s********r
发帖数: 2308 | 1 刚刚想起来给室外unit周围铲雪，发现居然其中的一台还在向上空使劲儿吹风。室内明
明在吹热风，怎么还需要室外的unit呢？ |
g*****9
发帖数: 4125 | 2 I think you have heat pump.
【在 s********r 的大作中提到】
: 刚刚想起来给室外unit周围铲雪，发现居然其中的一台还在向上空使劲儿吹风。室内明
: 明在吹热风，怎么还需要室外的unit呢？
|
s********r
发帖数: 2308 | 3 Still doesn't make sense ah... I think the outdoor unit serves as a radiator
... how come the radiator works when I am getting hot air?
【在 g*****9 的大作中提到】
: I think you have heat pump.
|
C*******d
发帖数: 15836 | 4 The fan is to get more air through your external unit so that it can grab
more heat from the air to be transported inside your house.
radiator
【在 s********r 的大作中提到】
: Still doesn't make sense ah... I think the outdoor unit serves as a radiator
: ... how come the radiator works when I am getting hot air?
|
i*******d
发帖数: 1430 | 5 就是把空调制冷倒过来用。仔细研究一下你家的空调，有可能是heat pump和gas
furnace双系统的，如果你的thermostat上除了heat还有aux heat之类的字样那八成就
是了。其中有一个使用气的，比用电便宜多了。
radiator
【在 s********r 的大作中提到】
: Still doesn't make sense ah... I think the outdoor unit serves as a radiator
: ... how come the radiator works when I am getting hot air?
|
z****n
发帖数: 1514 | 6 我听说的都是用电比用气便宜多了。
【在 i*******d 的大作中提到】
: 就是把空调制冷倒过来用。仔细研究一下你家的空调，有可能是heat pump和gas
: furnace双系统的，如果你的thermostat上除了heat还有aux heat之类的字样那八成就
: 是了。其中有一个使用气的，比用电便宜多了。
:
: radiator
|
v***s
发帖数: 1893 | 7 看室内外温差
【在 z****n 的大作中提到】
: 我听说的都是用电比用气便宜多了。
|
s**********d
发帖数: 36899 | 8
你只知其一，不知其二。
【在 z****n 的大作中提到】
: 我听说的都是用电比用气便宜多了。
|
s********r
发帖数: 2308 | 9 家里好像是两套系统，地下室一个烧gas的，管地下室和一层；阁楼上有一个应该是用
电的，管二楼。用电的就叫heat pump么？这玩意吹热风还要从室外走一圈？还是不解
，室内有两个进气口啊，要不然为什么还要定期换filter?
【在 i*******d 的大作中提到】
: 就是把空调制冷倒过来用。仔细研究一下你家的空调，有可能是heat pump和gas
: furnace双系统的，如果你的thermostat上除了heat还有aux heat之类的字样那八成就
: 是了。其中有一个使用气的，比用电便宜多了。
:
: radiator
|
g*****9
发帖数: 4125 | 10 You have 2 HVAC system in your house, FAG for downstairs, and air source
heat pump for upstairs.
Air source heat pump COP will drop when the outside is very cold. I usually
suggest a closed loop (vertical) ground source heat pump unless you are in
Miami.
Too much for me to explain here, so check this out.
http://home.howstuffworks.com/home-improvement/heating-and-cooling/heat-pump.htm
【在 s********r 的大作中提到】
: 家里好像是两套系统，地下室一个烧gas的，管地下室和一层；阁楼上有一个应该是用
: 电的，管二楼。用电的就叫heat pump么？这玩意吹热风还要从室外走一圈？还是不解
: ，室内有两个进气口啊，要不然为什么还要定期换filter?
|
|
|
s********r
发帖数: 2308 | 11 受教了。至少知道了我的HVAC system没出问题。
现在外面冰天雪地的，这个heat pump岂不是非常低效. 我是否应该干脆把楼下的gas
system温度调高来减少楼上的系统的工作？还有它有一个emergency heat，是不是用它
就变成电热丝发热从而停止那个Air-Source的compressor呢？
家里楼上恒温70度，楼下白天70晚上65度，上个月电费300气费200，该怎么设置比较有
效率呢？
usually
【在 g*****9 的大作中提到】
: You have 2 HVAC system in your house, FAG for downstairs, and air source
: heat pump for upstairs.
: Air source heat pump COP will drop when the outside is very cold. I usually
: suggest a closed loop (vertical) ground source heat pump unless you are in
: Miami.
: Too much for me to explain here, so check this out.
