Going Green Efficiently and Economically

What is a Mini-Split Heat Pump? A MSHP is an energy saving

supplemental heating source

Mini-splits use electricity to move heat from outdoor to indoor by the refrigeration process.

Heats or cools on demand

Ductless (less energy lost)

Easy and inexpensive installation and maintenance

Allows for zoning with multiple units

Unobtrusivehttp://www.fujitsugeneral.com/how_ms_works.htm

A Mini Split Heat Pump can help you…

Go Green – Heat Pumps can reduce your carbon footprint because of their high degree of efficiency.

Save Money – Heat Pumps can reduce the cost of heating/cooling your home year round by supplementing your current heat source.

Save energy - Heat pumps transfer the heat energy in the outside air into your home.

Basic Energy Terms Watt (W)

Basic unit of power Mostly for electricity Typical light bulb in a lamp takes 60 Watts

Kilo Watt Hour (kWh) Measurement of electricity that utility companies deal in. Thousands of Watts used in an hour

Btu British Thermal Unit Heat energy unit Amount of energy used to raise 1 lb. of water 1º F 138,095 BTU in one gallon of heating oil

Basic Energy Terms

1 W = 3.413 BTU/hour A 60W light bulb gives off 60W of heat or the equivalent of

204 BTU/hour (in addition to the light produced).

Mbtu Mega Btu, or one million BTU’s

Common unit for comparing energy prices

COP Coefficient of Performance

Heat energy produced/unit of input energy

Household Energy UseAn average of 82% of a household’s energy use in New England is space and water heating.

http://www.maine.gov/oeis/docs/2002_1_15_ReduceHousholdEnergyby25.pdf pg 10.

Ways Mainers Heat their Homes

http://www.maine.gov/oeis/docs/2002_1_15_ReduceHousholdEnergyby25.pdf pg.11

Maine predominantly uses oil burning furnaces for heating.The cost of oil shows no sign of declining.

Our dependency on oil is money that flees our state’s economy.

How do Mini-Split Heat PumpsAffect Energy Usage?

Mini-splits reduce the consumption of fossil fuels in your existing heat source.

They use the heat from outdoor to warm homes in temperatures as low as 5ºF.

Conventional systems used when colder

http://brooklyn-newyork.olx.com/

Traditional Oil Heaters

Energy Cost

$2.66/gallon: $21.11/Mbtu

An average Maine home (2000 sq. ft.) uses 144 Mbtu/year.

Oil cost $3039.84.

(about 1,143 gal/year)

Installation Cost

New system costs $1500-$3500

http://www.alternative-heating.com/heating-equipment.html

Environmental Impact

Burning #2 heating oil

73.15 kg CO2/MBtu burned.

Annual pollution: 10,533 kg CO2

Maintenance

Average annual upkeep: $100/year.

Traditional Oil Heaters

Solar Thermal Water Heating Energy

Solar Energy is free 2 sq. meter solartherm

16382Btu/day, or 5.98 MBtu/year

Compare to oil cost: Saves $135.62

Installation Cost Cost $6,500 (2 m2 Panel, 80g Solar Water

tank, install cost) 30% Federal tax credit $1000 Maine State rebate

Simple Payback $6500/($135.62/year) = 47.92 years

http://www.sunstuffenergy.com/howWorks.htm

http://securedb.fsec.ucf.edu/srcc/sys_detail?srcc_id=2004001A

Residential Wind Turbines Energy Cost

Free, can potentially sell power back into the grid

Cost:

$16500

30% federal tax credit

$2000 Maine rebate

Cold Climate Heat Pumps Energy Cost

Electrically powered, costs $0.16/kWh

COP of 2 at -30ºF

COP of 3.5 at 50ºF

Installation Costs

$10,000 - $14,000

Must install ductwork

Up to $1600 tax credit in Maine

http://home.howstuffworks.com/home-improvement/heating-and-cooling/heat-pump1.htm

http://www.energyideas.org/documents/Factsheets/PTR/AcadiaHeatPump.pdf

http://www.blueplanetgreenliving.com/2010/03/03/hallowell-acadia-is-revolutionizing-the-heating-industry/

Mini Split Heat Pumps

Energy Cost Electrically powered, costs

$0.16/kWh

Installation Cost ~ $3000

30% federal tax credit

Efficiency Maine: $250 rebate

Parameters Minimum outside temp 5ºF

Heat Pump BenefitsTwo important efficiency points

Energy Efficiency

Cost Efficiency

Energy Efficiency Assume an oil burner is 90% efficient, which is reasonable

for new, high efficiency oil furnaces.

