Why are central heating radiators placed under Windows?
If the room is heated at a point opposite the window, this draught across the floor is accelerated by upwards convection created by the heat source. To combat this, central heating radiators are placed under windows. This reverses or neutralises the draught, thus giving a much more even distribution of heat in the room, hopefully without draughts.
What is the purpose of the heat shield on Windows?
This is fairly uncomfortable for the occupants. The reason is because the heat loss occurs mostly in the windows and the fenestration. The idea is that you would like the incoming air to be heated up. Also, it creates an air curtain that prevents more heat from being lost through these exposed areas.
Why is the coldest place in the room under a window?
Because under window is the place where delta-T (the Change in Temperature) is largest in the whole room. The larger is delta-T, more efficient the system is. Window even when closed is still a coldest place, because it is a thinnest wall. Cold air flows downwards, thus under window.
How do you stop a window sill from losing heat?
One way to avoid too much heat loss is to have a window sill that projects well over the radiator and curtains that stop on top of the sill. With this arrangement, the heat is directed out into the room instead of behind the curtain and out through the window.
Should you put heaters under windows?
If you live in an older home which has singled glazed windows, the best place to position your radiator is still under a window. This is because the heat that rises from the radiator will mix with the cold air coming in through the window.
Should a radiator be fitted under a window?
The best place for a radiator is in the coldest part of the room. This used to be under windows. However, in more modern double-glazed homes, there may not be a cold area, so you can put radiators where they won't affect the use of walls.
Does a radiator under a window cause condensation?
This can cause moisture in the air to condense out onto the window. In cold enough conditions, the window will accumulate frost or even layers of ice on the inside surface. The hot air rising off a radiator will have less tendency to deposit moisture onto the window (the glass surface will be somewhat warmer).
Why do they put heating vents under windows?
HVAC air supply vents are under windows to counter cool air coming from the window. Cool air sinks because less active molecules are densely packed. The lighter, less dense, active molecules in warm air spread out and rise. As the warm and cold air mix, room temperatures become more comfortable.
How far below a window should a radiator be?
Aim for a minimum of 100mm (4") between the top of the radiator and the bottom of the sill. More is fine. Less than that and the radiator begins to look a little cramped. If you need extra heat, consider using a deeper model of radiator (more columns) or adding one elsewhere in the room.
How far below a window sill should a radiator be?
If a radiator is to be installed under a window, the height of the radiator depends on the distance between the windowsill and the floor. The lower edge of the radiator should be placed at least 10 cm above the floor and the upper one at least 10 cm below the sill.
How big should a radiator be under a window?
A good rule of thumb is to keep the entire radiator (including valves) to within the width of the window reveal. Allow 100mm either side of the radiator for the valves - so a 1000mm-long radiator becomes 1200mm long including valves.
How to prevent cold drafts from window?
One way to prevent these cold drafts from occurring is to prevent the window glass from chilling down to the dew-point temperature of the room air. Since warm air rises, a base-board heater will typically release it’s heated air spanning the width of the window and more so in typical installations.
Why do heaters go under windows?
Perhaps another reason heaters are placed under windows is because - regardless of the type of heating system used - it is the perfect location to keep them from interfering with furniture, etc. because such won’t normally be placed in front of a heater or a window. Steam heating systems shared the same problem.
Why is the heater the most efficient?
Because that is where it is coldest and the heater is most efficient because of higher temperature difference between the heater and its surroundings. Also, it is where they can make the room the most uniform in temperature because other locations would allow the window location to still be cold in relation to the rest of the room.
Why do windows get cold?
Probably because glass windows unless they are double pane with argon between them are terribly inefficient when it comes to keeping cold drafts out. Not the kind from leaking window seals, the kind that are created when the windows get really cold and the air next to the windows gets cooled down to its dew point, and the window starts to collect moisture.
What causes a draft in a room?
the sinking air causes a draft that pumps/circulates air around the room chilling the air in the process.
How much heat does a window lose?
It’s based on heat loss calculations. Windows lose 4–6 times as much heat as an equivalent area of insulated wall. Heat rises, so under the windows is the most efficient place to replace the lost heat. That also helps keep the room at a uniform temperature.
What does it mean when you sit under a cold window?
If you have ever sat under a cold window you probably have felt the “draft” created by the colder air as it “sinks” down off the face of the glass , and is replaced by the warmer air above the cold glass, cold air interface.
How to avoid heat loss?
One way to avoid too much heat loss is to have a window sill that projects well over the radiator and curtains that stop on top of the sill. With this arrangement, the heat is directed out into the room instead of behind the curtain and out through the window.
Why are radiators placed under windows?
RADIATORS are placed under windows so that the remaining walls are free for bookshelves or whatever. The window-wall is naturally rather limited in practical uses.
Why is my radiator not heating up my sofa?
The other possible reason is that, in most rooms, the space under a window is free from obstruction by furniture; hence the radiator would not be heating up the back of a sofa.
Why is it so difficult to get comfortable in cold weather?
This is why, in cold weather, comfort is more easily achieved using a source of radiant heat, such as a blazing log fire, in conjunction with a degree of air movement. Discomfort is caused by cold surfaces such as the glass in a window. Flat panel radiators, primarily a source of radiant heat, are consequently placed below windows to balance out the cold surface above. This is of course, a consideration during the day when the glass is exposed to admit light. At night the window can be insulated from the room by shutters, blinds or curtains, preferably leaving the radiator exposed. Where the radiator is finned to encourage heating of the air and thus the room by convection the situation does however become more complicated. The warm air rising from the radiator will counteract the tendency for cold downdraughts to form in front of the window but the temperature gradient through the window will be greater and the amount of heat lost therefore also greater.
