Home & Garden Columns

Forced-air heating is stupid. I’m sorry if that’s what you’ve got; it’s also what I have, so you can feel bad for me, too. It’s not that we’re stupid. It’s just that heating air is a dumb way to heat space. It noisy, it’s dirty, it’s not especially efficient and it takes up a huge amount of space in a home. In case you’re not sure what I’m talking about, let me apologize, go back, slow down and explain what forced-air heating is. 

Most of us have forced-air heat if we live in our own houses. If you have an apartment or a very small house, you might have a wall or floor furnace, but the common heating in homes on the left coast is forced-air. 

Forced-air heating is made up of a big box (the furnace) that contains a set of burners, a blower and a “heat exchanger.” This last part is a magical place where noxious gases give up their heat to clean, cool air along the surface of a metal barrier. This barrier is called a heat exchanger and is the heart of any forced-air system. 

The system also includes a set of ducts (this is the really stupid part). These end up ruining lots of really nice houses by intruding into ceilings, walls, soffits and other places that we liked before the ducts got there. Taking an older house and adding forced-air is one of the best ways to screw it up. True, there are artists in the field who can do amazing things with minimal intrusion, but many purveyors of this mundane commodity lack said finesse and sort of molest these innocent, unsuspecting homes. 

Unfortunately, the alternatives (such as radiant “hydronic” heating) are just too expensive for the time being, and so forced-air is what we’ve got. Therefore, in the interest of conciliation, I’d like to offer some thoughts on how to proceed onto the field of battle. 

So you’re ready to replace your current heating system. Perhaps you have a forced-air unit and it’s old and you’ve been told that it’s time to upgrade. If you haven’t had an expert look at it in a year or three, it’s probably time for a check-up. Perhaps you’re concerned about your carbon footprint (or similarly, your heating bill). If any of these things are true, you should know that this is a very good time to get greener because you can get a huge tax break by buying a high-efficiency furnace and simultaneously lower your heating bill by 20-30 percent.  

Our fairly fabulous new president signed a bill back in February of this year (the American Recovery and Reinvestment Act of 2009) that gives a nice big tax credit (assuming you will be paying some tax this year) to people who buy certain pieces of equipment and among these are certain high efficiency furnaces. The tax break is 30 percent of the total installation cost and is capped at $1,500.  

This means that if you buy a furnace that costs $5,000 bucks, you can take $1,500 off your tax bill, making the furnace upgrade $3,500. Now a new furnace could be more than this with the addition of the accursed ducting, but if you already have viable ducting and a gas feed to the area where the new forced-air unit will live, the cost may be less than $5,000. In any event, this is a very good deal and will go poof at the end of next year.  

There are actually a whole bunch of incentivized items that can earn this tax credit. All offer a 30 percent tax credit with a cumlative total of $1,500. This includes Energy Star rated windows and skylights, insulation, water heaters, air conditioners and solar electric systems, but the list is much longer. These are all listed at energystar.gov/taxcredits. 

As I’ve mentioned, you win two ways with this upgrade (and maybe more if your furnace is old, dangerous, noisy or otherwise corrupt). Once with a big tax credit, which is basically free money, if you have to pay more than $1,500 in taxes, and again with a reduced heating bill for many years to come. Even those of us lucky enough to live west of the Sierras can benefit from a lower heating bill. If you have an old and inefficient heating system, you are probably throwing away 30–40 percent of your heating bill on waste heat. Modern, high efficiency, “condensing” furnaces, such as those that are approved as a part of the stimulus package can be 95 percent efficient or better, meaning that you could potentially save over 30 percent on the heating portion of your utility bill.  

We spend more on electricity than on heat, due to the mild climate, but a savings of 30 percent on your heating bill is very likely to provide more than enough financial benefit when calculated against the real cost of the furnace over a 10-year period (say $350 a year) and a new furnace will probably last twice that long and perhaps 10 years more than that, bringing the cost down to something under $125 a year. Keep in mind that energy costs are likely to ascend, not descend, making this choice even smarter than it already seems to be. 

For some, these new furnaces may pay for themselves in five years or less, but there are other issues as well. A new high efficiency furnace is a bouquet of flowers to the planet for all those extra trips in the car just to buy shampoo. Replacing inefficient carbon burning equipment is a manageable way to decrease your first-worldishness. We lucky, rich Amerikans use a huge percentage of the world’s resources and were only recently surpassed in environmental impact by China, a country about four times as populous as we. We owe it to the planet and to our children to take the $1,500, upgrade the noisy old furnace and pocket the savings. Aren’t we just too selfless? 

Before we’re done, let me share a few last thoughts regarding “condensing,” high-efficiency furnaces, since they’re not your father’s Oldsmobile. 

Condensing furnaces get their name from the nature of their exhaust systems. Natural gas furnaces all produce steam as the primary product of combustion, which is pretty nice when compared with oil or coal. It’s why we call it clean natural gas (CNG) as opposed to clean coal (which gets my vote for oxymoron of the decade). The steam that exhausts from a 95 percent furnace has been so closely shaved of heat (it’s almost all going to heat your house) that these flue gases may turn to liquid in the flue system and must be carefully managed. If this liquid is not well managed, it can wreak all sorts of havoc inside the furnace. So, modern condensing furnaces have several ways to deal with the water.  

First, the flues all tip downward, back toward the furnace so that they don’t end up dripping down the outside wall, eating the paint and staining the stucco (this water ends up being acidy and somewhat sulfurous). The water runs into a drain that may (if gravity allows) run outside to some point near the ground, where it can drain to soil. If gravity doesn’t allow, this water must be pumped away using a small reservoir and pump near the furnace. If furnaces are not installed level or have blockages, they may retain water, gurgle or become clogged. They may also rust through and require replacement in too short a time, turning the good deal bad. 

Therefore, when hiring an installer, don’t hire the cheap gal or guy. Hire someone who can intelligently discuss these issues. If you do have a furnace that gurgles, get it looked at. It may be drowning. 

Now I don’t feel any less critical of forced-air units than I did 10 minutes ago. Forced air is still clumsy. There’s no icing for that cake. That said, a high efficiency furnace can save a lot of money and a lot of carbon and that’s a good thing. I guess this makes it less stupid and I think that will make you pretty smart.