The Letter

Joe Cocker – best cover artist ever. Period.

Joe’s version of “The Letter,” from 1971′s Mad Dogs and Englishmen album and film.

And speaking letters, I received a very happy one in my inbox this week, courtesy of one of my favorite industry writers, Bob Mader of CONTRACTOR magazine, regarding…wait for it… a new study.

Studies can tell us many things.  And for every study that says “yes,” there’s another study that says “no.”  Personally, I’m still looking for the study that proves slightly overweight, balding, middle-aged hydronics trainers are irresistible to women.

But I’m not holding my breath.

Anyway, Bob wrote this week of a new study in Canada, commissioned by Canada’s “Beautiful Heat” campaign (check ‘em out here) ,  that backs up something many of us in the business have long maintained:

Radiant heating is more efficient than forced air.

Here’s the skinny (and you can click here for the details): Canadian consulting firm ICF Marbek conducted energy simulations on a variety of homes in six different parts of Canada and concluded that radiant heat can save up to 17% when compared to forced hot air.

As with any study, the Devil is in the details.

In existing older homes, built pre-1980, the study says single story homes could reduce heating costs by around 5%, while two-story homes could reduce costs around 12%.  In newer homes those numbers ranged between 5 and 10%. Overall, that turns out be a dollar savings (US currency) of anywhere from $36 annually on the low end to over $210 on the high end.

It’s in multi-zone systems with setback in basements and living rooms at night and in bedrooms during the day, that savings mounted even more.  A 2-degree setback resulted in heating cost reductions of over 10.5% in new 2-story homes and nearly 12.5% in older 2-story homes.

Now here’s the part that surprises me: with a more aggressive setback of around 7-degrees, the savings in new homes grew to over 15%, and 17% in existing homes.

Color me orange on this one – I maintained for years that aggressive setbacks with radiant weren’t – from an energy savings standpoint – a very good idea.  The theory was that it would take more energy to recover from that deep of a setback than it would take to simply maintain the set point.


It’s also often been said that since radiant heat is just plain different (it’s not air-based), you can be more comfortable at a lower thermostat setting than with forced air.  Again, this study bears that out.

The study says that to maintain ideal comfort, thermostats could be set an average of 4-degrees lower in single story homes with radiant, and nearly 6-degrees lower in two-story homes (both new andexisting).

Some more details: all homes were modeled with your standard single zone forced air system, with the thermostat most likely placed in the main floor hallway (which is dumb, because no one hangs out in the hallway, but that’s another blog!).  The radiant systems were modeled as a 3-zone system (basement, living area, bedrooms).

So what conclusions can we draw from this study?

1. Radiant heat certainly can save money in heating costs compared to forced air.  We’ve always known that, but here’s a study that can bear it out.

2. Saving a couple hundred bucks a year on heating costs is nice. Really, really nice – but it won’t make anyone rich or change anyone’s life.  Does it add up over time? Absolutely, but be careful not to fall into the “payback” trap (click here and here to review).

3. There is no substitute for comfort, and when it comes to comfort, there’s no substitute  for radiant.

4. Zoning is good. Don’t skimp on the zoning.

So, what are your thoughts on the study? How do you plan to make use of the data?

Inquisitive sorts like me want to know!!

And if you’re going to come in through the bathroom window…

…at least make sure the tile floor is heated!

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