HIDDEN ISSUES WHEN INSTALLING HEAT PUMPS INTO BUILDINGS WITH EXISTING HEATING SYSTEMS
Multi-scale and/or multi-disciplinary approach to process-product innovation
Analysis of Energy-Environmental Issues (T3-3P)
Keywords: electric heating, hygroscopic, moist air, mass transfer, ventilation
Heating of buildings is big business and a vast field of individual solutions. For example may simple electric resistance heat be supplied by centralized forced-air electric furnaces or by heaters that are specific for each room. Room heaters can consist of electric baseboard heaters, electric wall heaters, electric radiant heat, or electric space heaters. It is also possible to use electric thermal storage systems to avoid heating during times of peak power demand but ventilation is needed all around the clock to have fresh air. Ventilation increases the complexity of the issue, whilst ventilation affects the heat balance as well as partial mass balances of for example oxygen, carbon dioxide or partial pressure of water vapor and even dust particles. Traditional board heaters are usually installed underneath windows. There, the heater's rising warm air counteracts with cool air falling from the cold window glass. Baseboard heaters are seldom located on interior walls because standard heating practice is to supply heat at the home's perimeter, where the greatest heat loss occurs. Board heaters should sit at least three-quarters of an inch (1.9 centimeters) above the floor or carpet. This is to allow the cooler air on the floor to flow under and through the radiator fins so that it can be heated. The heater should also fit tightly to the wall to prevent the warm air from convecting behind it and streaking the wall with dust particles (creating grey strikes). These detailed rules are the outcome of many decades of practical experience from heating of buildings.
Fluctuations in energy prices and new technology, raises new issues of how to renew heating systems in old buildings or how to build new ones. If electricity is the source of heat, novel heat pumps are easily motivated in most climates, as it is easy to convince consumers that total use of electricity may be cut by 50%. This has initiated market forces and heat pumps are today manufactured, sold and installed without any qualified supervision. Which in turn actualizes, once more, the question what is likely to happen when installing ad hoc heating or cooling (air conditioning) parallel to existing heating and ventilation systems? Should we as consumers just buy from sellers that forget to tell or not even know to tell about possible impact of ad hoc air conditioning! This seems to be once more an issue where we as consumers need to worry since no one else seems to care. Are we as consumers actually without our knowledge, in a desperate need of more in detail knowledge/legislation to rule out unsuccessful installations? Is it, for example, probable that unsuccessful heat pump installations might most likely cause new problems or even threat to our health! This is the issue that will be penetrated further in our extended abstract where surprising problems of an ad hoc heat pump installation (air conditioning unit) is exposed and exemplified. The example shows that even small heat pumps may have a surprising effect on local changes of temperature and relative humidity. The effect of the heat pump installation, which has been used for both heating as cooling, is illustrated by color pictures showing findings of mold stains. The article includes formulas and data on how to avoid mold stains, and factors that enforce conditions for local mold growth. The results of this work will increase knowledge of how heat pumps have to be used or installed in old or new buildings.
We believe increased knowledge and constructive criticism is needed to reduce the number of unsuccessful installations. Gained trust from successful installations is clearly needed to ensure that this mature, and environmentally friendly technology, after decades of development, gets consumers full approval!
See the full pdf manuscript of the abstract.
Presented Tuesday 18, 13:30 to 15:00, in session Analysis of Energy-Environmental Issues (T3-3P).
