heating + cooling with heat pumps.

: get pumped about heat pumps! 

Heat Pumps : Efficient Technology to heat (or cool) your home or building

The Basics. 

A heat pump is a mechanical HVAC system that uses a small amount of electricity to move heat from one location to another instead of using combustion energy to directly heat or cool air or water. During colder months, heat pumps draw heat from the environment and move it indoors to heat your home. During warmer months, they run in reverse to provide space cooling like a conventional air-conditioner. 
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​There are 3 main types of heat pump systems classified by the medium through which they transfer heat: 
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(1) Air-Source Heat Pump (ASHP) - these are the most common
(2) Ground-source (or geothermal) heat pumps
​(3) Hydronic systems with heat pump water heaters 

Scroll down for the details of each of these!​

Efficiency. 

Air source heat pumps are far more efficient than traditional heating systems
because they are "heat-movers" rather than "heat-makers"; i.e. heat pumps don't spend extra energy on heat generation. Today's heat pump technology can reduce electricity use for heating by ~50% compared to electric resistance heating and can transfer 300% more energy than it consumes. In contrast, a high-efficiency gas furnace is about 95% efficient. 

This often equates to lower energy bills when switching from propane, oil, and electric-resistance systems - though it's not always true that switching from methane gas to electric saves money, at least today. Lots more on all this at Energy.gov. 

In a nutshell, although they can be expensive to purchase (check out all the tax credits and rebates!) they pay off in long-term savings and cleaner air!​

Additional Resources

• A helpful article from Canary Media: ​A beginners guide to the different types of heat pumps.  
• Here's a Montana-specific factsheet from RMI about heat pumps in cold climates.

Ready Ted & Diane's Story

Ted & Diane decided to go all electric when their aging furnace gave up. They have both a mini split and ducted air-source heat pump. Read their story here.

Health and Safety. 

Heat pumps are so much more than just a heating and cooling device. Unlike traditional heating methods, heat pumps cleanse the air as they work. The filtration system maintains good indoor air quality - an important part of reducing the number of harmful pathogens in the air. Unlike traditional methane gas boilers and furnaces, heat pumps don't leak, burn incompletely, or rely on potentially dangerous faulty gas lines as their energy source. 

Environment. 

Heat pump technology is essential to decarbonizing the built environment.
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Because heat pumps are electric and don't rely on fossil-fuel combustion to operate, the on-site GHG emissions are zero. As more and more electricity is sourced from renewable energy in Montana (like solar and wind) off-site emission savings are estimated to be around 70% compared to ​fossil-fuel based systems. Choosing a heat pump over traditional systems also makes  your home “net zero ready” as our electrical grid moves from fossil fuel to lower C02-producing sources. 

Key Benefits: 

1. Technologically mature:  work darn well in cold climates and getting better every year.
2. Easy to install in new construction. Possible to retrofit in existing buildings but not always easy! 
3. Versatile & Efficient: Het pumps can both heat and cool buildings more efficiently than traditional systems.
4. ​Greater comfort: heat pumps heat and cool      consistently, which means less hot/cold spots.
5. Long-term savings: usually lower annual utility bills (though not always the case when going from methane gas to electricity, at least at current rates).
6. Improved health and safety: no gas lines + ​improved indoor air quality. 
7. ​Zero on-site greenhouse gas emissions!​

How heat pumps work. Graphic from Department of Energy.

Cold Weather Effectiveness. 

Heat pumps do work in cold climates!  The new generation of cold climate air source heat pumps operate efficiently down to 0F or even colder, but as temperatures decrease, so does the ease with which they can extract heat from the air. At -10 F for example, the will generally still work, but they will cost more to operate. Most systems in Montana include backup heat - radiant heat, methane gas, wood or pellet! Here's a great piece from Yale Climate Connections.

Some folks chose to keep their old system (ie. a gas furnace) and only use it when the temps drop below 0 F. It's also possible to use a pellet stove or as a backup. Other advances in heat pump controls have allowed for a more seamless integration of backup electric resistance systems, which provide an extra layer of security in extremely cold climates. (RMI) 

Cooling, too. ​

As Montana summers heat up, more and more folks are looking for ways to cool homes and businesses. Most of us do pretty well much or all of the summer with opening windows at night and closing everything down as the temps rise. But sometimes this is just not enough or sometimes it's too smoky.

