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Heat Pumps

wall unit with logo

Heat pumps offer an energy-efficient alternative to boilers, furnaces and window air conditioners. Some models provide cooling and others can both heat and cool. Like a refrigerator, heat pumps use electricity to move heat. Heat Pumps can also be added to hot water systems.   During the heating season, heat pumps move heat from the outdoors into the building; during the summer heat pumps provide A/C by moving heat from the building to the outside. Because they move heat rather than generate heat, heat pumps can provide much more energy than they consume. They use so little electricity combining a heat pump with solar electric photovoltaic modules is the perfect way to allow the sun's free energy to heat your home.

Efficiency Ratings & Cold Weather Operation

With a regular electric heat you get one unit of heat for each unit of electricity.  In Maine, on an annual average, Mitsubishi's new FH line of cold climate air source heat pumps will provide about 3.5 units of heat for each unit of electricity. In the cooling season the co-efficient of performance (COP) can be 4-5. Like all other products there are quality difference.  We like the Mitsubishi and Fujitsu lines.  LG and Daikin also make good products.  Both Mitsubishi and Fujitsu make many models and for the most part we use the ones with the highest efficiency.  These units can draw heat from the outside, and operate at full capacity, even when it is negative 13 degrees.  Fujitsu released their new RLS3H in March 2015.  They are rated to work to -15 and also has excellent HSPF efficiency ratings.  

Heating season efficiency is measured by HSPF.  SEER stands for seasonal energy efficiency rating and includes both heating and cooling seasons.  In both cases the higher the number the better.  Both Mitsubishi and Fujitsu have high rated units; heating seasonal performance factor (HSPF) at least 12 and SEER as high as 30.   Heat pumps do an excellent job at heating, cooling and summer dehumidification.

Heat pumps move heat using a refrigerant which it compresses and releases it into a gas.  They can gather heat from the outside even in very cold temperatures because the environmentally friendly R410A refrigerant actually boils at -55.3 degrees.

Our most popular product, air source mini-split ductless heat pumps

PV and Solar hot water on log homeHeat pump on log home

The majority of heat pumps we sell are Mitsubishi ductless mini splits.  They are filled with features that improve your comfort and indoor air quality. Their new FH line has some of the highest efficiency ratings of any manufacture plus they are rated to operate down to -13 degrees (experience shows they run to about -22).  These units are super efficient, energy star rated, and reliable. One of the biggest selling points is that both the indoor and outdoor units are very quiet. No more noisy, expensive to operate, window air conditioners. If you are noise sensitive we suggest you stop by our showroom and hear ours. The units are controlled with a remote and there is an optional wall thermostat. They have excellent filtration and actually improve the indoor air quality. You can program set backs and always wake, or come home to, a warm house but since they are so energy efficient when running on low to maintain temperature Efficiency Maine recommends you just leave it set 24/7.

When combined with a solar electric system using a heat pump is the ultimate way to provide free space heating and cooling with zero pollution. This home in Buxton plans to expand their PV system to cover the electric needs of their multi zone heat pump.  Line hide comes in 4 colors or the white can be painted to match the home.

Compared to a standard 15 year old tankless coil oil boiler the electric cost for the heat pump is like buying oil for less than $1.50 a gallon. Because these units are so energy efficient even with a jump in electric rates heat pumps will still be a bargain to operated.  If rates rise 20% from 15.5 cent to 19 cents compared to a tankless coil oil boiler it will be like buying oil for $1.70 a gallon.  If you are worried about rising electric rates you can always add solar electric panels and then the sun can provide free clean heat!


Multi zone mini splits with 1 condenser and up to 8 interior evaporators Split zone system

Mitsubishi split zone systems allow you to purchase one outdoor unit and run multiple indoor evaporators.  The outdoor unit can be located anywhere. Only small refrigerant, power, & drainage line is run and comes through the wall to the indoor unit. These are great for a larger home, or if rooms are separated by lots of walls and you need multiple indoor units.  Provided we can find a way to cost effectively run the copper on an outside wall, through the basement, or attic, you can use a multi zone outdoor unit. Sometimes the length or difficulty of running the refrigerant lines make using separate units more cost effective. The price difference between a multi zone unit and purchasing multiple separate units is not large.  The Multi zone units are available for 2-8 inside units. You can buy a larger outside compressor, say a 4 head, and install just 2 units to start.  

