Fluorescent Bulbs

[Jeremiahwd]

I need to find out what the actual heat output for T8 fluorescent
bulbs is. I know that internally they create a lot of heat most of
which is converted to visible light by the phosphorus coating on the
inside; but how much heat is finally given off thermally that has to
be removed by an A/C system. Also how about the ballasts? Do
magnetic ones give off more heat than electronic and how much more in
general? If anyone could provide some direction I would greatly
appreciate it.

Jeremiahwd

 

[Don Klipstein]

In article <e274b5da.0406230925.c283473@posting.google.com>, Jeremiahwd wrote:

I need to find out what the actual heat output for T8 fluorescent
bulbs is. I know that internally they create a lot of heat most of
which is converted to visible light by the phosphorus coating on the
inside; but how much heat is finally given off thermally that has to
be removed by an A/C system. Also how about the ballasts? Do
magnetic ones give off more heat than electronic and how much more in
general? If anyone could provide some direction I would greatly
appreciate it.

It sure appears to me that modern T8 fixtures with electronic ballasts
have a power consumption (lamps and ballasts combined) close to 32 watts
per 4-foot lamp (bulb). Nearly enough 100% of this becomes heat
in the room, whether at the fixture or where the light is
absorbed. Multiply by 3.41 to get BTU per hour.

T12 fixtures with 40 watt lamps and "commercial grade" magnetic ballasts
consume roughly 45-46 watts (including ballast losses) per 4-foot lamp.
Subtract maybe 5 watts for using 34 watt lamps instead of 40 watt ones (I
suspect the ballast losses will increase a little).
Residential fixtures may do about the same or they may do less, since
many garbage residential fixture ballasts and "cheap shop light" ballasts
put out much less than full power. I have seen a few of these being
referred to as "25 watt" for 4-foot T12.

Nearly enough 100% of the power consumption becomes heat. Most becomes
heat at the fixture, some becomes heat where the light is absorbed.
Multiply the total power consumption in watts by 3.41 to get BTU/hour.

- Don Klipstein (don@misty.com)

 

[Harry Conover]

jeremiahfun1@hotmail.com (Jeremiahwd) wrote in message news:<e274b5da.0406230925.c283473@posting.google.com>...

I need to find out what the actual heat output for T8 fluorescent
bulbs is. I know that internally they create a lot of heat most of
which is converted to visible light by the phosphorus coating on the
inside; but how much heat is finally given off thermally that has to
be removed by an A/C system. Also how about the ballasts? Do
magnetic ones give off more heat than electronic and how much more in
general? If anyone could provide some direction I would greatly
appreciate it.

Jeremiahwd

Since essentially all of the fixture wattage is ultimately converted
to heat, simply assume that the total energy emitted by the light
fixture must be removed by the air conditioning system.

Harry C.

 

[Kevin McMurtrie]

In article <e274b5da.0406230925.c283473@posting.google.com>,
jeremiahfun1@hotmail.com (Jeremiahwd) wrote:

I need to find out what the actual heat output for T8 fluorescent
bulbs is. I know that internally they create a lot of heat most of
which is converted to visible light by the phosphorus coating on the
inside; but how much heat is finally given off thermally that has to
be removed by an A/C system. Also how about the ballasts? Do
magnetic ones give off more heat than electronic and how much more in
general? If anyone could provide some direction I would greatly
appreciate it.

Jeremiahwd

100% of the power consumed turns into heat. Some of the power is light
for a little while, but that still ends up turning into heat unless
you're shining it outside the building.