I always wondered if leaving light bulbs turned on in the house in
winter produces the same amount of heat (per wattage) as an electric
heater of the same wattage.
For example, I know that a 500 watt heater and five 100 watt light
bulbs will both consume 500 watts.
However, will five 100 watt bulbs produce as much heat BTUs as a 500
watt electric space heater?
Anyone know?
On Thu, 27 Jan 2011 05:21:13 -0600, The Daring Dufas
Yes, and not only that, I'm pretty sure the remaining 10% is turned
into heat as soon as it stops being light.
After all, what else could happen to it?
And it stops being light quickly, or a white room with white furniture
would still be lit after you turn off the lights.
re: "And the other 10%, unless it goes out the window, is also
returned as heat."
True, but is it "efficient" heat?
By that I mean this...
My heat vents are at floor level. None of my lights are.
Most of my lights are not only above eye level, but also light up a
large portion of the ceiling.
All that heat up near/at the ceiling isn't quite as "efficient" as the
heat coming from my registers unless it's gets circulated back down to
people level.
If it all starts at the ceiling and stays there, it's wasted to a
certain extent.
On Thu, 27 Jan 2011 13:04:52 -0800 (PST), DerbyDad03
Most (or at leat a fair fraction) of the heat you get from light
bulbs is RADIANT heat - meaning it heats the object, not the air - so
high lights pointing down heat you and the floor - which heats the
air.
Forced air heating works a bit differently - so the outlets are floor
level, and the hot air rizes.
On Thu, 27 Jan 2011 18:02:25 -0500, snipped-for-privacy@snyder.on.ca wrote:
In that case, I think I'll just install all my lights on the floor.
They would be a lot easier to install too. Just cut a whole in the
floor, mount the box from the basement and wire it right to the
breaker box.
I wonder if the code would require some sort of shield around the bulb
for when people trip over them?
This could become a new fad. Think about this. People are boring.
They have always put lights on the ceiling, except for a few on walls.
That's very boring. Do something unique and different, install lights
on the floor.
On Jan 27, 6:02 pm, snipped-for-privacy@snyder.on.ca wrote:
The majority of my "high lights" point up, not down.
The ones that point down are mostly CFL's, so they don't qualify of as
"heat balls".
Most of the ones that point up have 2 150W 3-way heat balls, the
others have bug-frying tungsten halogen lamps.
On Fri, 28 Jan 2011 18:49:09 -0800 (PST), DerbyDad03
Yesh, but the light they emit is still light. Which turns into heat.
Evenly on the walls and furniture and people, except when they are in
the shadows.
As to the light on your ceiling, how many floors does your house have?
Using bulbs as heaters is slightly less efficient as some of the energy is
light. OTOH, I've been told that the light eventually turns to heat, but you
probably need a physicist to give a good explanation of that portion.
It makes a lot of sense to use more efficient types of lighting in many
cases, but in winter, that heat is not lost, but a benefit. In summer, you
are paying to remove that heat with an air conditioner so the CFL is better
then. Fortunately, the new CFL are much better light quality compared to
the sickly green of years past.
even so, a heat pump is more efficient at putting out heat per unit
power than electric resistive heating, so it makes more sense to use
more efficient lighting and rely on a heat pump for heat (assuming you
have an all-electric house. If you have a furnace, the cost/benefit
analysis depends on the cost per BTU of the furnace and electric
resistive heating. I would suspect that in most if not all cases the
furnace would be the better bet.)
Now heat pumps do have drawbacks in cold weather, unless you have a
ground loop system which most people do not...
nate
It's good you raise this. I hadn't thought about it, but I guess they
would be more efficient because they're not making heat entirely out
of electricity, they're pumping the heat in from outside, where even
when it's cold out (by human standards), the air has heat in it.
(If it didn't have heat, the oxygen, nitrogen, and other gases would
all be solids, which would make walking out of the house impossible
without a hammer and chisel. On a warm day maybe they would all be
liquids, so that when you opened your front door, liquid nitrogen and
liquid oxygen etc would start to fill your house. This might work out
okay if you wore insulated hipboots, and I guess when everything dried
most of it woudln't be damaged like water does, but you couldn't leave
fruit or vegetables near the floor.)
Intuitively, there is no heat to be got from cold outside air, but I
guess there is.
(For some reason they say that heat pumps are marginally a good idea
in Baltimore, and not a good idea where it's much colder, but that's
another topic.)
Intuitively, after removing 20" of snow from my driveway this morning you
are correct. Anything above absolute zero has heat. The trick is to
extract it at reasonable cost. Geothermal systems rely on the heat in the
earth and that is often below the temperature we want in the house.
On Thu, 27 Jan 2011 10:39:24 -0500, "Ed Pawlowski"
Really! Until just now I had an image of boiling or almost boiling
lava, or at least really hot stuff like the red center in the drawing
in my 7th grade science book.
It's going to take a while for this to sink in.
Is it at least warmer than the cold air outside? (I guess so or the
pipes would freeze, the frost line would be much lower.) How deep do
you have to go to get 50 degrees F on a cold day?
I've been thinking radiant floor. Pump heat during the day and use it
at night when it is usually 10 or 20 degrees colder. Wouldn't work so
well in overcast weather, but in climates with sunny days storing the
nights heat could be a good deal.
Jeff
My mother rented a house that had that, in Pennsylvania. The owner
or the previous tenant didn't like it, so while my mother was there
the owner replaced it with electric baseboard heat.
Nothing else was economical to install because they'd have to run air
ducts or pipes, and take a lot of space in a 1-story house with no
basement for the furnace.
(I think this happened before I visited so I never experienced it
myself.)
Far from unheard of, hydronic radiant heatis quite common in many
areas, particularly in higher end homes.
And talking about primitive, untill a decade or two ago, central heat
in Britain was a "luxury"
Many people don't understand that a heat pump doesn't produce heat, it
moves heat from one source to another. I wonder if anyone has tried an
underground heat storage pit like the ice storage pits some facilities
have to store cold during the winter and use it for cooling air during
the summer months? I wonder if an inexpensive phase change heat storage
material could be used for both heat and cold storage? Hummmmm, now I
must scratch both ends in order to contemplate the concept. :-)
TDD
HomeOwnersHub.com is a website for homeowners and building and maintenance pros. It is not affiliated with any of the manufacturers or service providers discussed here.
All logos and trade names are the property of their respective owners.