​With a heat pump you don’t need to install separate systems for heating and cooling. You can rely on one unit for every season.  
(SMO Energy)  

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Heat Pumps: Main Types

*A note on cost: The exact cost of a new heat pump will depend on your current heating and cooling system setup and what work must be completed before the heat pump can be installed. What we offer below does NOT include tax credits and rebates that are part of the Inflation Reduction Act or come from NorthWestern Energy, Missoula Electric Co-op, or other rebates.

01

Ductless (mini-split) System

 : an air-source system that uses small, indoor wall-mounted units (called mini-splits) connected to one outdoor compressor to distribute and handle air

• ​Cost: For a single-zone system, you could expect to pay $2,500-$5,000. A 4 zone (rooms) ductless mini-split heat pump system could cost anywhere from $8,500 to $15,000. The cost savings from various zone control options and the lack of required additional ductwork can be immense. Higher costs are driven by the use of more internal heads (the units mounted inside) and more powerful heat pumps.
• Installation: Minimally intrusive, very flexible installation options. Indoor units can be installed on the floor, the wall, or the ceiling.
• Equipment: (depends on installation options) Split-ductless heat pumps have two primary units: an outdoor compressor/condenser and one to four indoor air handlers.

02

Centrally-Ducted Heat Pump 

 : an air-source system that relies on a single air-handling unit that redirects conditioned air throughout your home via ductwork

• ​Cost: Central heat pump systems cost between $12,000 and $20,000. For central systems, the size of the total living space that the system is heating and cooling will often be the primary driver of project costs.
• Installation: Less flexible to install than mini-splits (require ductwork), larger central indoor unit requires more installation space, often installed in basement/mechanical room.
• Equipment: Single standard-split air-handling unit, supply ductwork.

03

Ground-Source (Geothermal) Heat Pump

: an electrically powered cooling and heating system that moves fluid through long loops of pipe (either direct buried or in drilled wells) to transmit heat/cooling between the earth and the building 

• Cost: Expensive relative to other heat pump options due to land excavation costs. On average, a homeowner can expect to invest about $12,000 to $30,000. Depending on factors such as climate, soil conditions, the system features you choose, and available financing and incentives, you may recoup your initial investment in two to 10 years through lower utility bills.
• Installation: Stringent site requirements; geothermal systems are installed underground or in water, so the installation process itself can be costly, lengthy and can require specific soil conditions on site .
• Equipment: (depends on system type) Geothermal water-loop piping (horizontal or vertical), heat exchanger, connect to ductwork/air handler.
• Maintenance: Typically, the design of the system results in very little required maintenance. As long as it is installed properly, a geothermal system can last for a very long time. If maintenance is required, it can be a bigger deal - as it may require additional excavation. 

04

Hydronic Heating Systems: Heat Pump Water Heater (HPWH)

:​ a heat pump can also be used to heat water as a combination water-heating and space-conditioning system

• Complexity: First a note: Using a HPWH hydronic systems is still new and here in Missoula there are few contractors retrofitting heating systems that use boilers with fully "hydronic" HPWHs. It's easier (of course) to design a new system with these. Check out Jeremy's system as an example. 
• Cost: The HPWH tanks typically have higher initial costs than conventional storage water heaters; a 50-gallon heat pump water heater goes for ~ $1,100. However, compared to conventional systems, they offer a savings of around $3,400 over the life of a typical HPWH. 
• Installation: Heat pump water heaters require installation in locations that remain in the 40º–90ºF (4.4º–32.2ºC) range year-round and provide at least 1,000 cubic feet (28.3 cubic meters) of air space around the water heater. Air passing over the evaporator can be exhausted to the room or outdoors. Installing them in a space with excess heat, such as a furnace room, will increase their efficiency.
• Equipment: Tall, cylindrical indoor water heater tank connected to the heating system (radiators, coils in the floor, etc.).​

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