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

What are the options

What Fuel? Chips? Cordwood? Pellets?

Location Outdoor Indoor

Thermal Storage or Not

Furnace or Boiler

Understanding the Numbers

Comparison of Test Methods for Hydronic Heaters

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 303- 5 PM Emissions lb/mmbtu M28WHH PM Emissions EN 303-5 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%

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.

Lessons Learned

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

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