How Hybrid Heat Can Increase Heat Pump Performance in Winter Help Your Customers Experience Comfortable, Consistent Heat All Season Long

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How Hybrid Heat Can Increase Heat Pump Performance In Winter Help your customers experience comfortable, consistent heat all season long

BY JESSE MARCUS

t’s a familiar routine for many HVACR profes- One way for HVACR professionals, especially in Isionals: The temperature drops during winter- colder climates, can limit the number of customers time and customers start calling about the per- calling about their underperforming heat pumps is to consider a hybrid heating solution. Hybrid heating sys- formance of their air source heat pump (ASHP). tems—sometimes called “dual fuel” systems—improve Because they can’t effectively extract enough ASHP performance by adding a high-eﬃ ciency natu- thermal energy from the colder outside air to ral gas or propane furnace that automatically cycles on produce a comfortable indoor temperature for during colder outdoor temperatures to supply much homeowners, heat pumps oftentimes don’t per- warmer, more comfortable heat to a home. form as well during colder periods. By capitalizing on the energy-saving strengths of both types of equipment hybrid heating systems can keep a homeowner’s house warm and more comfortable even in the coldest of winter. In a recent sur- vey asking consumers about the most important factors in select- ing an HVAC system, comfort was among the top four respons- es. Reliability, operating cost, and purchase price rounded out the top results. Th is growing body of consumer market research helps builders and contractors better understand the motivations behind homeowner decisions on HVAC purchases. Not only do hybrid heating systems meet consumers top four decision-making factors, but they also off er superior performance, increased energy eﬃ ciency, and reduced environmental impact.

14 RSES Journal FEBRUARY 2019 www.rsesjournal.com The basics of a hybrid heating system cools the air off too quickly, lowering its temperature Th e way in which a hybrid heating system combines an but not removing enough of the humidity. Because of ASHP with a high-effi ciency gas/propane furnace is this, indoor air is left cool but still humid, leading to relatively simple—it calls for heating from the piece of discomfort, moisture and potential mold problems. equipment which will be most eff ective and comfortable, taking into account the outdoor temperature. Hybrid heating systems still deliver Th e ASHP is called upon by the system’s controls to energy effi ciency provide heat when outdoor temperatures are 40°F or Hybrid heating systems can combine various effi ciency higher—a typical heat pump’s most effi ciency tempera- levels of both the heat pump and the furnace. High- ture range. When temperatures drop below 40°F and effi ciency propane furnaces are at least 90 AFUE and the heat pump becomes less effi cient and has less heat- can be up to 98 AFUE. To further improve effi ciency ing capacity, the high-effi ciency gas/propane furnace and assure a home’s indoor air quality, high-effi ciency automatically cycles on to provide heat. Th e propane furnaces take all air needed for combustion directly furnace typically delivers air at 115°F or higher, while the heat pump’s delivery air will be in from the outdoors. the 90s or low 100s as outdoor temperatures drop. Another key benefi t of the hybrid system is avoiding a heat pump’s use of electric resistance backup heat, PREMIUM which kicks on when a standalone heat pump can no longer keep up with the heating load on the home. Electric resistance backup heat is FLOAT VALVES very ineffi cient and also very expen- sive for the homeowner. FOR CHILLERS & COOLING TOWERS By combining the two heating systems, customers can experience year-round comfort and effi ciency, not to mention more control over their utility bills. Dual-fuel systems provide optimal performance In ASHP/propane furnace hybrids, when the propane furnace cycles on for heating—typically around 40°F— it greatly boosts the heating system’s output capacity and also assures that a warm air delivery temperature of 115°F or higher leaves the furnace. Hybrid heating systems also provide homeowners with fl exibility. As energy prices fl uctuate, or the home- Jobe Valves has the high quality owner prefers the warmer air delivery float valves for your HVAC needs, of the furnace, the transition point including feature packed valves can be adjusted upward or downward for chillers & cooling towers. by a contractor. Jobe Valves has the Additionally, hybrid heating valve for you! systems provide a redundant heating system. If the ASHP compressor Built-in anti-hammering feature experiences a problem, the home can ETL Certified to NSF372 Standards still be heated using the high-effi cien- UL94 Version Available cy gas/propane furnace. Surprisingly, Sizes from 3/4" – 2"! cooling performance also improves by Specializing in the manufacturing of premium float valves since 1967. combining a propane furnace with an See our full line of valves at jobevalves.com or call 800-680-3167. ASHP. An oversized cooling system Circle Reader Service No. 49 www.rsesjournal.com FEBRUARY 2019 RSES Journal 15 HVACR Professionals use cost savings and comfort as selling points While hybrid heating systems might cost a little more upfront, homeowners will see signifi cant annual energy savings. In fact, a hybrid system typically off ers a payback period of two years or less, based on its annual energy savings. And the system will off er

