs does not fit right or seem wide enough than go with the Enlightened Equipment because they make various widths including a wide model.

I might be able to save a bit of weight. My existing bag is 19.8 oz. A 20F Revelation regular/wide is 19.1 oz, or 18.2 oz with regular/regular.

The bag I have fits fine. The only thing I am not in love with is the sewn footbox. I've slept a few times with my feet under the footbox because it is too warm inside of it.

More generally, I'm hoping to gain more comfort when temps are warm in the summer (say 40-50 F). Will a quilt with no sewn-in footbox would be comfortable at those temperatures due to increased venting, even if the quilt itself is rated for a much lower temperature like 20F? Or, would I be better off getting, say, a 40F quilt for summer use instead?

I am open to both options, but like the elegance of a "one quilt" solution if that is reasonable. Will a warmer quilt be able to vent enough to keep me happy in the summer, or will I inevitably want a summer-only quilt?

my thoughts, you could certainly go to a quilt and save a little bit of weight OR you could grab a "summer" quilt and save quite a bit of weight AND then, combine the two in the "winter" and have a nice little system to use year round :)

I agree with what Mike M said.

Furthermore, you could likely "push" the use of the summer quilt well into the shoulder season, depending on weather, layering etc.

I use quilts with snaps or double sided velcro rather than a sewn in footbox. I never go without at least a 20F setup, but I can open out the footbox if temps are higher than 50F and be fine even though the quilt itself is warmer than it needs to be.

Plenty of vendors have that option. My Hammock Gear 0 degree has snaps.

Okay, now I am leaning towards getting a summer quilt. If I wanted to be able to layer it over my 3-season bag, would it need to be larger/wider than normal? I am assuming the lighter quilt would go on the outside of the bag in the winter. Would a larger quilt also be better if I want to "push" it in colder temperatures? I am assuming it would allow me to wear some extra insulating layers…

Cameron- yes to both questions. You want the quilt large enough to not degrade the loft of your inner bag, and you're correct you want it large enough for layers if you want to it push it a bit w/ insulating layers.

I'd also not rule out synthetic as an option for a summer bag, for a 40-50 quilt you're not talking a ton of loft and at those lesser lofts syn competes pretty decently. Some would argue that a syn quilt makes a better outer quilt for winter use as that's where a lot of your body vapor ends up.

Mike

Mike,

Thanks for the advice! So how wide does the 40F quilt need to be to layer outside the 20F bag? My bag is 61" in girth, according to the ZPacks website.

The widest MLD spirit quilts are only 52". EE goes up to 64" for extra-wide, or 58" for wide. But presumably since the quilt doesn't go all the way around this should be plenty wide, or so I would think.

I have been leaning towards a synthetic quilt like the MLD spirit or EE prodigy to better deal with moisture, both in the winter and on warm, humid nights in the summer. My concern is that either the quilt will be heavier (almost as heavy as my 20F bag!) if I get a 40 F (or Spirit 38) but that I won't be able to use it often enough if I get a 50 F (or Spirit 48). Does this make sense?

take a cloth measuring tape and go around your fully lofted bag; as you stated you don't need to go all the way around, just enough to tuck it in a little – my guess (only a guess) is that 58" would be plenty

looking at the EE site looks like the syn takes a pretty big jump going from 50 to 40F, down would definitely be tempting at that temp :)

"Does this make sense?"
Well, does it?
You went from wanting a summer quilt to basing your choices on using it for WINTER at just the mention of it. I'd say you need to clarify what you're going to use the quilt for, and buy based on intended use. "What if" is not a reason.

-How often do you actually see yourself doubling these quilts?
-What do you do now when temps are too cold for your 20F? When is it not enough with the puffy jacket and insulated pants or heavy baselayer bottoms that you have for camp at those kind of temps, anyway?
You didn't say anything about needing a warmer quilt for winter before.
-What kind of massive moisture problems do you have that your summer quilt just HAS to be synthetic, and much wider(with the corresponding increases in weight and bulk) so it can go on the outside of the warmer one?
Don't forget, the one on the outside needs to be the one to attach to the pad, too, to keep drafts out-more options and/or accessories you don't need on a summer quilt.

Perhaps I should clarify. I currently don't do any winter camping, but might want to start in the future. So, I think I should prioritize the summer usage, because that's when I'm going to use it most. It would be a nice bonus if the quilt could be used as an overquilt in the winter, though. Especially if I wouldn't need to size up too much – though it seems I might need to get a wider quilt to accommodate things.

As far as summer use is concerned, I do most of my hiking/camping either in the Cascades, or in the White Mountains. I like the idea of a synthetic quilt for coping with the humidity/wetness in these areas. I also like that synthetic is cheaper and can be washed more easily. But, it's a lot heavier. It seems pointless to me to get a 40F synthetic bag if that's gonna be the same weight as my 20F down bag. I don't think a 50F bag will be warm enough, period, in these places.

Which leaves a 40F down quilt as a real contender. It looks like I would save about 6 oz or so in the summer. If I get one wide enough to double as a winter overquilt, the weight penalty is < 1 oz (assuming I go up one size in width, but I have to measure this to be sure).

If it sounds like I am going back and forth on this one, it's because I am! I'm really not sure what to do…

"If it sounds like I am going back and forth on this one, it's because I am! I'm really not sure what to do…"
Honestly, I don't think it's a big deal, or will cost you more than a few ounces, to give your summer quilt that added versatility. I was just verbalizing the questions that I would ask myself in your position because it struck me funny that your intended use seemed to reverse so readily.
A wide 40F does sound like a reasonable choice for you, perhaps with HyperDry or another hydrophobic down that will help it deal with humidity and dry faster while keeping weight and packed size to a minimum.

edit:
btw, I used my 30F and 50F quilts together "just to see" at 4F this January, and they worked great when combined.
The only BUT being that I was using my down parka as a pillow and, based on past experience(and since the temps didn't go subzero as expected, plus I'm like a freaking furnace compared to most), could have left the 50F quilt at home.
It was interesting to test out the concept after reading about it here and fooling with it at home, and something I'll do again if the temps get low enough, because my 30 and 50F quilts combined actually weigh 7oz less than my 800 fill bag that's EN rated at 10F.

I don't think you'd have to size up too much, probably one size, ie "normal" to wide- again measure around the quilt fully lofted so you have a little extra to tuck under

I'd look at the winter setup as a bonus :)