Where to begin
Created Oct 14 2005 by Walus, Mirek
Suitable for new construction or remodeling applications,
electric floor warming systems include a network of cables sewn into strong
fiberglass mesh 20" wide and of various lengths installed in the mortar just
below the tiles.
The larger the coverage and longer the mat - the more
powerful (more Watts) it is.
Double insulated and grounded cables gently warm
the tiles, operating on ordinary house current.
While using a professional
electrician is advised for those not comfortable working on electrical
installations, these systems are generally easy to install and will not
compromise the integrity of the tile installation.
ELEKTRA heating
mats are ready to be installed out of the box, but it should be noted that a
fair amount of planning and some preparatory work is necessary.
Designing and
then as a result of good planning consequently installing a floor warming
system can be done at the same time when planning and preparation for
new floor installation is done.
-
First, take a
good look of the area to be warmed.
Calculating the total square
footage will require collecting information from the blueprints of the room or
actually measuring the actual area itself. If possible - this usually is a
better method.
Note that areas that are inaccessible or under cabinets,
vanities, shower stalls or plumbing fixtures should not be included - there's no
need to heat floor area that won't be walked on or at least barefoot touched !
When making the calculations it is advisable to design a layout that
considers actual use and traffic patterns in the area to be warmed.
-
Once knowing the
square footage to be warmed - decide if 9 Watts/ sq. ft. is enough or 14
Watts/sq. ft. will be better. Simply said - multiply the square footage to be
warmed by 9, write down the answer and then multiply the same area by 14.
Compare both numbers. If one looks high go with the other. In general -
for larger coverage such as over 70 sq. ft. 9 Watts/sq. ft. is usually enough.
Floor
heating in contrast to air heating or space heating where lot of heat is applied
to small space and then hopefully blown all over is a little heat per square
footage applied over large areas.
"Know your limits". Tips. Re:
9W/sq.ft. vs. 14W/sq.ft.
For smaller
coverage either one is good, depending on the climate zone and flooring
type. E.g.:
For ceramic tiles
9 Watts per sq. ft. is OK.
For stone or
slate go 14.
For larger areas
remember about technical limitations of the power source.
1200 Watts
powered by 120V AC will use 10 Amps current (1200W / 120V = 10 Amps). Look at
the breaker on the electrical panel. Is it 15 A? That's your limit on that line
providing that NOTHING ELSE besides your permanently wired floor heating gets
connected there. 15A @120V means 1700W.
@ 230V - almost
double that.
The complete
system consists of one or more mats and appropriate line-voltage thermostat,
preferably equipped with floor temperature sensor.
In general, and aside from
many available sizes, there are several versions of the mats and combinations
thereof:
-
Powered on one end or both ends of the mat.
-
Powered by 120 or 240 Volts AC.
-
9 Watts/sq.ft. (100W/m2) or 14 Watts/sq.ft. (160W/m2)
Double-side powered mats are thinner, but both cold tails
(power supply cords) need to be connected to the power supply terminals at the
dedicated line-voltage thermostat. Single side powered mats have only one such
cord.
Although compatible with most line-voltage thermostats, it is highly
advisable to use the thermostats with floor temperature sensing capabilities
specifically manufactured for radiant floor heating. For the thermostat voltage,
minimum and maximum power requirements have to agree with the mat (or set of
mats).
How to choose suitable line
voltage thermostat?
Air temperature sensing thermostat:
When heating of the room and the floor is to be
considered the primary function of the system.
Floor temperature sensing thermostat:
Heating of the room is welcomed as a secondary result and
therefore thermostats with a floor temperature sensing probe is of such
importance.
ELEKTRA UCCG or MTC series thermostats:
UCCG offers
built-in GFCI protection and programming functions. If the thermostat does not
have GFCI protection it can, and often should be added.
Please check with
your electrician. Adding GFCI to the setup with MTC thermostat - if needed - is
usually a very simple and inexpensive upgrade.
A complete system often can be installed using an electric
drill and other simple tools but please note that scissors are much better
than the utility knife to cut the fiberglass mesh!
Feedback is something that really keeps us going.
Please comment on the FORUM
or send us your comments or requests for
any specific topic that you would like us to feature.
