Knowledge base
The question usually comes up late, when the generator room is already drawn and someone asks where the radiator goes. Horizontal and vertical remote radiators do the same job with the same kind of finned coil and the same electric fans. What differs is the direction the air takes: up and away from a coil lying flat, or sideways through a coil standing on edge. That one difference changes the footprint, the way the unit reacts to wind and neighbours, where its sound goes and how it is serviced. This guide walks through those points so the layout can be agreed before the pipework is fixed.
Where The Warm Air Goes
A horizontal radiator lays the coil flat on legs, with the fans above it drawing the air through (induced draught) or below it blowing the air in (forced draught). Either way the air comes in from underneath and the sides, and the warm air leaves upward. Warm air rises anyway, so it clears the unit on its own and rarely finds its way back to the inlet.
A vertical radiator stands the coil upright and moves the air horizontally, from one face to the other. The discharge goes out sideways at working height, which is exactly where buildings, walls, containers and the next unit stand. Kept clear, it works as well as a horizontal one. Placed in front of a wall or facing another radiator, it starts to breathe its own warm air, and the engine sees a hotter day than the weather report.
Footprint, Height And The Plot
The horizontal layout needs ground or roof area: the coil surface lies on the plan, and the unit needs free space around and under it for the air to arrive. On open ground and on flat roofs that space is usually there, and several units can stand in a row with the warm air going straight up between them.
The vertical layout turns the coil surface into height. It takes less floor area and fits along a boundary, against a building line, in a narrow yard or beside a container, and it can blow through a louvre or a duct into or out of an enclosure. The price is a taller structure that must be anchored for wind, and a clear zone in front of the discharge face that someone has to keep free over the life of the plant.
Wind, Weather And Sound
Wind treats the two differently. A strong wind across a flat coil disturbs the air a little; a wind blowing straight at the discharge face of a vertical unit pushes against the fans and can turn the warm plume back toward the inlet. The usual answer is to face the discharge away from the prevailing wind, which is easier to decide when the site plan shows north and the wind direction. Rain, snow and leaves fall onto a horizontal coil; a coil standing upright sheds them. Sand and dust are carried by wind, so on desert sites the question is more about which face looks into the wind than about which way the coil lies.
Sound also follows the air. A horizontal unit sends most of its fan noise upward, which suits a site with neighbours at ground level. A vertical unit sends it sideways from the discharge face, so it matters which way that face points: toward an empty field it is no problem, toward an office or a property line it may decide the fan choice.
Access, Service And Several Engines
Fans, motors and the junction box of a vertical unit are at a height a technician can reach from the ground or a short platform, and both coil faces can be inspected and cleaned without climbing onto the unit. On a horizontal unit the fans sit on top or underneath, so service means a walkway, a ladder or a lift, and the area under the coil has to stay open for the air and for cleaning. On multi-engine stations the choice is often made once for the whole site. Horizontal units in rows on a common steel structure, or vertical units in a line along a wall facing open ground, both work well; mixing the two usually means one of them ends up in the other's warm air. Where the plot is large and the duty is large, a V-type radiator is the third option worth considering.
TECS Engineering designs and builds both layouts, with single or LT/HT coils, AC or EC fans and the same materials and corrosion options. A site plan with the space available, north, the wind direction and the nearest neighbours tells us more about the right layout than the engine data sheet does - send both, and the proposal will show the layout that fits.
In Short
- Horizontal: coil lying flat, warm air leaves upward and clears itself
- Vertical: coil standing upright, air leaves sideways at working height
- Horizontal needs plan area; vertical needs height and a free zone in front of the discharge
- Vertical units can blow through louvres or ducts of an enclosure
- Wind direction, neighbours and the sound limit often decide between the two
- Fans of a vertical unit are easier to reach; horizontal units need a walkway or lift
What To Send With An Enquiry
- Engine data sheet, or heat duty, flow and temperatures of each circuit
- Site plan with the space available, north and the prevailing wind
- Ground, roof or platform, and any louvre or duct the air must pass
- Nearby buildings, walls and other radiators
- Sound limit and where it is measured
- Site ambient, altitude, dust or coastal conditions and the fan power supply
Questions We Are Often Asked
What is the difference between a horizontal and a vertical radiator?
The direction of the air. A horizontal radiator has a flat coil and sends the warm air upward; a vertical radiator has an upright coil and sends it sideways. The coil, fans and circuits are of the same kind.
Which one cools better?
Neither, if each is installed correctly. A vertical unit loses performance when its discharge is blocked or blown back by wind, a horizontal unit when the air cannot reach it from below and the sides.
Which layout takes less space?
A vertical radiator takes less floor area because the coil surface stands upright, but it needs height and a clear zone in front of its discharge face.
Can a vertical radiator be placed against a wall?
Its inlet side can face a wall at a sensible distance or a louvre, but the discharge side needs free space or a duct to the outside, otherwise the warm air comes back to the inlet.
Is a horizontal radiator quieter?
It sends more of its fan noise upward, which helps when neighbours are at ground level. Which unit is quieter at a given point depends on the fans and on where that point lies.
Contact Us
Send us the heat duty, the fluid temperatures and flow rates, the ambient conditions and the installation limits. We answer with a design proposal - or write to us on WhatsApp.
