What are the Health Effects of Heating with Wood?

What are the Health Effects of Heating with Wood?

This graph compares the typical annual PM emissions from different heating fuels and equipment.
Comparative typical annual PM emissions from different heating fuels and equipment.

A  pellet boiler is the real comparison to oil and gas heating.

The image we have in our minds of a dirty, sooty wood stove from before 1988 is obsolete. Modern wood and pellet stoves have gone from an annual PM of 4.6 to 1.4, and modern pellet stoves are even lower, at 0.49 PM annually.

That’s still way higher than a modern pellet boiler, which, at 0.032 PM, is not all that different from the particulate emissions from oil (0.013) and even propane (0.0083) boilers. This is a small difference given the much more consequential comparison of heating with a renewable rather than a fossil fuel option.

There is no free lunch when it comes to heating our homes and businesses.

Just like cars, trucks, airplanes, and cruise ships, heating emissions are not good for human health. However, consider this: emissions from wood heating can be an irritant in the lungs, but emissions from fossil fuels are a known carcinogen.

Heat Loss

The two variables of of heat loss are a) geographic location, and b) building performance. Together they will determine the quantity of heat needed to maintain comfort.

Geographic location drives the building's “design day." Your design day is the difference in temperature between the inside and outside of your house on the theoretical coldest day of the year; so in the northeast we calculate a day that is -10ºf outside and comfortable 68ºf inside. This is referred to as the “delta-T” value. A typical delta-T for the northeast is 78º.

Building performance is the big one because there’s nothing we can do about geographic location. Today we can build a really tight thermal envelope, but most of our heating pollution comes from the millions of homes built over the last 100-150 years. We are getting better at buttoning-up those old buildings with insulation and weather sealing but weatherization is still  never going to be enough to overcome the heat loss from a 78º delta-T. That means we need heating systems that can quickly put a whole lot of heat back into those old houses on the days that are really cold.