The new Mitsubishi Hyper-Heat multi zones have HSPF ratings of about 12 and work down to -13 degrees just like the single zones.   No other manufacture has a multi-zone product that can complete with these performance numbers. 

high efficiency FH15Our Harpswell client with a high efficiency new home tells us: It's -7 outside and the one FH15 is heating the entire house plus we have the door open to the poorly insulated sun room to dry the new plaster.

New Construction

If you are building a new high efficiency home a split zone heat pump may be the perfect, affordable, environmentally friendly, heating and cooling system.   We recommend you find a builder that truly understands how to build a tight, well insulated, energy efficient home.  It should be so tight you need a Heat recovery ventilator (HRV) to bring in fresh air.  When this is the case your daily heat loss is very low so even if we have temps < negative 20, and the unit shuts down, a few strips of electric baseboard or a plug in heater will keep you warm until the unit restarts.  

Mini splits are much less expensive than a high efficiency boiler and baseboard or radiant.  The exception is when you attempt to put a unit in many bedrooms.  We often suggest you place 1-2 heat pumps in the home and use some electric baseboard in the bedrooms in case the heat pumps cannot keep up.  This will satisfy building codes that may force a heat source in each room.  Since they are seldom used the additional operating expense would be less than installing additional interior evaporators.  If you put these baseboards on their own electric circuit it will be simple to monitor their electric draw if you ever have concerns about the cost of operation. If the home is well insulated summer heat gain will be minimal and A/C seldom necessary so even 2 heat pumps will do a good job of cooling.

The ideal time to get us involved is when you have the drawings ready so we can make suggestions before anything is set in stone.  

Geothermal, ground source heat pumps

Geothermal heat pumps work much the same way but they pull the heat from a well in the ground or a body of water such as a pond.   They are a bit more energy efficient since ground temps stay about 55 degrees year round.  The down side is the cost.  In October of 2013 Efficiency Maine set up a geothermal incentive.  50 incentives were reserved and the average cost was $40,000.  Even with a state and federal incentive a geothermal system is still very expensive.  Air-source heat pumps are popular because of their lower cost.  A unit for a large room runs about $3,100 before incentives.    No duct work is needed; only 2 small copper lines run from the outside compressor to the inside evaporator.  Installation generally takes one day. Plus the new Mitsubishi FH09 has a COP of 3.8 which equals the efficiency of many geothermal heat pumps. 

Heat pumps integrated into hot water tanks


Heat pumps are now also being installed on hot water tanks. 

They can save a great deal on domestic hot water costs.

For more information see our high efficiency hot water tank page or watch this video from Efficiency Maine



Whole house ducted heat pumps

If you have a forced hot air system there are new whole house dual source furnaces that have a built in heat pump.  Most are not as efficient and do not work to super low temps like the mini splits but they will make a significant cut in your energy bill.  The exception is the Bryant Extreme.  The current model only works with Carrier furnaces but an upgrade is expected in late 2014 where it will integrate with any manufactures unit.  The Bryant Extreme can actually run down to -20 just like the mini splits and has similar energy efficiency. While the outdoor temp is in range the furnace runs in heat pump mode saving significant money.   When it gets too cold outside it will automatically switch to propane and run like a normal, efficient, furnace.

Incentives and where to learn more about heat pumps

We are huge fans of Home Power magazine.  There is no better source to learn about energy efficiency, solar, and green living.  They cover DIY projects as well as times when you need to bring in the pro's.  A subscription will be one of the best investments you will ever make.  If you get the online option you can view all the previous issues and do searches for topics that interest you.  About the only down side is this is a national publication so sometimes what they talk about does not work well with our cold winters.  They have an excellent article on Heat pumps.  

Mitsubishi heat pumps

Fujitsu heat pumps 

$500 residential heat pump incentive from Efficiency Maine.  We are experts at the incentive programs and know how to combine this rebate with other programs to maximize your rebate.    Commercial mini split heat pump incentive are larger because of the higher run time, and thus more energy savings.  Businesses get $1000 for single zone units and up to $2,200 for mulit zone units. There are also significant rebates for multi-family apartments.


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