Electric Floor Heating
System
Tips For Choosing
And Installing An Electric Floor Heating System
by Georges
Selvais
No one takes
a cold shower in the morning, and everyone prefers to step on
a warm floor.
Warm floors
have been around for a very longtime. The Roman Empire was known
for its luxurious public baths* with hot water springs that circulated
warm water under the marble floors.
Nowadays,
you don't need a hot water spring in your backyard to enjoy the
comfort of Roman bath floors.
A thin electric mat installed in thinset cement or self-leveling
cement, controlled by a timer-thermostat with an in-floor sensor
will cost $500-to-$600 for an average size bathroom and it will
operate on less than 10 cents a day of electricity.
Conceptually,
these products are very similar to electric blankets. They are
made of a heat resistance wire that serpentines over a supporting
material. They are safe, relatively easy to install, and extremely
energy efficient. Products sold by WarmlyYours.com Inc. (www.WarmlyYours.com
), DK Heating Systems (www.dkheating.com ), and NuHeat (www.nuheat.com)
have been installed for approximately 10 years in Europe and in
north America. In the last two years Heatway Inc (www.heatway.com)
and Flextherm Inc. (www.flextherm.com) have introduced new products
in the US market.
All these
products are 1/8" thick and they can easily be embedded in thinset
cement without elevating the floor more than 1/8".They will all
draw 8-to-15 watt/ sq. ft. and each of these manufacturers offer
rolls of different sizes so that the installer can make cuts-&-turns
to fit the custom shape of each room. NuHeat offers standard size
rectangles and special orders made-to-size mats. WarmlyYours.com
offers both rectangular mats and rolls. These rolls or mats always
have to be used entirely and the cuts-&-turns only allow you
to cut the supporting material to facilitate the turns (see illustration).
You never cut the heat resistance wire!
With so much choice in the
market, the DIY consumer is having a harder time to choose. Once
installed the product is hidden under the floor. Even the thermostat
can be hidden in a closet since it functions with a sensor in
the floor and it does not measure the air temperature.
Products of
equal watt/ sq. ft. will warm the floor to the same temperature
and at the same speed.
Finally, many
timers and thermostats offer comparable functions, so the real
difference is the ease of installation
and the level of technical support offered by
the manufacturer.
What makes the installation easy
?
· The mat
or roll construction: You want to look for a product that
can be installed in a single layer of thinset cement rather than
two layers. This is faster and easier. You also want to find a
product where the fiberglass (or other supporting material) forms
an umbrella protection over the resistance wire so that your trowel
can glide over the fiberglass net without risk of nicking the
wire. Some products weave their wire over-and-under a fiberglass
net. In that case the resistance wire will always appear on the
surface and you face a greater risk of nicking the cable with
your trowel
·Thickness of the cold-lead wires that connect the heating
rolls to the thermostat: You want the thinnest cold-lead wires
available (1/8" thick), so you can easily cover them with thinset
cement like the heat resistance wire. If the cold-lead wires are
thicker you will need to chisel a grove in the cement slab, or
use a circular saw to cut a groove in the plywood sub-floor or
backer board to maintain the floor level flat.
· Length of the cold-lead wires: You want cold lead wires
that are long enough to connect to the thermostat without additional
cut-&-turns of the roll to bring the roll closer to the thermostat.
·Vendor Technical Support
Look for a vendor who will design an installation layout customized
to your own floor plan. Understand that the heat will not extend
very much laterally through conduction. In most cases the heat
will extend 1.5" away from the wires but not more.
Therefore
it is important to lay the heating mat 1" or 2" under the toe-kick
space to make sure you don't end-up standing with hot heels and
cold toes in front of your vanity.
Attention
to details and precision in your customized design layout will
save you time and cost during the installation.
How
to make a successful electric installation ?
Make sure
you have a good ohm meter and continuity checker. Check the ohm
resistance at least three times: before you start, after you laid
the heating element in thinset cement, and after you installed
the tile or stone over the heating elements. There is no need
to fire-up the system with 110 volts to make sure you have a working
installation.
A proper ohm
reading will confirm that you have no break in the cable, and
the continuity check will assure you that there is no short passing
through the insulation that separates the core wire and the ground
shield. Any DIY who can install ceramic tile can install a floor
heating system and bring the cold lead wires behind the thermostat.
However to install a timer and thermostat and connect them to
the floor heating you need to hire an experienced electrician.
Once properly
installed these floor heating systems are a marvelous part of
our daily comfort. They are totally silent. They do not circulate
hot air that carries bacteria and toxins. They have no moving
parts and require no maintenance. Whether you plan a new bathroom,
a kitchen, a sunroom addition or a basement conversion, floor
heating is the sensible solution for comfort and energy savings.
They can be installed under tile, stone, vinyl, carpet, hardwood
and laminate floors.
Georges
F. Selvais, 
