1. Wood-Fired Central Heating
Residential Wood Smoke Workshop
March 7, 2018

2. What are the options

3. What Fuel?
Chips?
Cordwood?
Pellets?

4. Location
Outdoor
Indoor

5. Thermal Storage or Not

6. Furnace or Boiler

7. Understanding the Numbers

8. Comparison of Test Methods for Hydronic Heaters

9. What the numbers mean Understand the numbers
Cordwood units have same issues as wood stoves and need revision
Different test methods yield different results
Device
EN PM Emissions
lb/mmbtu
M28WHH
PM Emissions
EN Efficiency
M28WHH Efficiency
Unit 1
0.03
0.08 85 70
Unit 2
0.04
0.07 73
Unit 3 86 79
Unit 4
0.02 75
Unit 5
0.06
81*
Unit 6 87
86*
SAME UNIT/Different Test
EN303-5
EPA PTS
Emissions lb/mmBtu
0.06
0.18
Efficiency
86%
70%

10. Which unit is better? Unit 1 Unit 2 100% load output 90,000 99,737
Emissions lb/MMBtu
.04
.05
Efficiency
86%
82.5%
25-50% load output
40,480
42,923
.06
82%
91.2%*
15-24% load output
19,800
22,517
75%
77%
<15% load output
12,600
NO TEST
.08
64%
Unit 1 average
0.07 lb/MMBtu; 73% eff.
Unit 2 average
0.06 lb/MMBtu; 81% eff.

11. Lessons Learned

12. Central Heating Change-out Programs Lessons Learned
Change-outs are more difficult to get right
Sizing
System Integration
Fuel storage requirement for wood pellets – wood pellets off gas CO
Costs vary widely
Analysis of actual costs for change-outs show wide range of costs – equipment and installation

13. Energy Office Incentive Programs
State Energy offices are offering rebates of 5-20K for residential units
Typical incentive needed to move units is ~50% of costs.
Even with installed costs staying flat and increased incentive levels (up to 20K) the number of installations has been steadily decreasing.
Likely due to low cost of natural gas and home heating oil.
Incentivized Residential Pellet Boilers
2014
2015
2016
2017 MA NA 38 10 4 ME
251
181 81 43 NH 63 41
28* 18 NY 9 12 VT 36 25 17
*NH had to increase incentive from 5K to 10K to move units, however the following year #s continued to decrease