Thermal comfort in winter workshops

[Andrew Troup]

Here's a tip for boatbuilding in cold winter premises, too big to heat.

I mounted a radiant single-bar electric heater (one of the long ones, with a wire-wound element inside a quartz glass tube) vertically on a castering base (one of many around my workshop, often pillaged from clothing shop display stands via second hand dealers, or cannibalised from office chairs...)

NOTE: if doing this, the element must be rewound with oxidised wire, so some turns do not short out to each other, reducing the resistance and causing local overheating (uneven red glow) and burnout. I learned this the hard way ...

Here are two other observations:

A vertical heater is good for providing infra-red heat in the right 'envelope' for a person standing at a bench or machine, and the caster base makes it easy to move to where you're working, if you're doing something relatively static.

I guess you could make one that followed you round like a dalek, if you were of a mind to . Probably not a good idea if working in wood or fibreglass .... While you're at it, equip it with a shop vac, so it can do something useful on its travels. Install hanging electrical plugs everywhere to keep the floor clear, first....

Coming back to reality: A variac is a much better way of modulating the output of that heater than a thermostat: with the latter, you're always either roasting or freezing, particularly in a big, draughty, open space: by the time the air around the thermostat has warmed up, you're toast.

A variac means the heater is always on, but at a suitable energy output, and it's VERY efficient: hardly any energy is wasted.

A transformer is the electrical analog to a gearbox (the former swaps volts for amps, the latter speed for torque), except a transformer is even better, having no moving parts.
A variable transformer (variac) has a couple of moving parts, but nothing in comparison with a variable ratio gearbox, so it appeals to mechanical engineers....

Variacs are 'old school' tech, so you can sometimes pick them up quite reasonably priced, second hand.