Inverter Heat Pump

My wife and I recently had an inverter heat pump/gas furnace back-up system installed in our home. Like many people we captured some images of the installation process for posterity. This article discusses some of the factors we considered before making our purchase decision.

Disclosure Statement.

It is important to state upfront that my wife and I did not receive any kind of compensation to produce this article and share our experience with readers. Since many people are concerned about climate change, as well as the rising cost of utilities, we thought this article about our deliberations and decision may be of benefit to many of our readers.

NOTE: Click on images to enlarge. or

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 35 mm, efov 70 mm, f/8, -0.7 EV, 1/320, ISO-1000

Like many homeowners my wife and I were using a traditional HVAC set up of a separate air conditioner unit for cooling, and a high efficiency gas furnace for heating.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 31 mm, efov 62 mm, f/4, -0.7 EV, 1/40, ISO-400

Our air conditioner was over 23 years old and the refrigerant it used was non-current. That meant that it was no longer legal to repair it should our unit have a refrigerant leak. Our furnace was over 18 years old and likely needed to be replaced over the next few years. The availability of parts and the potential of an expensive, major component failure with the furnace, were factors that lead us to investigate an HVAC system upgrade.

We had been discussing the possible shift to a heat pump based system during the past couple of years, and I had been doing some research in this regard. This type of decision is complex, and is best done after much forethought and investigation. Waiting for an AC unit or a furnace to fail, then rushing into a heat pump purchase may be a recipe for disaster.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 23 mm, efov 46 mm, f/4, -0.7 EV, 1/320, ISO-125

I’d recommend being very selective with your sources of information as unfortunately there is a lot of misinformation on the internet. We looked at some federal government information, as well as that from provinces like British Columbia and Manitoba.

I found a number of helpful websites including one that referenced some information from Natural Resources Canada, and a YouTube video that had some real-life research data done in Maine.

If you are located in a colder climate you may be wondering if a heat pump can heat your home. The quick answer to that is yes… there likely is an appropriate heat pump solution for you. Depending on your local climate your system may need to include a back-up gas furnace or an air handler. Our system has a communicating back-up gas furnace.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 14 mm, efov 28 mm, f/4, 1/100, ISO-2000

Learning about heat pump types and suitability.

There is a steep learning curve to climb when considering which heat pump is best suited to your particular situation… or even if it makes sense to install one at all.

Whether it is an air-to-air, air-to-water, or ground source heat pump… the investment can be significant. If you are planning to sell your current home within the next couple of years it may make more sense to simply replace whatever your home currently utilizes in terms of an HVAC system.

If you decide that a heat pump makes sense for you, then you’ll need to decide which type of heat pump best suits your needs. And… which system is the most affordable given your budget and the incentives that may be offered by various local, state/provincial, and federal governments.

For our situation a ducted air-to-air heat pump was the only approach that made sense since we were already using a ducted HVAC system.  We decided on an inverter heat pump rather than a single stage or 2-stage unit. A single stage unit operates in a simple on/off mode, while a 2 stage has one additional step in terms of the condenser operating capability.  An inverter condenser is able to ramp up and down incrementally so it can better adjust to changing heating/cooling requirements. As such it is more energy efficient than a single stage or 2-stage design.

We also decided that a high efficiency gas furnace that communicates with our heat pump was our best choice as a back-up heat source. Moving to an all electric system would have required us to update our electrical service from 100 amp to 200 amp. The air handler would also have been thousands of dollars more than a communicating gas furnace.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 44 mm, efov 88 mm, f/4, 1/60, ISO-6400

As a point of clarification, not all heat pumps and gas furnaces communicate with each other in terms of when each part of the HVAC system should handle the heating load during very cold periods. The system that we purchased is fully integrated in terms of the heat pump and gas furnace being in constant communication and analyzing heating needs. This is done through a system-specific, integrated Smart thermostat. (yes we have some drywall repair and painting to do).

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 14 mm, efov 28 mm, f/4, 1/1250, ISO-200

Choosing a contractor.

Like most things in life there will always be someone who is willing to sell products and services at a lower cost. It’s my view that installing a heat pump system is not a DIY proposition… or one that should be given to an underqualified technician.

You can invest a lot of money in a heat pump only to run into serious problems if it is not properly sized for your home’s needs, or is not installed properly. We decided on a local company that will be celebrating its 100th year in business in 2024. We had already been doing business with them for many years.

Some HVAC dealers do not have their own dedicated staff of technicians. Instead, they draw from a pool of freelance technicians, and often pay them a flat rate for each installation job. You can decide for yourself whether this approach will encourage a high quality installation or not.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 12 mm, efov 24 mm, f/4, +1 EV, 1/6, ISO-5000

Have a thorough inspection done before getting a quotation prepared, and making your purchase decision.

Installing a heat pump can be quite complicated, requiring specialized knowledge and experience. For example, where our HVAC system is located in our basement there is a lower than average height clearance. As you can see in the photograph above, there was only a couple of inches of clearance from the top of the heat pump ducting to the floor joists.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 12 mm, efov 24 mm, f/4, 1/250, ISO-6400

Transitioning from the ductwork and making turns into the ducting for the inverter heat pump/gas furnace also required some custom metal work.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 23 mm, efov 46 mm, f/4, 1/60, ISO-1600

As you can see in the photograph above, the gas furnace portion of our system is quite a bit smaller than our old gas furnace. Even though it has a 96% efficiency rating compared to our old furnace which had a 94% rating.

It is interesting to note that an inverter heat pump like the one we purchased can have an efficiency rating of 300% or more. That means that for every KWh of electricity that the inverter heat pump consumes, it can create 3 KWh or more of heat energy.

The size of the coil for our inverter heat pump is almost three times taller than the coil used for our old AC unit. There are many nuances like this that need to be considered.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 100 mm, efov 200 mm, f/4, 1/20 ISO-2500

Depending on the inverter heat pump system you select it may only be compatible with a dedicated Smart thermostat designed specifically for that brand or model of system.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 16 mm, efov 32 mm, f/4, -0.7 EV, 1/40, ISO-2500

If you replace your gas furnace with a new, system compatible gas furnace to act as a back-up heat source, you may discover that the venting for the gas furnace needs to be updated as it may not meet current building codes.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 12 mm, efov 24 mm, f/4, 1/60, ISO-5000

The wiring of the latest technology inverter heat pumps is quite complex. The system set-up can require a significant amount of fine tuning for it to run optimally. It requires someone with a good depth of experience and understanding.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 34 mm, efov 68 mm, f/4, 1/320, ISO-320

There is also a lot of testing that needs to be done during the unit commissioning process. The two technicians that did our installation, Nigel and Jamie, are consummate professionals.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 16 mm, efov 32 mm, f/4, 1/400, ISO-125

They spent the hours needed to thoroughly test our inverter heat pump and matching high efficiency gas furnace back-up. Then, we were walked through the operation of our One Touch Smart Thermostat.

OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 12 mm, efov 24 mm, f/4, 1/100, ISO-3200

Clearly identify your objectives to invest in an inverter heat pump.

There are many reasons why folks may consider updating their current HVAC system and moving to an inverter heat pump.

We had a number of objectives switching to an inverter heat pump system. These included:

  • Reducing our overall carbon footprint. We are located close to hydro electric power generation so using an inverter heat pump was a no brainer for us. For folks who live in areas where their electricity is generated by fossil fuels it may be counterproductive to switch to a heat pump from a carbon reduction standpoint.
  • Improving the comfort in our home by eliminating hot and cold spots. We’ve lived in our current home for almost 4 decades. We have never had even heating/cooling distribution in our home. For example, during hot months our master bedroom was always 5-6 degrees hotter than the first floor. Since installing our inverter heat pump the temperature in our master bedroom has improved and is now closer to the level on our main floor. We will need to monitor what happens with very hot and very cold days. The ‘low and slow’ heating and cooling of an inverter heat pump can make a difference in terms of comfort. The overall design of your house, the level of insulation, and the efficiency of your existing ductwork can all have an impact on heat distribution.
  • Reducing our overall energy costs. This remains to be determined as we have not had our inverter heat pump running long enough to calculate potential energy savings. I have created a couple of Excel spreadsheets to help me do those calculations in the future. One spreadsheet has recorded, and calculated, the daily minimum and maximum outside temperatures going back 13 months, as well as the average monthly minimum and maximum outside temperatures. My other spreadsheet has all of our utility costs for the past two years. This includes our monthly costs, as well as the number of energy units consumed by month. I’ve also done some calculations to convert cubic metres of natural gas consumption to KWh equivalents.
  • Reducing the noise generated by our HVAC system. This objective was easily met by simply listening to our inverter heat pump while it was going through its various tests at 100% load. I was standing about 10 feet away from our unit and it was barely audible. One of our neighbours across the street and three houses down was using an electric weed whacker at the time. The noise from his weed whacker from that distance was significantly louder than our inverter heat pump running at full throttle with me standing directly in front of it.
OM-D E-M1X + M.Zuiko PRO 12-100 mm f/4 IS @ 44 mm, efov 88 mm, f/4, 1/000, ISO-250