How to insulated a window at night?
At night the window can be insulated from the room by shutters, blinds or curtains, preferably leaving the radiator exposed . Where the radiator is finned to encourage heating of the air and thus the room by convection the situation does however become more complicated. The warm air rising from the radiator will counteract ...
Do central heating radiators have to be under windows?
To combat this, central heating radiators are placed under windows. This reverses or neutralises the draught, thus giving a much more even distribution of heat in the room, hopefully without draughts. Sadly, windows are a great way to waste heat irrespective of radiator placement.
Why is the human body more sensitive to the temperature of surrounding surfaces than to air temperature?
THE HUMAN body is more sensitive to the temperature of surrounding surfaces than it is to air temperature. We find hot still air 'stuffy'. This is why, in cold weather, comfort is more easily achieved using a source of radiant heat, such as a blazing log fire, in conjunction with a degree of air movement. Discomfort is caused by cold surfaces such ...
How does heating up windows help a home?from quora.com
That is done for heating purposes. Most of the heat is lost through windows and windows radiate the “cold” onto you making it feel drafty and uncomfortable. By heating up the windows the home will feel more comfortable. This is much more pronounced in older homes and single pane windows. It is largely unnecessary in well insulated homes but people have gotten used to it and the practice continues. There were some studies done to determine the. Best register location for the most comfort. Floor, ceiling and high sidewall all performed equally as well with low sidewall being the worst due to see
Why do windows feel colder?from theguardian.com
IN ANY heated room, the glass of the windows, particularly of single-glazed windows, will feel colder to the touch than the walls, since the glass is a better conductor (and therefore, loser) of heat. The air in the immediate vicinity of the window is cooled, and since it it now heavier, convects or sinks to the floor, from where it proceeds to cross the floor as a chill draught. If the room is heated at a point opposite the window, this draught across the floor is accelerated by upwards convection created by the heat source. To combat this, central heating radiators are placed under windows. This reverses or neutralises the draught, thus giving a much more even distribution of heat in the room, hopefully without draughts. Sadly, windows are a great way to waste heat irrespective of radiator placement. Thick curtains are a great aid to fuel economy, but remember to tuck them in behind the radiator!
Why do you heat up windows?from quora.com
That is done for heating purposes. Most of the heat is lost through windows and windows radiate the “cold” onto you making it feel drafty and uncomfortable. By heating up the windows the home will feel more comfortable. This is much more pronounced in older homes and single pane windows. It is largely unnecessary in well insulated homes but people have gotten used to it and the practice continues. There were some studies done to determine the. Best register location for the most comfort. Floor, ceiling and high sidewall all performed equally as well with low sidewall being the worst due to seeming drafty and furniture blocking air flow.
How many cubic feet of air does a 5000 BTU window unit cool?from quora.com
For example: You have a 5000 BTU window unit which is capable of cooling roughly 1100 cubic feet of air contained in an insulated structure. That’s a room 10′x15′ with 7′ ceiling height. The same size room with an 8′ wall height and vaulted ceiling increases the volume of air to 1500 cubic feet, thus demanding the need for a 6500 BTU capacity air conditioner. All cooling and heating calculations must be done using cubic feet of air and take into considerati
How does heat affect windows?from quora.com
Most of the heat is lost through windows and windows radiate the “cold” onto you making it feel drafty and uncomfortable. By heating up the windows the home will feel more comfortable. This is much more pronounced in older homes and single pane windows.
Why are heating vents placed in front of windows?from quora.com
Why are heating vents so often placed in front of windows? Supply vents are placed at the furthest extremes of the room so that the air that comes out of them is drawn back through the entire room. They are generally placed in the middle of the wall which is usually location of windows. Also, the windows are the source of the greatest amount ...
Why put a radiator in the coldest part of the room?from physics.stackexchange.com
Therefore it makes sense to put it in the coldest part of the room, not only due to efficiency reasons, but due to the fact that if it gets toohot you can easily open the window and let out some of the excess heat.
Why are radiators under windows?
In the past, radiators have often been located under the window in a room because this is the coldest area in the room. Historically, older windows would be single glazed, and this type of window used to let a lot of cold air into the room. This is one of the reasons the radiator was placed in this location as it would then help counteract ...
Do radiators come in different sizes?
In addition to placement, radiators today come in a wide range of sizes and shapes and these styles of radiator can be used more creatively in the home. Try our range of compact radiators for example.
Why put a radiator in the coldest part of the room?
Therefore it makes sense to put it in the coldest part of the room, not only due to efficiency reasons, but due to the fact that if it gets toohot you can easily open the window and let out some of the excess heat.
How to heat a room with cold floor?
So if someone want well heated room with very cold floor .. do it, put radiator to opposite side .
How to heat air before double glazing?
Before double glazing there would be a draft from the windows so the idea was to heat this incoming air by having a radiator immediately below the window
Why does the cold push the hot air inside the room?
As the hot air goes up and the cold air goes down, the radiator is located where there is a better circulation, i.e. even though the window is double glazed, there will always be cold air entering the division by the material itself. So the cold will push the hot air inside the room.
Why is my window glass cold?
If you have a window without radiator and outside is really cold, the window glass would be cold as well. This will lower temperature of the air around the window and this air will flow immediately down ( physics).
How to optimize heat uniformity?
To optimize the room for maximum heat uniformity, move the heat sources near the windows.
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