Photo by U.S. Department of Energy
This two-part series documents homeowner Peter Callaway’s experience in a region that relies predominantly on fuel-oil for home heating to convert his household to a heat pump system. This heat pump system supplanted fossil fuels used for Peter’s heating, cooling and hot water heating needs with a more renewable alternative.
Part 1 describes how the author took advantage of a free home energy audit to make energy-efficiency changes and explains why the switch to heat-pump technology was made and what benefits were expected and achieved. Learn how to estimate running cost savings based on a Central Hudson online tool and how to calculate actual savings from actual use. In Part 2, find out how to work with a contractor and get the job done, with Peter’s thoughts on cost, technology, and service contracts. The author does not intend this article to be a recommendation or endorsement for a particular technology or contractor.
Installing a whole-house, heat pump-based heating and cooling system is a complex and expensive job. You need to be sure to choose an experienced, well established and dependable contractor who will work closely with you and supply you with any information you need to be comfortable with this long-term investment. With the requirement to eliminate the use of fossil fuels as soon as possible, there will be new arrivals on the scene and mistakes will be made, so you need someone who will be happy with you staying on top of the design and installation.
Where I live in New York State, the Energy Research and Development Agency (NYSERDA) maintains a list of contractors certified to perform home efficiency evaluations and upgrades but at this time, I don’t know if they do the same for heat pump HVAC contractors. You can search for qualified contractors in your area using the Internet.
I responded to glossy brochure marketing information and chose Go Green Express, a business in the nearby city of Newburgh, N.Y., and which is a certified Fujitsu dealers (meaning their technicians are trained by Fujitsu and they must achieve a minimum number of installs each year). And although the end result is what I want, mistakes were made and I paid more than I needed to because of those mistakes. I’ll help you avoid similar mistakes with recommendations in this text.
I’ll give you my thoughts on the four stages of the install process. Those stages are: sales and contract management; detailed load assessment and exact configuration specification; installation; and service. With a large contractor, different people may be involved in all four stages and you need to be assured that effective communication takes place between all involved. A small contractor may employ the same people for all stages. For a new contractor, there may be disorganization and confusion and unexpected schedule changes and learning-curve mistakes.
Photo by Revision Energy
Tips for Negotiating the Contracted Work for Home Heat Pumps
Because houses come in so many shapes and sizes, heat pump components come with many different capacities and temperature capabilities. Units come with heat-moving capacities in thousands of BTUs (British Thermal Units), such as 8,000, 12,000, 16,000, 24,000, 36,000, 48,000 BTUs. There are outside units (see top photo above), which contains the evaporator, condenser and maybe the geothermal hookup and where the heat exchange takes place. There also are indoor units, or heads, where the heated or cooled air is distributed and filtered and the remote-controlled mechanisms are housed. These indoor units may be ducted or direct.
With direct units (also called “mini splits”), there is one major air distributer that is mounted in a box high up on a wall in your main living areas (see photo below). For bedrooms and bathrooms, there is most likely one central air circulation, or distributor, ducted unit in the attic connected to the outside condenser/evaporator, with 4- to 6-inch insulated pipes (ducts) to carry the hot or cold air to ceiling vents in each room. Because each room has a ceiling vent, you can save energy by closing them off completely or partially for rooms not in use. You can also, in effect, set each room to a different temperature by adjusting the hand-screw vent opening.
The most critical parts of a new installation are: the careful measurement of the spaces to be heated and cooled, an estimate of how well your home is insulated, and consequently, a combination of units and their capacities in BTUs, and the placement of components that will achieve the desired result. This is the job of the contractor’s top HVAC technical expert and probably cannot be done by the salesperson who will make the pitch for his equipment and make a rough estimate of what you need and what it might cost.
This means that you should not sign a final contract until the detailed measurements have been made. (You could sign a letter of intent and make a down payment with the salesman.) The final contract should be clearly and accurately typed up so the installer knows exactly what he needs to install. Don’t accept hand-written scribble by an overeager salesman. You and the installer might not be able to read critical information.
If you don’t plan to keep your old heating system as backup, or don’t want the added expense of a geothermal heat source and sink, then make sure that the contract explicitly states that you require the extra-low temperature technology needed for air source heat pumps, especially in the Northeast’s colder climate. Do make the sale dependent upon the free removal of your old furnace or boiler and draining and sealing off the old baseboard or radiator hot-water system.
Ductless indoor mini split unit
Improvements in Air-Source Heat Pump Technology
Up until a few years ago, air-source heat pumps were inadequate for heating in the colder parts of the country and a geothermal component was required. Air-source heat pumps could only provide heat when the outside temperature was above 15 or 20 degrees. Now, most leading manufacturers have improved technology and can provide heat without geothermal when the outside temperature is as low as 0 degrees Fahrenheit. Below zero, efficiency tails off to zero at about -15 degrees.