Learn to use your inverter heat pump to maximize its benefits.

Most of us have been taught to turn down our fossil fuel furnaces at night during cold months to save on fuel. Turning down an inverter heat pump at night is counterproductive and will end up consuming far more electricity as it will need to work hard to get back up to the higher temperature. The best approach is to find a comfortable temperature and leave it at that level. This approach allows your inverter heat pump to gently ramp up and down as needed… and thus consume less energy.

Of course your comfort levels may change depending on the season. Just remember that a fossil fuel furnace heats like a jack rabbit and drives heat up quickly. Then, it stops and waits for the temperature to drop down before it rushes to produce more heat again. This stop/start approach is very inefficient.

An inverter heat pump is the opposite as it takes a ‘low and slow’ approach. Once your desired comfort level is achieved the inverter compressor in the unit then slows down as needed to gently maintain the desired temperature. Turning your temperature down causes the inverter heat pump to work much harder to get back up to temperature… which then consumes more energy.

Technical Note

Photographs were captured handheld using camera gear as noted in the EXIF data.  Images were produced from RAW files using my standard process. This is the 1,287article published on this website since its original inception in 2015.

How you can help keep this site advertising free

My intent is to keep this photography blog advertising free. If you enjoyed this article and/or my website and would like to support my work, you can purchase an eBook, or make a donation through PayPal. Both are most appreciated.

Our eBooks…

The Finding Visual Expression eBook is designed to provide readers with some photographic inspiration and composition ideas. The Little Camera That Could details our extensive experience using the Nikon 1 system. Our eBooks also include a number of travel photography publications including Images of Ireland, New Zealand Tip-to-Tip, Desert & Mountain Memories, Images of Greece, and Nova Scotia Photography Tour. We also have a business leadership parable… Balancing Eggs.

Donations support this website…

If you click on the Donate button below you will find that there are three donation options: $7.50, $10.00 and $20.00. All are in Canadian funds. Plus, you can choose a different amount if you want. You can also increase your donation amount to help offset our costs associated with accepting your donation through PayPal. An ongoing, monthly contribution to support our work can also be done through the PayPal Donate button below.

You can make your donation through your PayPal account, or by using a number of credit card options.

Word of mouth is the best form of endorsement. If you like our website please let your friends and associates know about our work. Linking to this site or to specific articles is allowed with proper acknowledgement. Reproducing articles, or any of the images contained in them, on another website or in any social media posting is a Copyright infringement.

Article and images are Copyright 2023 Thomas Stirr. All rights reserved. No use, duplication or adaptation of any kind is allowed without written consent. If you see this article reproduced anywhere else it is an unauthorized and illegal use. Posting comments on offending websites and calling out individuals who steal intellectual property is always appreciated!

4 thoughts on “Inverter Heat Pump”

  1. Congratulations on this move, Tom, and your thorough research. I cannot understand the slow uptake of this technology, especially in this part of the world. My wife and I had a York heat pump in the late 70s-early 80s in Ottawa (yes, Ottawa!) and it was very satisfactory, extracting heat from outdoor air at -10C — way beyond its rating.

  2. Very interesting, Tom. Wish I’d had this information when we lived in Michigan; not too useful here in Arizona (;-).

Leave a Reply

Your email address will not be published. Required fields are marked *