To heat the floor, or not to heat the floor…

…That is the question.

Well, sometimes it is, and the answer opens up a whole lot more issues than just keeping your feet warm.

Many people over the past 15 years or so have built homes with radiant in-floor heating systems. It’s a nice feeling to have warm feet as you walk on the floors and it did a pretty good job heating your home.

So why did so many switch? First of all, the technology was there and it became easier to put in place with electric, oil and gas-fired boilers. But let’s back up a couple of steps and think about why the floors were so cold to start with. I call it “Cold Basement Syndrome” and it was the result of foundations that were either poorly insulated, or not at all. The upper floors were decently warm but the floor on the main level felt cold due to the cold basement. So in went the radiant heat systems and floors were now warm.

Then came the growing popularity of heat pumps, which also had cooling capabilities, so people were installing them, too.

Wait a minute! An in-floor radiant system with boiler AND a heat pump to cool? Why on earth would someone spend the money on both? Where’s the disconnect here? Considering that due to building code requirements in new houses you now must have a ductwork system in place anyway for air circulation, and that the foundations must be insulated, why spend money on the in-floor system when the heat pump can do it all? Still want that “warm-floor” feeling in your ceramic tile bathroom or kitchen in the morning? Install electric radiant heat pads in these areas that come with programmable thermostats so it’s nice and toasty when you get up in the morning and then shuts off after you leave.

Remember that the efficiency of oil/gas/electric boilers are in the 85-97% range. While that may sound good at first glance, you’re always getting less out of it than you put into it. Put another way, you are buying more energy than the system can give you. On the other hand, air source and geothermal (ground source) heat pumps operate at 300-500% efficiency, meaning that for every unit of energy you buy to run the system, it puts out 3-5 units of energy for heating, depending on the unit. That’s a nice return on investment via huge reductions in energy usage, not to mention the reduction in greenhouse gas emissions.

On top of that, the heat pumps also give you the ability to cool and dehumidify if you wish (anyone in Nova Scotia experience frequent fog/high humidity?!). Don’t need cooling, you say? No problem; you simply turn off the heat pump and the HRV (Heat Recovery Ventilator) still runs with the air-exchange system to keep inside air fresh and cooler than outside. If there’s a heat-wave then put the heat pump on cooling mode for only as long as needed.  As an added bonus, the geothermal system will also pre-heat your domestic hot water for even further energy, and money, savings. This is a significant saving as hot water heating is #2 in energy consumption in our homes next to space heating. With a geothermal system on cooling mode in the summer, it dumps all the heat it pulls out of the house into the hot water system so that you spend virtually nothing to heat your hot water. If the house is suited, Solar panels can be added to pre-heat domestic hot water and reduce the need to purchase energy.

Some will say if you build slab-on-grade style that you have to do in-floor heating so the slab isn’t cold. If the slab is properly constructed and well-insulated (never just minimum code) then there is no reason for that slab to be cold. Every building should have passive solar features taken into consideration as much as possible so that free solar energy is absorbed by that slab during the day and released slowly at night.

You will often hear me say that when you invest in planning and constructing a very efficient building envelope, your heating system will have much less work to do, thereby using much less energy, and that means a lot less money for you to spend. This is what all buildings should focus on so make sure your builder is addressing the items that affect this directly – it’s the easiest, most effective way to reduce energy consumption.

Whether new construction or retrofit, every home is different and should be evaluated on its location, orientation to the sun, integration into the land, occupant requirements and desires, size, configuration and budget. When these items are appropriately addressed, and your home is looked at as the complete system that it is, you’ll end up with a comfortable place to live that costs you less, is worth more and uses far less energy.

It’s an all-around win.

Advertisements

Leave a Reply

Fill in your details below or click an icon to log in:

WordPress.com Logo

You are commenting using your WordPress.com account. Log Out /  Change )

Google+ photo

You are commenting using your Google+ account. Log Out /  Change )

Twitter picture

You are commenting using your Twitter account. Log Out /  Change )

Facebook photo

You are commenting using your Facebook account. Log Out /  Change )

Connecting to %s

%d bloggers like this: