Retrofits

Benefits

Did you know that the average single-family Juneau house spends close to $2,000 to heat their space and hot water?  That’s 80% of the house’s total energy costs! Because heat pumps are so much more efficient than standard heating systems, the average Juneau homeowner can reduce their space heating costs by more than 40% by switching to heat pumps.

Retrofitting your home with heat pumps can allow you to minimize your home’s carbon emissions. Because Juneau’s electricity is primarily provided by hydropower, the electricity powering your heat pump produces no carbon emissions. Heating with fossil fuels depends upon a long, sometimes convoluted supply chain. Fuel prices and reserves are usually controlled by forces and events that we are unable to predict or control. Juneau’s hydropower is produced locally, and utility pricing is subject to regulatory approval. In addition, converting from electric resistance heat to a heat pump helps conserve our carbon-free hydropower resource. Excess hydropower can also be used to reduce CO2 emissions from diesel generators on cruise ships and at Greens Creek Mine.

Besides providing less expensive heat, household cash flow can be better managed using a heat pump rather than fossil fuels. A heating oil tank is generally only filled once or twice a year, and that can be a big expense to cover all at once. Especially if the price of oil has recently jumped! Heat pumps are powered by electricity so the cost is payed monthly in your utility bill. It needs to be noted that heat pumps do use electricity, so you may see a higher electric bill; however, if you currently heat with electric baseboard, your heating bill will go down!

Lastly, heat pumps can also cool your home. With warmer summers an inevitable part of our future, adding cooling capacity will likely be an unexpected convenience.

Considerations

Electrical System

Heat pumps do require electricity to power them. A heat pump will require a dedicated electrical circuit, typically 240 volts and at least 20 amps (possibly more). The circuit will need to be run where the outdoor compressor unit will be located, and a disconnect switch will need to be installed adjacent to the compressor. For retrofits this usually involves running electrical conduit from a breaker panel to the compressor. This is work for a licensed electrician, and will require a building permit.

Homes in Juneau can run into two issues with their electrical service:

  1. The main electrical service coming from the utility may not be able to support the added electrical load created by the heat pump. The service wiring or other components may be too small. This is typically only a problem with older homes, but a licensed electrician should evaluate your service.
  2. Each electrical circuit needs to be protected by a circuit breaker or fuse panel. It’s not uncommon for a panel to be completely full of breakers with no room for another breaker for the heat pump circuit. This may require the consolidation of existing breakers, or possibly the installation of an electrical subpanel. In either case, this is work for a licensed electrician. (Pro tip: If you’re going to modify your breaker panel, think about any other electrical loads you may add in the future. This is a great time to make panel space for that electric vehicle charger that your next car might need.)
  3. Here are some examples of the types of breaker panel that you are likely to find in your home.
Upfront Cost

Upfront costs vary considerably based on many factors unique to every home.  We tend to estimate $4,000 for a simple single-head installation (parts and labor) plus $600-$1500 for the electrical work.  Complex installations of multi-head installations cost more, of course.  There is not a huge price difference between the different unit output ratings.

Some handy homeowners want to reduce costs by performing the work themselves. Alaska Heat Smart does not recommend that anyone but a licensed refrigeration technician install the actual heat pump. However, there may be other aspects of the project that you could do yourself. This should be discussed with any installation contractors ahead of time. Alaska Heat Smart may be able to suggest some opportunities for you to consider.

Financing may be available to reduce the upfront costs of an installation. With the low interest rates and flexible terms available, some homes can save enough money in reduced energy costs to pay for the entire financing costs. Tax credits and other grants are also available depending on your individual circumstances.

Legacy Heating System

As a general matter, Alaska Heat Smart encourages homeowners to consider retaining their existing systems if possible.  This provides a redundant heating system in the event of the failure of one of them (always prudent in Alaska); it provides flexibility in configuring your system since it doesn’t have to achieve 100% coverage of your house; and it reduces the risk of undersizing your heat pump because you already have a proven system as a backup.  If you decide to pursue a whole-house replacement of your heating system, we strongly recommend that you consult with a heating professional to ensure that your new system meets relevant building codes and will keep you warm. 

Alaska Heat Smart can make suggestions for you to consider regarding your existing system. Learn more about our free Home Assessment program here.

Recommendations Based on Your Existing Heat System

Toyo or Monitor Stove

Generally replacing a Monitor or Toyo stove is a simple heat pump retrofit project.  You’re already familiar with how your house is heated with that single point appliance, so replacing it with a single-head heat pump is a straight-forward process.  Bear in mind that your oil-fired heater probably has a higher heat output rating than a single-head heat pump (30,000+ Btu vs ~15,000 Btu), so if your oil heater is struggling to keep you warm, you might need to consider a multi-port heat pump.  One strategy, if space allows, is to install the heat pump while retaining the oil stove for the first heating season to see if the heat pump is up to the job.

Forced Air Furnaces

There are a couple common options for retrofitting a heat pump into a house with a forced-air furnace.  

You can retain the furnace as a supplemental heater and install heat pump heads in discrete locations in the house.  You may need to relocate your furnace thermostat in some cases so it doesn’t get a ‘false reading’ in a room already being heated by the heat pump – you’ll want the thermostat in the same area that will be heated principally by the furnace.  

You can also install a ducted indoor heat pump unit that mounts in the existing furnace ducts and uses them to distribute the heat throughout the house.  This option should be discussed with a heating professional to see if your furnace is a good candidate for that.

Hydronic Boilers

An advantage with hydronic boiler systems is that they deliver heat to every room in your house. They also allow the system to be segregated into separate heating zones that provide heat to separate areas of the house.  It is often challenging/expensive to retrofit a ductless heat pump to serve a comparable function.  

If your oil boiler is still functional you can retain it to act as a backup/supplemental system, or to provide heat to areas not served.  If your boiler is reaching the end of its service life, or if you want to transition off of oil heat entirely, replacing your oil boiler with an electric boiler may be a good option.  That allows you to still take advantage of your house’s existing heat distribution infrastructure, while at the same time eliminating the use of oil.  Electric boilers are generally less expensive to purchase than oil boilers and require little maintenance.  They’re also smaller and don’t require a flue (chimney).  They do, however, require a substantial electrical service, so consult with an electrician before pursuing that option.

With either an electric or oil boiler, the cost of heat is higher.  But because your heat pump will be carrying a substantial portion of your house’s heating load, that actual amount of energy you use from those sources on an annual basis may be very modest.

One warning:  Bear in mind that the hydronic distribution piping often runs around the perimeter walls, and even in the unheated crawlspace.  If the heat pump is providing most of the heat and the hydronic system isn’t in use during very cold weather, the pipes could freeze and burst, and cause expensive water damage.  Consult with a heating profession about strategies to mitigate that risk, such as adding antifreeze to your hydronic system, adding heat trace to the piping, or replacing vulnerable copper piping with PEX or another less susceptible material.     

Wood Stove

A heat pump can be a good complement to a wood stove, and it’s a lot cleaner and more convenient!  People that burn wood regularly find that they don’t burn as frequently during mild weather (when the house can be overheated by the stove), and they don’t have to fire up first thing in the morning because the heat pump already has the house warm. Keep in mind that many wood stoves are capable of producing in excess of 50,000 Btu.  If your house requires that much heat during cold weather, you’ll need a large, multi-port heat pump to provide it. One other thing to be aware of is that ductless heat pumps deliver all of their heat through convection (air transfer), which has a different ‘heat quality’ than the radiant heat from a wood stove.  

Pellet Stove

A pellet stove functions very similarly to an oil stove like a Toyo or Monitor.  It delivers heat to a discrete location in the house.  If a pellet stove is proving acceptable, a single-head heat pump in the same location may be a viable replacement.  As with the oil stoves, a pellet stove can often produce much more heat than a single heat pump, so before removing the pellet stove is may be prudent to retain it during the first year to ensure that your heat pump is up to the task.