For 2,000 BTU of oil input there is 1,800 BTU of heat output.

Assuming a 50% efficient power plant and 6.7% transmission losses.

2000 BTU of fuel burned at the plant yields: 1000 BTU of electric energy will be sent to the grid 933 BTU available after transmission

Heat pump is more energy efficient if COP > 1.93 COP = heat output/power input i.e. 1,800 BTU/933 BTU = 1.93

Economic Efficiency Oil costs $21.11/MBtu in its raw form.

In a 90% efficient oil burning furnace:

1 Mbtu of home heat costs $23.45

Electrical heat costs approx. $0.16/kWh in Maine.

If using electric coils to heat:

1 Mbtu of home heat costs $46.88

Heat pumps move heat energy from outside using elec.

$46.88/$23.45 = 1.999

For a heat pump to save money, COP > 1.999

Heat Pump Temperature Efficiencies Heat Pumps have the highest COP milder days

Assuming a desired room temperature of 70ºF: When it is 30ºF outside, COP= 3.71

When it is 5ºF outside, COP = 2.82

Even when it is extremely cold, a heat pump is more efficient than an oil system. However as temperature decreases, the total output also

decreases.

While still more efficient than oil Compressor capacity is low at lower temps

Use in addition to existing heating system

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Outdoor Temp

Mini-Split COP vs Outdoor Temp

60 deg F

65 deg F

70 deg F

75 deg F

Indoor Temp

What is a Heat Pump? A heat pump consumes electrical energy to move heat

from one location to another.

The four major components are a compressor, a condenser, an expansion valve, and an evaporator.

Refrigerant is pumped through the cycle to absorb/release thermal energy through the evaporation/condensing of the coolant.

http://www.thefullwiki.org/Heat_pump

The Compressor The compressor starts the cycle by increasing pressure

on the refrigerant by using shaft work.

Vapor coolant enters the compressor heads at a low pressure, low temp liquid and leaves as a high pressure, high temp liquid.

This heat is absorbed later on in the cycle.

(Carlyle O6E series Compressor)

http://www.carlylecompressor.com/corp/details/0,2938,CLI1_DIV24_ETI1223,00.html

The Condenser The condenser rejects thermal energy out of the

system by cooling the refrigerant to change states.

High temperature/pressure vapor coolant enters.

High temperature/pressure liquid coolant exits.

The latent heat released to the condenser from the change in state of the refrigerant is transferred to the condenser coolant.

http://tommyji.en.made-in-china.com/offer/AblEMBmdhtrO/Sell-Aluminium-Evaporator-Copper-Evaporator-Copper-Condenser-.html

The Expansion Valve The expansion valve restricts the flow of the high

temp/pressure liquid which forces a pressure drop.

The drop in pressure subsequently causes a drop in temperature.

The refrigerant exits as a low temperature, low pressure liquid.

http://www.hiwtc.com/products/electronic-expansion-valve-784-99.htm

The Evaporator The evaporator absorbs heat from outside the system

and warms the refrigerant to change state.

Low temperature, low pressure liquid coolant enters.

Low temperature, low pressure vapor coolant exits.

http://www.diytrade.com/china/4/products/2715158/A_C_Evaporator.html

Putting It All Together: Cooling Cycle1. Hot Coolant leaves compressor and dumps heat to outside air.2. Low temp Coolant enters indoor unit and absorbs heat.

Heating Cycle1. Hot Coolant enters home and dumps heat to inside air.2. Low temp coolant picks up heat from outside air.

http://www.helmsway.com/heat_pump.htm

Examples of Heat Pump Style Systems

Window Unit Air Conditioners

Move heat from inside an overly warm house to outside its walls

Refrigerators

Uses heat pump cycle to keep food cool

Mini-Split Heat Pumps

Can both heat/cool a home by a reversing valve allowing flow in both directions.

Air Conditioning

Refrigerator

http://china-heatpipe.net/heatpipe04/08/2008-4-24/The_Vapor-Compression_Refrigeration_Cycle.htm

Mini-Split Heat Pump

http://www.fujitsugeneral.com/how_ms_works.htm

Efficiency of Heat Pumps Efficiency of a heat pump is often expressed in terms

of the system’s COP (coefficient of performance).

Refrigerator: “energy moved” is the energy taken from the refrigerated space.

Heater: “energy moved” is the energy rejected into the already warm space