In article ,
whisky-dave wrote:
On Tuesday, 5 December 2017 22:16:37 UTC, charles wrote:
In article ,
whisky-dave wrote:
On Tuesday, 5 December 2017 16:30:01 UTC, T i m wrote:
On Tue, 5 Dec 2017 07:35:02 -0800 (PST), whisky-dave
wrote:


It is a 700, 1300 or 2000W heater at 240V.

So how many would I need for either my office of the labs. How many
of the above heaters would I need ?

You need to determine the volume of the room, the starting temperature
and the final required temperature and how long you have to heat up the
room. From that data, YOU can determine the kilowatts required.

Yes I know, but did you know that the outside temerature varies from
day-day and that the number of students numbers 100+ coming and going
through swing doors will, also affect the temerature and that 100+
studetns working in the lab for 4 hours will result in a differnt
temerature if there were half a dozen. And that workman opening those
doors and coming through the lab with rubble on wheel barrows is another
vairiable, and through out most of teh day because the building can only
be accessed by RFID cards that they won't give them to the builders that
they leave the doors wedged open to the outside world so they can freely
come and go. even when the builders finsish around 3:30-4pm the doors
were wedged open at 5:30pm when I left, but it could be the students
doing it there's no way to tell.


Heating systems need to be designed for the worst conditions. If the
outside temperature gets too hot or if you have 100 students in the lab,
then your heating system won't come on. That's what thermostats are for.

--
from KT24 in Surrey, England