A horizontal cylinder may well be the solution where space is at a premium. Particularly useful in confined loft spaces these cylinders are configured horizontally and are available either as direct or indirect and can be supplied with support cradles.
Quite different to it's vertical counterpart, a horizontal pattern cylinder is manufactured to operate laying on it's side as it were, incorporating twin domed ends and a heat exchanger (on an indirect model) that feeds from the top to the bottom, rather than into the side. Although still referred to as 'a coil' a horizontal cylinder heat exchanger more closely resembles a five-bar-gate - putting the heat as low down in the cylinder as possible.