Do you wish for warm floors? Radiant floor heat is easier and less
expensive to install than you think. There are several installation
methods depending on your needs and radiant heat can be used either
as a primary or secondary heating source. Both electric and hydronic
radiant heat are available so there's sure to be an option that works
with your home.
Radiant Heat Installation
Why would you want radiant heat in your home and what are the
Comfort is the biggest benefit. With radiant heat, heat is distributed
evenly through the floors, warming them and then rising up throughout
the rest of the room. When the floors are warm, the objects in the
room (couches, chairs, and so on) become warm, and you become
warm and comfortable. Radiant heat allows you to keep the average
temperature a few degrees lower than you're used to but feel just as
warm or even warmer. This saves energy and directly saves you money.
Radiant heat is also silent with no creaking, rattling, banging, popping,
humming or whistling. And there are no visible components with
radiant heat so it will always fit in perfectly with your style.
Why is radiant heat better than conventional heating systems?
Comfort. Even heating eliminates the pockets of hot and cold typical of
traditional radiator or convection heating systems. Instead of being
warm right next to the heater and freezing on the other side of the
room, radiant heat keeps the same temperature throughout the room
by allowing heat to naturally rise.
The 4 basic methods of installation are In-slab, joist, overpour, and
wood panel tracks. When you decide to install radiant heat, you'll need
to decide how you'll be doing the installation. This decision is largely
based on the space available and the layout of your home.
If the concrete slab has not yet been poured for new construction or a
large remodel, an in-slab installation is the best way to go. With this
method, you will lay out your loops of tubing, and then pour the slab.
When hot water circulates through your PEX, the entire slab will heat
up and radiate its heat into the room. The slab becomes a large thermal
mass and will stay warm for a long time, meaning that your room will
stay warm for a long time with little energy usage. This is also the most
cost effective method. When installing in a slab, it is especially
important to pressure test. If there is a leak, you want to know before
you pour the concrete!
If your floors are down but you have access to the joist spaces beneath
them, joist installation is for you. When doing a joist installation, you
will need aluminum joist trak panels to secure in the joist spaces and
push the tubing into these panels. The aluminum panels will heat up
and hold their heat to warm your room. With joist installation, you can
also use suspended pipe installation where you do not utilize the
aluminum panels. While this is less expensive to install, you will need to
run hotter water through your tubing and it will not heat your room or
hold the heat as well as with the aluminum panels. If you already have
a slab, and do not have access to the joists, there are 2 more options
If you can raise your floors 2-3 inches, you can do an overpour of a
lightweight concrete (mud or gypcrete) onto your existing slab. With
this installation method, you will lay the PEX tubing onto your existing
slab and then pour another 2 to 3 inches of concrete on top. The top
layer must be poured so that there is a minimum of 3/4" of an inch
above the highest point of your tubing. The new layer of concrete will
be warmed in the same way as the in-slab installation, and this layer
will retain its heat and pass it to your room.
Wood Panel Track Installation
If you cannot raise your floors by 2 inches, you can utilize wood panel
track radiant heating that will only raise the floors about a half inch. For
this method, you can purchase wood panels and press PEX tubing into
the grooves cut out of the wood. Some panels (such as the Quik Trak
panels) have an aluminum heat transfer sheet built in and can easily be
combined to fit the size and shape of any room. Both straight tracks
and return tracks must be used to create your loops.
What You'll Need
Here's a list of the items you'll need for any radiant heat installation:
PEX Tubing: Crosslinked PolyEthylene (or PEX)- make sure that it
has an oxygen barrier for closed systems- flexible enough to bend
easily and strong enough to be approved by all major plumbing
and heating codes. 1/2" is the most common size for radiant heat
Manifold: The hub of your radiant heating system connecting to
the supply and return lines through supply and return balancing
manifolds, with as many ports as you have loops of tubing. If you
have more than 12 loops in your system, multiple manifolds may
be necessary. For half inch tubing, no loop should be longer than
Circulator Pump: Usually Taco or Grundfos, to circulate the water
throughout the system. If there won't be potable water involved,
a cast iron pump is a cost efficient way to get the job done.
Check Valve: To assure that water can only flow one way through
Water Tempering Control: Including mixing valves, I-series valves,
mixing blocks and Tekmar controls. Boiler water cannot go
directly into the hydronic radiant system, the water must be
mixed with cold water, ultimately sending a maximum of 150°F
water through your PEX to heat your floors.
Thermostat: The interface between you and your heating system,
the thermostat will control when the heat is turned on and how
long it stays on to achieve the desired temperature in the room.
Sensors: In-slab sensors will communicate to the thermostat the
temperature of the slab while floor sensors will communicate the
surface temperature of your floors to prevent any gapping,
cupping or warping due to excessive heat.
Expansion Tank: To maintain proper pressure within the system.
Air Eliminator: Removes all excess air from the system to ensure
silence and a steady water flow during operation.
Zone Valves: If you want to keep different rooms at different
temperatures, you will need to create separate zones.
Pressure Test Kit: Make sure to test the pressure in your system
to ensure that there are no leaks. Testing should be done at
maximum system pressure before, during, and after an
installation to be sure the system is running properly before you
put it to work.
A Loop CAD Design: If it's your first time dabbling in radiant heat
or you just want to be sure it's done right, you can get a loop CAD
drawn by a Radiant Certified Designer. A custom loop CAD with a
materials quote for your home is $150 from PexSupply.com.