Reuben's Home Inspection Blog

Boilers Vs. Furnaces

May 12th, 2009 | 4 comments

Whenever I get around to building my dream home and money is no object, I won’t be using a furnace for heat.  I’ll be using a boiler.  Gas fired forced air furnaces are the standard for homes in Minnesota, but boilers have definite advantages over furnaces, with comfort and silence being the two biggest.

Boilers provide hydronic radiant heat by heating water that is circulated through copper or PEX tubing.  The tubing can be fed through large old radiators, modern baseboard heaters, or hidden in walls, ceilings, or floors.  Wall and ceiling heat is rare – I’ve only inspected two homes with in-wall or in-ceiling heat, and there wasn’t much I could look at. It took me a while to figure out how these systems worked!  In-floor heat is the best.  The most common way of installing in-floor heat is by laying PEX tubing on the floor and pouring concrete over it.  If you’re not a fan of shoveling snow, you can even run the tubing under your driveway and walkways.

The photo below shows a home we inspected that had a partially heated driveway – it’s easy to tell where the heat begins.

Heated Driveway

Forced Air vs In-floor Heat Boilers provide more comfortable heat than furnaces because the heat is even – especially if it’s installed in the floor.  Floor heat allows everything in the room to be warm, including your toes.  Even if a home is heated with baseboard heaters, the heat is more comfortable than forced air.   Radiant heat is a much more comfortable heat than forced air.

The other big advantage that boilers have over furnaces is that they’re silent.  While newer homes with properly designed furnaces can have variable speed blower motors that cut down on noise, boilers are always silent.  If I inspect a home with a boiler and I hear gurgling or bubbling in the pipes, I know there’s a problem with the system and I tell my clients to have it fixed. It’s usually a matter of air in the lines.

A couple other advantages worth noting are cleanliness and zone control.   Because boilers don’t blow air (and dust, and alergens…) all over the house, you’ll have less alergens in the air, you’ll never need to hire someone to clean your ducts, and you won’t need to worry about your two-year-old putting Cherios in the vents.  Boilers are also much easier to conrol by zone - most forced air systems don’t have zone controls, and the ones that do typically don’t have more that two zones.  I’ve never seen more than three.

If boilers are so great, why aren’t they the standard?  No one wants to spend the money.  Boilers cost much more than furnaces and they don’t provide a way of cooling a home.  To cool a home with hydronic radiant heat, a completely separate forced air system needs to be installed, which dramatically adds to the installation costs.  In older homes without ductwork installed for a furnace, it’s an expensive project to add central air.

Reuben Saltzman, Structure Tech Home Inspections – EmailHome Inspections Saint Paul

4 responses to “Boilers Vs. Furnaces”

  1. Doug
    May 29, 2009, 4:16 pm

    Great blog, I recently purchased a vacant home and have found much useful information here. A question regarding this post: are furnaces more efficient than boilers? The highest efficiency boilers I’ve seen are listed at 92-94%, but furnaces at 98%. On the other hand, since water retains heat better than air, it seems that a boiler should actually be more efficient. Web searches have not been illuminating. Thanks

  2. The Buyer Should Be There | Reuben's Home Inspection Blog
    August 11, 2009, 5:14 am

    [...] entire boiler system with a forced air furnace, so I included a link in his report to my blog about furnaces vs boilers. [...]

  3. John
    January 3, 2010, 8:56 am

    Beware of the thought that having boiler heat is all roses. I live in Michigan and have a home that was built back in 58. I have been dealing with leaks in the system under the slab and am now looking at a very big repair bill to fix this problem. I have also lost a lot of sleep over this. Not just in bubbles but in the fear of a leak.

  4. George
    May 13, 2013, 6:39 pm

    This is a great easy to understand article. I think a lot of people get confused between the differences. The newer boilers are also greatly more efficient then those of only a few years ago.

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