The usual answer is YES!  We can install radiant heat under an existing floor, on top of an existing floor, in new concrete work, in walls, in ceilings, under tile, under hardwood floors and more. Today there are so many options for installing radiant heating systems it's harder to consider where we can't put it.   

What runs through the pipes and how big are they?

The usual answer is water but a non-toxic anti freeze called Glycol can be added for extra insurance.  The pipes vary in size, standard residential sizes are 1/2", 3/8" and 5/16" tubing. 

What heats the water?

The usual answer is a high efficiency hot water boiler.  There are many options we have used including:

1. Solar hot water heater

2. Geothermal hot water heater

3. Instantaneous hot water heater

4. Existing gas or electric water heater (usually for a small area)

5. Existing boilers, either gas, oil, wood or coal fired.

6. Electric boilers

What happens if a pipe breaks

This is a very rare occurance.  Pex tubing has been around for over 30 years in heavy use and has been lab tested to remain stable in performance for a life span over 100 years.  The usual scenario occurs if someone has put a nail or screw through the pipe, which then becomes a slow leak.  The tube is very easily coupled and repaired.  If it is behind sheetrock it requires installing a new sheetrock patch, if it is in concrete we would thermal image the area to determine exactly where the tube is, take out an 8" X8" patch, then re-couple the tube and repair the patch. 

1. First and foremost is the even comfort of the heat.  Radiant heat will stay within 1 degree of your thermostat setting.  It warms the floors so barefoot areas are much more comfy.

2. Radiant heat takes longer to heat up than hot air systems.  Normally we do not use programable thermostats with more than a 2 degree set back during unoccupied times.  Radiant heat is so much more efficient than hot air or baseboard heat that it will still give you a tremendous savings with added comfort by just leaving the thermostats alone. 

3. Home drafts are virtually eliminated.  Even with old windows and doors there is so much less air movement with radiant heat that homes experience much less infiltration and drafts. 

Is it affordable?

Radiant heat is more money up front than tradiational hot air or baseboard hot water systems but the operating costs and added comfort significantly out weigh the initial investment. 

Plan on spending 20-40% more for the initial installation of radiant heat than hot water baseboard or hot air.

You will realize operating savings for the life of the system at 30-60% over the hot water baseboard or hot air system.

The earlier in the planning stages you can involve your heating contractor, the lower the installation costs and the greater the choices will be for installation methods.    

Should I insulate under the radiant heat?

Absolutely! In fact without insullation it may be like heating your home with the windows open. 

Not only do you need to insulate but it really makes a difference on what type of insulation.  Radiant heat very easily penetrates standard fiberglass insulation.  A low emmisivity rated radiant barrier (aluminum faced) insulation with a 3/4" or greater air gap, should be directly under the tubes installed under the floor.  In concrete or gyp-crete installations where there is no open space below we still want to make sure the insullation value down is greater than the thermal resistance up.  In concrete slabs especially we should remember to insulate the edges of the slab. 

Do I need to do the whole house?

No.  In fact most installations are for those hard to heat areas and the barefoot areas that you will most appreciate.  Bathrooms, kitchens, high ceilings, foyers and sunrooms are the most popular.  The radiant heat systems combine very well with other forms of heat such as hot air, baseboard registers or cast iron radiators.

What is the difference between high mass and low mass radiant systems?

There are two types of radiant heat being installed today with variations on each.  The general rule is that a high mass system that is installed in a rock like base (concrete, gyp-crete, wet bed tile) has a lot of material to heat up, which retains and gives off the heat very evenly.  These systems use mixed water tempeeratures from 80-140 degrees. 

A low mass system or staple up radiant system uses the same tubes that are embeded in the high mass system but they are usually installed  under the floor.  Since a lot of the heat is spread to the above surface by heating the air in the space then heating the floor, it requires more heat to get the same type of result.  A low mass system utilizes temperatures from 120-170 degrees.

There are hybrid systems between these two that involve aluminum panels as intergal parts of the subfloor.  These hybrid systems utilize similar low temperatures as the high mass systems and yet are installed under stanadard sub floor or are actually built into the sub floor on new construction.

Whenever possible and practical, the lower the operating temperature the higher the energy savings.  This may differ between installations but a general rule of thumb is that for every 3 degrees you lower the water temperature you can potentially gain 1% energy savings during steady state operation.