Rule of Thumb Heating Chart
Based On Room
Size With Eight Foot (8') Ceilings |
| Sq Ft Room |
Watts Of Heat Needed |
|
Sq Ft Room |
Watts Of Heat Needed |
| 50 |
500 |
275 |
2750 |
| 80 |
800 |
300 |
3000 |
| 100 |
1000 |
325 |
3250 |
| 125 |
1250 |
350 |
3500 |
| 150 |
1500 |
375 |
3750 |
| 175 |
1750 |
400 |
4000 |
| 200 |
2000 |
450 |
4500 |
| 225 |
2250 |
500 |
5000 |
| 250 |
2500 |
550 |
5500 |
*Items marked in yellow need 240
volts, 120 volt heaters only go to 1500 watts
|
Rule of
thumb charts are based
average insulation and homes built in 1980 to present day with zero degree
weather,
houses older or in a colder environment should go with a larger
wattage
This is only a guideline please consult a licensed contractor engineer for a true heat load
analysis |
Rule
Of Thumb Chart is based on 10 watts per sq ft:
example 8'x12' room =96 sq ft
room 96sqft x 10 = 960 watts needed to heat room.
|
| Ceilings higher
then 8' should use the 1.25 x cubic ft rule of thumb please see below
for How Much Heat Do I Need
|
| This chart
is not intended for Garages, Workshops or Warehouses or any other
room with poor insulation, garage doors, overhead doors and high
ceilings |
| Additional Notes |
| |
| If you are trying to heat a bathroom and
you have 120 volts go w/ 1500 watts heater - if you have 240 volts go with 2000
watts |
| Always consult an
electrician if you don't know what power supply you have or call
us at 800 416 1298
We Can Help
|
When sizing a heater to heat your
bathroom, you have two variables:
1 ) you have some other form of heat in there
currently, i.e.:
hot water baseboard, forced hot air or radiant floor heat
2 ) you have no heat in your bathroom currently
When heating a bathroom with
NO current heat, I like to oversize the heater more then I would
any other room because you want to get the room up to 80 +
degrees and you want to do it at a fairly quick rate.
The
standard sizing rule of thumb:
1 square foot equals 10 Watts, so a 100 square
foot would require a 1000 Watt heater
Technique is 10 watts per sq ft
(example 10’ x 10’+ 100 Sq Ft) 100 sq X 10 watts = 1000
Watts
With a bathroom heater I like to substitute 10 watts
Per Sq with 12-15 watts per sq ft
based on if it’s a house
older then 1980 and if you are in a northern or southern
climate
Are you going to heat the
room all day, or only while you’re in the shower?
I find this is a very important question
ask because this will reduce your selection of heaters
depending on if you just want to roll out of bed and turn
the heater on in the morning and shut it off when the last
person using the bathroom in the morning is done. Or do you
plan on heating the room all day? If you just want to heat the room in the morning and get the
heat up quickly you are going to need a fan forced wall
ceiling heater because the will move
the air quicker. A baseboard heater, convector heater,
radiant cove heater all have no moving parts so while they
will heat the room, it will take a while. Baseboard,
convector and radiant heaters will work if you are planning
on heating the room throughout the day.
Do you plan on using 120 volts or 240 volts?
Knowing your voltage is the most
important thing when buying an electric heater. 120 volt can only work on smaller
heaters 500, 750, 1000 or 1500 watts. Wattages greater than
2000 watts will need 240 volt versions. A 240 Volt heater can uses wattages of 2,000, up to 10,000.
An
electric heater will either be a rated for one of the two
voltages available in a residential household 120 volts or
240 volts. If you buy a heater that's rated for 240
volts and you use 120 volts it will not work, and most
likely the extra power will cause the heater's motor to
malfunction.
Quick Note: Over the years
the power companies have been raising the voltage to your
home or office.
110 volts, 115
volts, 120 volts, 125 volts
All four
voltages will work with the same heater
220 volts, 230
volts, 240 volts, 250 volts
All four
voltages will work with the same heater
NOTE: 208 volts
is NOT the same as 240 volts it’s a total different voltage.
