Environmentally-Friendly-Heating-Cooling

Environmentally Friendly Heating and Cooling 17 June 2021

Bob Zogg — founding member of Heatsmart AllianceBobzogg@luxsci.net

  • Accelerating Heat Pumps
  • HeatSmart Alliance:
    • Mission: reduce greenhouse gas emissions by accelerating the adoption of energy-efficient heat pumps in MA homes and buildings
    • Applications: home heating and cooling, water heating
    • All volunteer organization
    • 24 MA communities
    • Approach: educate / coach / collaborate
  • New England Energy Use
    • 56% trans
    • Resi 30%
    • Indu 13%
    • Commercial 25%
  • Average home energy use
    • Heating and cooling is 61%
  • Heat Pump IS ready for cold clients
  • Existing Central Ductwork
    • Central heat pumps
    • Ground Source (aka geothermal) Heat Pumps
  • No ductwork
    • Ductless mini-split systems (single and multi-zone)
  • Water heating
    • Heat pump water heaters
    • Aka Hybrid Water Heaters
  • Emissions Reduction in metric tons of CO2 per 2000 sq ft home
    • Ground source has the lowest emissions 1
    • Air source heat pump 1.5
    • Natural gas 3.5
    • Propane 3.75
    • Baseboard electric 4.5
    • Fuel oil 5.2
  • Heat pump emissions go to practically zero if your electricity is renewable
  • MA Clean Energy Plan for 2030
    • Goal: heat pumps across 1 million house holds (out of total of 2.7 million)
  • 4 challenges to large-scale residential conversion
    • No sex appeal compared to solar, Tesla, or HVAC
    • Which comes first? Air sealing/insulation versus heat pump
    • Installers assume low cost over carbon savings
      • May try to match existing system type
      • May encourage you to retain fossil system
      • May set swap-over from heat pump to backup cautiously high
      • Heat pumps can heat well insulated/air-sealed MA homes w/out supplemental heat
    • Natural gas is really cheap right now
  • 4 actions to accelerate heat pumps
    • Installation
      • Convert to heat pump when heating or cooling is aging (over 15 years old)
        • Don’t wait until system fails and replacement becomes urgent
      • Adding AC to a home that doesn’t have it yet
        • Heat pumps do both heating and cooling
      • Planning an addition, renovation, or new home
    • Become a volunteer coach — help friends, neighbors
      • Replacing heating/cooling is time-consuming and intimidating
      • Coaching works
      • You can become a coach at heatsmartalliance website
    • Ban fossil fuels in new construction (home rule petition)
      • Passed in concord, Lexington, Arlington, acton might do it
    • Advocate for favorable policy
      • MA
        • DOER to set GHG goals for Mass Save by 7/15/2021
          • More aggressive weatherization measures and eliminate incentives for fossil fuel
        • Simplify incentive programs (too many agencies involved)
        • Cap and trade heating fuel emissions
      • Federal
        • Restore 30% tax credit for ground source which sunsets by 2023
          • Now at 26% in 2021
  • Peter’s testimonial on ductless mini-splits
    • Installs were around $4k
    • Floor mounted until by Halcyon Single Mini Split Systems
    • Compact cassette mini-split for 2nd floor (ceiling based)
    • The external unit should be a couple of feet off the ground
    • Floor until 100% of heat down to 30 degrees
    • Boiler kicks in below 30 (especially for far rooms)
    • 2nd floor — very good heat even in sub-zero
    • Downsides:
      • Installers oversize and reduce efficiency
      • 1 recommendation 1 head per room (100% coverage but kills efficiency)
      • Multiple needed for large foot print, raising costs
      • Raise units off ground to avoid getting buried in snow
      • Not as simple as boilers
      • Power outage = no heat if no backup
    • Benefits
      • Not setbacks! Now waking at 55f, constant temperature is more efficient
      • 95% effective cooling at low price
      • 100% heat on 2nd story outside of below zero temps
      • Our house had baseboard electric heat and boiler installer recommended heat pump for 2nd floor instead of renovating radiators
      • 1 day installation, very little demolition
    • Costs
      • Installs were about $4000 each in 2018
      • Cooling bill estimated at $50 per months
      • Difficult to discern heating cost but for reference we’ve used an average of 350 gallons oil annually since 2017 install
      • Monthly energy costs $250 — heat, hot water, cooling, cooking, family of 4
  • Trevor’s testimonial
    • Our first ground source — single 4 ton w/ electric backup in 2002 in Nova Scotia
    • 2nd install (in Harvard) - 2 four ton ground source heat pumps
      • 100% of heat from heat pumps for last 3.5 years (keeping house at 74 in winter, 76 in summer)
      • Very quiet
    • 6 foot deep trench that has 4 200’ bore holes that follow the driveway
    • Water and ethanol circulates in loop (anti-freeze)
    • Ground loop circulation pumps
    • 2 pumps (load sharing or primary/backup?)
    • From pumps, the heated water goes to an accumulator tank
    • Main control unit with sensors for outdoor temperature and tank
    • Pumps into in floor radiant heat