https://www.sohu.com/a/329249996_120207616
前提:热泵的最佳工作气温,北美都设在47℉,所以基本热泵在这个温度,都可以达到标称的heating BTU,气温降低,输出BTU会降低,但house需要的BTU却是升高的,就算HSPF高,可以在很低温度维持BTU不变,也无法满足house heating的需求。比如house安装80000BTU furnace,一般会配3吨空调(热泵),那3吨热泵最高才36000BTU。所以热泵制热是有温度要求的,在这里一般在shoulder season启用,象现在这个时节的多伦多。by havctech
one cubic foot of natural gas = 1,030 BTUs.
我们以80000BTUS 炉子来比较:
80000/1030=77.67cf, 炉子效率90%, 耗气:86.3 cf.
cost: 86.3x0.0176=1.52$ (0.0176 来自我家,用气236立米,交费$146.21)
HSPF is defined as the ratio of heat output (measured in BTUs) over the heating season to electricity used (measured in watt-hours).[1][2] It therefore has units of BTU/watt-hr.
假如热泵效率9HSPF, 那么80000BTUS
80000/9=8888.89watt.h=8.89kwh
cost: 8.89x0.16=$1.42 (0.16 同样来自我家实际数据,调整后用电 769.355,缴费: 125.62)
结论:在理想情况下,环境温度47℉(8.3℃)用效率9HSPF的热泵产生80000BTU的热量,比用气省 0.1加元。