Radiant Heating Options

A viewer from Montreal is building a new home, and asks John and Matthew about radiant heating options.

  • Brad W

    Since the warm board and tubing are installed earlier in the construction process they will be subject to greater abuse. I am assuming the reflective surface and, more importantly, the tubing are tough but extra steps should be taken to protect the flooring during the ongoing construction process. Leak testing prior to final finishing of each zone would also be a nice idea.

    Remember also that air conditioning must be done using a separate system.

  • Matthew North

    Hi Brad W – Happy New Year! You are correct about the precautions required due to the fact that the warm board and tubing is installed early in construction. We are just finishing the framing on a new home here in Calgary and the warm board and tubing is already installed on two levels before the roof has been framed. In terms of construction sequencing, is strange to see, but it does fit together really well and the spacing is perfect. I am going to take some photos and post them. We have had to thoroughly protect the warm board with plywood for a couple of reasons – the first is that it is as slippery as hell! The second is because we want to protect the product from damage, ice and snow as you had pointed out in your comment. And yes, they get pressure tested before the flooring is installed. In this house we have and HRV as the main fresh air supply as well as a single two stage furnace with a zone system to operate the air conditioning system.

  • RickB

    Some have argued that full on radiant heating is not appropriate or desirable in super-tight super-insulated homes.

    See for instance:


  • Frank

    Great Topic.

    A couple of comments regarding something Matthew said in the segment. There are 3 types of heat transfer convection, conduction, and radiation. All three are involved to varying degrees in all heating systems (see attached diagram). Unlike forced air systems, radiant floor heat does little to heat the air within a home. It’s primary heat transfer mechanism is radiation. Thus it heats the mass of the floor, the mass of the building (walls, furniture, casework, etc.) and the occupants of the home.

    As a result it has a few drawbacks:1. You cannot quickly raise or lower the temperature in a space by adjusting the thermostat up and down like forced air systems because it takes a long time for the mass of the building to heat up and cool down. 2. Objects in direct line of sight can block some of the radiation (think fire or the sun where one side is very warm and your backside is much cooler.

    Overall it still is one of the most efficient means of heating a space provided you have the system sized appropriately for the space, its envelope heat loss, and the climate for your area, especially if you have high ceilings. Since it does not heat the air (except a little bit that passes near the floor) it is warmer near the floor than at the ceiling and that is where we do most of our living. (I tested this in my own home during the winter. The floor was 81F, 68F at 5 feet and 61F at 15 feet ceiling. While this seems counter intuitive that is because most of us are used to heat rising in the form of forced air systems.

    There are also no thermal air movements that can be the source of drafts near colder exterior windows and walls. You must however as Matthew stated ensure you get the components close to the area where the heat loss is greatest – the exterior walls. You need to also run the hottest part of the loop close to the exterior walls.

    If you use this type of radiant heat it is best to get some expert advice on sizing and layout of the system. There are a lot of mathematical calculations involved in sizing the system and if you make a mistake you could end up with an undersized system incapable of keeping your home warm.

    Here is a link to another system components Quik Trak system made by Uponor that works well for retrofitting in an existing residence. It is 1/2 inch tall and can be used in remodels. I have used the system and it works well. It can be used on walls such as under tile backer board in a shower.


  • Frank

    One attachment did not make it on my last post. Here it is.

  • Frank

    Also something wrong with the link at the top of the page and the photo. Link on the bottom works. Here is the photo again.

  • Frank

    Must be tired wrong photo. One last time then off to sleep. Hopefully Matthew can delete my mistakes.

  • http://www.mindfulhomeandbody.com sabrina

    Very informative. As a Feng Shui consultant whose primary concern is health, I was wondering if you could tell me what the impact is on the body to receive the heat from flooring and if water or electric is better.
    Thank you so much

  • Matthew North

    Sabrina – thanks for your comment – I am glad you found the segment useful – your question is a really good one….. I have water based radiant heat in my home and find it very soothing – particularly when the temperature is really cold outside – I am curious if any of our viewers have any more expertise to answer Sabrina’s question?

  • Terri

    In response to Sabrina’s question regarding electric or hot water…I have little experience with the in-floor variety, but more with baseboard heaters. I preferred the hot-water heat too, as it was more even and steady. Like Matthew, I found it more soothing, and I wonder if there’s something to the EMF angle. There are those that believe we should limit our exposure to the electromagnetic radiation fields caused by all electrical appliances, outlets, etc. If the wiring is below a ceramic or stone material, perhaps the field is weakened?

    (I know some people might find EMFs to be “out there” as a topic, but I know an electrician who has branched into measuring these fields for clients and who strongly advocates corrections in homes to avoid high readings near beds, etc.)

  • http://mindfulhomeandbody.com sabrina

    Thanks for your comments. I agree with avoiding high readings near beds or in rooms where the person spends a lot of time in. We use dowsing rods to measure the field’s impact on the body and once a “leaking” appliance has been removed the person does feel better.