I'm here! Haven't buried myself in the snow or anything -- we don't have any. I'm beginning to forget what snow looked like. Although that's not altogether a bad thing from my point of view...
H-coils are quite good. I mean, it's hard to argue with the performance of modern 808s, right? Kanger started this whole H-coil thing for their 808s and their performance is surprisingly excellent on such a small device. So yeah, they do work very well for the most part. Especially on certain bottom feeders. (Ones without the needle sticking up into the carto.) They work like atomizers that way since the juice hits the coil first.
Where they can potentially fall down though is at higher voltages with thicker juices. H-coils don't work the same way V-coils to. V-coils are arranged in such a way that the coil is vertical in the center of the carto and are wrapped in a thin glass fiber "sock". The juice from the filler soaks the sock and the coil vaporizes the liquid from the sock. The advantage here is that the sock is surrounded 360° by juice-bearing filler, so as you vape, juice gets replenished quickly from all directions, even at higher voltages, because the design utilizes the entire outer surface area of the coil to vaporize liquid.
H-coils on the other hand sit horizontally at the bottom of the carto (duh). They're covered either by a kind of cup with a hole in the center and notches at either side, or by splitting the center tube up the middle so it creates a pair of "legs" that straddle the coil and keep it from touching the filler. Instead of having the juice fed to the coil by way of a sock, it has a wick running through the coil like a more conventional atomizer. The juice feeds the wick, the wick feeds the coil.
This arrangement works well, especially when the juice gets low because the juice will settle to the bottom anyway which allows the wick to soak up more of the juice. However, the wick is only the diameter of the
inner surface of the coil rather than the outer surface like the sock arrangement of V-coils, thus not as much juice can be delivered to the coil at once. This means that at higher voltages, or during chain vaping -- or both -- there's a higher chance you'll start getting dry hits because the juice can't wick to the coil as fast or in as much quantity as with a V-coil and sock arrangement. On the other hand, H-coils do tend to give a warmer vape at the same voltage than a V-coil. I'm not sure why though, given that the coil is technically a little further away, but it may be due to the horizontal orientation of the coil allowing more of its surface area to radiate heat upwards to your mouth than a vertical coil does, which would radiate it mostly outwards into the filler.
So, pluses and minuses for both V and H-coils, really. They each have their function that fills a particular role, I think. Given my druthers I tend to stick with Boges or tanks.
