Heat Pump Outside Fan Work

Old 12-23-04, 04:45 AM
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Heat Pump Outside Fan Work

1. Temp Outside Last Night Was 15 And There Was Snow And Ice On The Ground. I Notcied That My Emergency Heat Kicked On, I Think It Went Into Defrost. My Question Is When The Unit Goes Into Defrost Does The Outside Fan Work. I Noticed A Humming Sound And Steam Comming From My Outside Unit, The Fan Was Not Moving. The Emergency Light Was On, And The Heat Strips Where Working. When The Emergency Heat Light Went Off The Outside Fan Started Working And The Humming Noise Went Away. Is This Normal Operation? The Noise Sounded Like The Fan Wanted To Run But It Couldnt.

2. I Noticed When The Outside Temp Gets Below 15 Degrees The Heat Pump Does Not Blow Very Warm Air. Is It Bad On The Unit To Switch It To Emergency Heat And Let It Run That Way Until The Outside Temp Warms Up Some To Help The Heat Pump Out? When It Gets That Cold Outside My Wife Get Uncomfrotable With The Heatpump. I Would Rather Run The Emergency Heat To Keep Her Happy And Pay The Higher Bills. I Just Want To Make Sure That Its Not Bad On The Unit.
Old 12-23-04, 06:19 AM
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Sometimes the strip heat will start and the fan will stop outside because: 1) it is defrosting 2) The unit cannot recover enough heat outdoors to avoid working against the strip heat. The outdoor fan is part of the heat recovery process and would stop when the heat pump is not pumping, that is, defrosting or operating solely from strip heat or off for some other reason.

You can run the strip heat with the added costs without damaging the unit. As I recall, there is a temperature below which heat pumps are not effective and require supplemental heat.

Hope this helps.
Old 12-23-04, 02:12 PM
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So When Its In Defrost The Fan Will Not Run. So The Buzzing Noise And The Burning Smell From The Outside Unit Is Normail During Defrost?
Old 12-24-04, 10:15 AM
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I'll try to explain this as it was explained to me. A heat pump is basically an air conditioner running backwards. To me, it seems that heat pumps are more efficient in the a/c mode. When you are in heat pump mode, your outside fan will run up until you go into defrost mode. When the heat pump goes into defrost mode, it reverses and now the hot air from the inside of your house goes outside to melt the ice on your condensor unit (outside unit). Normally when this happens, the auxilary heat kicks in to take over maintaining the temperature that your tstat is set for. When you are in the defrost mode, the fan will not run and at the end of the defrost cycle, you will hear a "WHOOSH" and probably will see a burst of steam shoot up from the outside unit. Then it reverses again and goes back in heat pump mode. If it's not too cold outside, your auxilary heat will then turn off. Hope this helped you. Happy Holidays. Jim
Old 12-24-04, 11:35 AM
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So When Its In Defrost The Fan Will Not Run. So The Buzzing Noise And The Burning Smell From The Outside Unit Is Normail During Defrost?
Yes its just like a AC unit only the fan dont run outside. The smoke is just the steam comeing off the hot coil out there. AS it is an AC then the strip heaters come on so you dont get the cold air form it.
The strip heats kick in if the tstat drops 2o and from set temp and the pump cant keep up. You can set the tstat to AUX or EME any time you want and not run the heat pump
You would have to look at the paper work for the unit but they all have a COP and that means like in most of them. At 30o outside you get 3 times more heat off of the heat pump for a dollar than you would off of strip heaters.
Keep the filter clean every 30 to 90 days and the big copper line should be warm to hot when it runs.

ED My .02 cent

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