If you install the old technology, you will have to keep your old fossil-fueled system as backup for the seriously cold months. If you install the new, extra-low temperature technology, you can get rid of your old fossil fuel system entirely, except for maybe a propane heater in case of extended electricity outage.
Finally, if you have an older house with an old power-distribution board, be prepared to upgrade to a modern 200-amp board with plenty of 220-volt slots (the same used by electrical clothes driers and stoves), because heat pumps use 220-volt, two-phase power, not 110-volt single-phase.
A note on noise: The compressor units are mounted outside the house and no noise is audible indoors. Some pump noise is audible outdoors near the units. The indoor air-distribution units require variable-speed fans that can be manually set to low, medium, high or auto — running the fan continuously on high might produce noticeable fan noise.
Costs and Home Heat Pump Service
I was shocked when I first saw my service plan costs. Charges are based on the number of heat pump systems installed and assume twice-yearly service: during spring before summer cooling and fall before winter heating. There will also be top-priority response 24/7 emergency calls during severe weather.
I have four heat pumps now. The 36,000-BTU unit costs $46 per month, the first 28,000-BTU unit costs $28 per month, the second 28,000-BUT unit costs $17 per month and the hot water heat pump $17.30 per month. The total is over $1,300 per year compared with about $300 per year for a comparable oil-burning baseboard-heating system.
My biggest source of confusion was in understanding what work needs to be done on a regular basis to maintain efficient operation of the system. There appears to be two levels of cleaning. First and easiest is simply taking the filters out, cleaning and drying them, and putting them back or replacing them with new ones. Almost any person with a bit of DIY ability can do this.
Second is the much more important job of keeping the heat exchanger components clean. That is, the coils and metal fins that transfer heat in or out of your home. In a mini split, there is one in both the outdoor and indoor units. Air is constantly circulated over these components either transferring heat into the system or transferring heat out of the system. Air is inevitably somewhat dirty these days and may contain dust, pollutants, hair, pet dander, cooking fumes, possibly smoking fumes, etc. These pollutants tend to stick to the coils and fins and then mold tends to grow in the muck, especially in humid climates or outside in dry dusty climates. This accumulation of muck gradually reduces the efficiency of the heat exchange and it takes more electricity to get the job done.
Clearly you need to ascertain the circumstances of your particular installation and figure a “deep cleaning” schedule. Deep cleaning involves removing the metal covers revealing the coils and fins, spraying them deeply with a special penetrating cleaning foam, leaving it for 15 to 20 minutes, then flushing it out with water. Easily done outside, but for those heads located up on your indoor walls, you’ll need a protective shroud and a funnel leading to a bucket. And you may have to be safely balanced on steps to reach the heads.
So the big questions are: How often should I schedule a deep clean? Are such cleans included in the service plan? If not, how much do they cost?
This is where the shock hit me. Deep cleaning was not included in the expensive service plan. I needed a head deep clean after two years of use, and it cost an extra $800 for ½ hour of work! I have three such heads in my house and one attic air-distribution head. How on earth do they clean that?
If you go online and do some research on deep cleaning, you can get detailed instruction on how to do it, but they still recommend that an expert do it for you. They do say that to keep you unit running efficiently and to ensure it lasts that you should do it once a year if you live in an area with lots of dirt in the air. These internet search results and the contractors recommend using air purifiers to keep accumulation of muck to a minimum, but Consumers Reports say that even the most expensive air purifiers only take out 30% at best and they can be noisy and use plenty of electricity (no heat pump advantage).
So it looks like frequency of deep cleaning will be a best guess based on likely pollutants present and degree of cleanliness of your home. The use of air purifiers may help a bit but will use more energy and require cleaning. Remember we got into this to reduce our HVAC costs and carbon footprint, but once you get into the details, it sure is a lot more complex and expensive an undertaking than servicing a simple and cheap oil or gas burner or hot water baseboard heat system.
Running heat pump-based HVAC systems may be more efficient and less expensive than using fossil fuels, but the servicing and maintenance of heat pump systems will negate savings. In my opinion, homeowners will have to want to use heat pumps to reduce fossil fuels and combat climate change rather than to save money or be more comfortable. Subsidies, tax credits and other incentives will be needed for mass adoption.
Peter Callaway is a Philipstown Climate Smart Community Task Force member and veteran environmentalist in the Hudson River Valley region of New York. He took on this extensive heat-pump conversion project to respond to recommendation 42 of the Project Drawdown framework.
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