...hybrids comprising an ASHP and a high-eﬃ ciency propane furnace can save homeowners $400 or more a year...

improved comfort from day one. A recent study from PERC titled “A Comparative Analysis of Residential Heating Systems” found that hybrids comprising an ASHP and a high-effi ciency propane furnace can save homeowners $400 or more a year compared with a standard-effi ciency ASHP-only system. For instance, annual heating and cooling costs for a new home in a cold climate came out to $1,425 for a hybrid system and $1,840 for a standard efficiency ASHP system. ASHP-only and ASHP-propane furnace hybrid sys- A dual-fuel system benefi ts the environment tem is roughly equal to the greenhouse gas emissions of a passenger vehicle driven for six months. Over a Th is component is taking on more importance in system’s 15-year lifespan, the total diff erence in emis- many areas of the country as we grapple with reduc- sions would compare to the total emissions from a ing a home’s carbon footprint. Aside from renewable- passenger car over roughly seven years. based options, though, most heating systems will have carbon emissions linked to their operations. Reviewing your heat pump operation For ASHPs, the electricity that powers the system and maintenance checklist is often generated through fossil-fi red power genera- Like all heating and cooling systems, proper tion including coal and natural gas plants, leading maintenance is the key to effi cient operation. to upstream emissions. During periods when the According to the Department of Energy, the ASHP cannot meet the load due to colder outdoor temperatures, the ineffi cient electric resistance backup heat in ASHPs creates much higher carbon emissions. Hybrid ASHP-furnace systems avoid these The diff erence each year in emissions by relying on the furnace instead of electric carbon emissions...is roughly resistance back-up. As a result, hybrid systems in Midwestern locations can achieve a 38% reduction equal to the greenhouse gas in CO2 emissions compared with an ASHP-only emissions of a passenger system, based on a recent analysis. vehicle driven for six months. To put this value into more tangible terms, the diff erence each year in carbon emissions between an

16 RSES Journal FEBRUARY 2019 www.rsesjournal.com difference between energy consumption of a well-maintained heat pump and a severely neglected one ranges from 10%- 5%. Regardless of whether a customer has a better-performing hybrid system installed, professionals should refresh their maintenance checks as more customers place service calls during win- tertime. The DOE recommends homeowners ask their HVACR professional to check and maintain many items related to their heat pump, so professionals should be prepared when they arrive on site to handle the following:

• Inspect ducts, filters, blowers, and the indoor coil for dirt and other obstructions; • Diagnose and seal duct leakages; • Verify sufficient airflow by measurement; • Verify correct refrigerant charge by measurement; • Check for refrigerant leaks; • Inspect electric terminals and, if necessary, clean and tighten connections and apply nonconductive coating; • Lubricate motors and inspect belts for tightness and wear; • Verify correct electric control making sure that heating is locked out when the thermostat calls for cooling, and vice versa; and • Verify correct thermostat operation.

For technicians ready to take the next step and learn even more about how to install, service, and maintain propane heating systems, including hybrid heating systems, the Propane Education & Research Council may be an option.

Jesse Marcus is the director of residential and commercial business development at the Propane Educa- tion & Research Council. He can be reached at [email protected].

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