PDF Publication Title:
Text from PDF Page: 041
Bin range (oF) Hours in bin (hours) Average outdoor temp of bin (oF) % of design load Hours during which load ≥ this % of design load -10 ≤ -5 1 -7.5 127 1 -5 ≤ 0 9 -2.5 118.9 10 0≤5 4 2.5 110.7 14 5 ≤ 10 35 7.5 100 49 10 ≤ 15 74 12.5 94 123 15 ≤ 20 151 17.5 86 274 20 ≤ 25 256 22.5 78 530 25 ≤ 30 429 27.5 70 959 30 ≤ 35 674 32.5 62 1633 35 ≤ 40 848 37.5 53 2481 40 ≤ 45 828 42.5 45 3309 45 ≤ 50 757 47.5 37 4066 50 ≤ 55 766 52.5 29 4832 55 ≤ 60 781 57.5 20.5 5613 60 ≤ 65 804 62.5 12.3 6417 Figure 5-6 140 120 100 80 60 40 20 00 design load heating duration curve hours during which space heating load ≥ % of design load Figure 5-5 spreadsheet where this has been done, based on the Boston bin temperature data shown in Figure 5-4. The right side column in Figure 5-5 gives the hours during which the space heating load equals or exceeds each given percentage of design load. Plotting the last two columns of this spreadsheet up to outdoor temperatures of 65oF yields a “heating duration curve,” as shown in Figure 5-6. The yellow shaded area under the heating duration curve is approximately proportional to the total space heating energy needed over an average heating season. This is based on the assumption that internal heat gains alone supply the home’s heat loss at outdoor temperatures of 65oF or higher. The relationship between the area under the heating duration curve and the total seasonal space heating energy required can be very useful when combined with other building and heat pump performance data. Figure 5-7 shows one example. The graph of heat pump heating capacity and building supply water temperature (on right) is shown next to the heating duration curve for Boston. The graphs have been scaled so that the design heating load of 75,000 Btu/hr on the right graph aligns with the 100% of design load on the left graph. A line has been drawn horizontally from the balance point on the right graph to the vertical axis of the other graph. The green shaded area under this line represents about 94% of the total area under the heating duration curve. This implies that, on an average year, the selected heat pump alone supplies about 94% of the total space heating energy while operating at or above the outdoor balance point temperature. The remaining space heating energy is supplied through the combined operation of the heat pump and a supplemental heat source. The same horizontal line can be extended to the supply water temperature scale on the right graph. This shows that for 94% of the heating season, the required supply water temperature is at or below 103oF, a temperature that allows modern air-to-water heat pumps to run at relatively high COP. The low-ambient air-to-water heat pump assumed in this example could operate down to an outdoor temperature of -5oF. On an average year in Boston, there is only 1 hour of outdoor temperature lower than -5oF. Thus, the heat pump would remain in operation over essentially the full range of outdoor air temperature. The required supply water temperature corresponding to an 41 1000 2000 3000 4000 5000 6000 7000 % of design loadPDF Image | Heat Pump Systems 2020
PDF Search Title:
Heat Pump Systems 2020Original File Name Searched:
idronics_27_na.pdfDIY PDF Search: Google It | Yahoo | Bing
CO2 Organic Rankine Cycle Experimenter Platform The supercritical CO2 phase change system is both a heat pump and organic rankine cycle which can be used for those purposes and as a supercritical extractor for advanced subcritical and supercritical extraction technology. Uses include producing nanoparticles, precious metal CO2 extraction, lithium battery recycling, and other applications... More Info
Heat Pumps CO2 ORC Heat Pump System Platform More Info
CONTACT TEL: 608-238-6001 Email: greg@infinityturbine.com (Standard Web Page)