Heaters over open shop doorways

[SpeckledJim]

mrmr96 said:

Munter said:

mrmr96 said:

Stu R said:

That's not their main purpose, as said it's a barrier from the elements. Retail stores consume a ton of energy, another 10-15kw on for all that benefit isn't much really.

Surely the air stream from the roof hits the floor and then will "splash" with half going outside, and the other half going inside? So any warm air on the inside of the air stream will tend to be returned inside. And likewise cold air on the outside will be driven down by the stream, but then "splash" back outside once the stream hits the floor?

Just to confirm. You are both saying the same thing yes?

I think so. I was trying to work out how they achieve the aim of lowering heating costs. I think they do it by making a "wall" to keep the hot air inside. There will be some wasteage as the jets are heated, but the technique would also be somewhat effective with unheated air. (Albeit that would feel unpleasant as you passed through, but it would keep the shop toasty.)

There is a clever thingummy that uses a vertical wall of moving air to separate the smoking and non smoking areas of bars and restaurants. Supposedly works brilliantly.

[strudel]

Same reason why all my radiators seem to be underneath windows?

[mrmr96]

strudel said:

Same reason why all my radiators seem to be underneath windows?

Maybe, but I think it's more likely that in any given room there's more likely to be "space" there, because you're not going to put a book case there as it would block the light. Hence it's a convenient place for a heater. So goes my reckoning anyway. (Also, because the radiator doesn't have a fan on it, it won't be working on the same principal as these "air curtains".)

[FarmyardPants]

strudel said:

Same reason why all my radiators seem to be underneath windows?

You'll get a convection-induced draft at the window if a hot radiator is opposite a cold window, as the air circulates up at the radiator, across the ceiling, down at the window and along the floor to be heated by the rad again.