: http://home.howstuffworks.com/home-improvement/heating-and-cooling/heat-pump.htm
|
g*****9
发帖数: 4125 | 12 受教了。至少知道了我的HVAC system没出问题。
You are welcome
现在外面冰天雪地的，这个heat pump岂不是非常低效. 我是否应该干脆把楼下的gas
system温度调高来减少楼上的系统的工作？
Not sure what your gas price compare to electric price, different of the
country is different. But you could do that.
还有它有一个emergency heat，是不是用它
就变成电热丝发热从而停止那个Air-Source的compressor呢？
Yes, but COP of EM heat is always 1. With heat pump running, you might get
more than 1, even if is below freezing outside. But that depend on the
system you have.
家里楼上恒温70度，楼下白天70晚上65度，上个月电费300气费200，该怎么设置比 |
z****n
发帖数: 1514 | 13 Thank you for you infomation. Can you please teach me how to determine if
heat pump is cheaper or gas furnace is cheaper in my area where 1 thermal
gas is $1.10 and 1KWH electric is $0.09? Let's suppose the ourdoor temp is
35 F degree and indoor temp is 70 F degress.
【在 g*****9 的大作中提到】
: 受教了。至少知道了我的HVAC system没出问题。
: You are welcome
: 现在外面冰天雪地的，这个heat pump岂不是非常低效. 我是否应该干脆把楼下的gas
: system温度调高来减少楼上的系统的工作？
: Not sure what your gas price compare to electric price, different of the
: country is different. But you could do that.
: 还有它有一个emergency heat，是不是用它
: 就变成电热丝发热从而停止那个Air-Source的compressor呢？
: Yes, but COP of EM heat is always 1. With heat pump running, you might get
: more than 1, even if is below freezing outside. But that depend on the
|
g*****9
发帖数: 4125 | 14 1 BTU = 1055 J, and 1 watt-hour = 3600 J
I do not know the COP of your heat pump operating at 35 F degree and indoor
temp is 70 F degree. You can assume 1.5.
Gas furnace assume 0.9
Can you do it yourself now?
【在 z****n 的大作中提到】
: Thank you for you infomation. Can you please teach me how to determine if
: heat pump is cheaper or gas furnace is cheaper in my area where 1 thermal
: gas is $1.10 and 1KWH electric is $0.09? Let's suppose the ourdoor temp is
: 35 F degree and indoor temp is 70 F degress.
|
o****n
发帖数: 9475 | 15 你家的空调夏天管制冷，冬天管制热，想想国内用的挂壁机，你就明白了
【在 s********r 的大作中提到】
: 刚刚想起来给室外unit周围铲雪，发现居然其中的一台还在向上空使劲儿吹风。室内明
: 明在吹热风，怎么还需要室外的unit呢？
|
z****n
发帖数: 1514 | 16 Thanks a lot. What is COP? Can you please say something about the common
range of COP of heat pump?
This is what I googled: "In mild weather, COP may be around 4.0, while at temperatures below around −8 °C (17 °F) an air-source heat pump can achieve a COP of 2.5 or better, which is considerably more than the COP that may be achieved by conventional heating systems. The average COP over seasonal variation is typically 2.5-2.8"
indoor
【在 g*****9 的大作中提到】
: 1 BTU = 1055 J, and 1 watt-hour = 3600 J
: I do not know the COP of your heat pump operating at 35 F degree and indoor
: temp is 70 F degree. You can assume 1.5.
: Gas furnace assume 0.9
: Can you do it yourself now?
|
g*****9
发帖数: 4125 | 17 The term coefficient of performance (COP) is used to describe the ratio of
useful heat movement to work input. Most vapor-compression heat pumps
utilize electrically powered motors for their work input.
When used for heating a building on a mild day, a typical air-source heat
pump has a COP of 3 to 4, whereas a typical electric resistance heater has a
COP of 1.0. That is, one joule of electrical energy will cause a resistance
heater to produce one joule of useful heat, while under ideal conditio
【在 z****n 的大作中提到】
: Thanks a lot. What is COP? Can you please say something about the common
: range of COP of heat pump?
: This is what I googled: "In mild weather, COP may be around 4.0, while at temperatures below around −8 °C (17 °F) an air-source heat pump can achieve a COP of 2.5 or better, which is considerably more than the COP that may be achieved by conventional heating systems. The average COP over seasonal variation is typically 2.5-2.8"
:
: indoor
|
c****8
发帖数: 807 | |
O*******d
发帖数: 20343 | 19 29.3 KWH of electricity will generate same amount of heat by 1 therm of gas,
assuming you use resistant heating element for electricity.
【在 z****n 的大作中提到】
: Thank you for you infomation. Can you please teach me how to determine if
: heat pump is cheaper or gas furnace is cheaper in my area where 1 thermal
: gas is $1.10 and 1KWH electric is $0.09? Let's suppose the ourdoor temp is
: 35 F degree and indoor temp is 70 F degress.
|
