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Thread ID: 109075	2010-04-23 06:32:00	How much really cheaper is a heat pump?	Nomad (952)	PC World Chat

Post ID	Timestamp	Content	User
879415	2010-04-23 08:33:00	I guess what I like to read up on is on a typical NZ winter how the 2 would compare. 2.4kW HP set at 20 degrees. 2.4kW electric heater with thermostat set at 20 degrees. Or maybe even 2.4kW electric heater set at 20 degrees and when it has reached this you can reduce the power to 1/3 or 2/3 instead. Oil column heaters tend to have either of the 2 buttons or both on. I'm starting to question the 3x bang for your buck theory ... For the main room the conveience may be worth it, sure and we are getting one. But questioning it for the bedroom. I had one installed in my mothers old house. She used to have an oil column heater bubbling away at medium in the hallway and it barely made any difference. She noticed no change in the power bill but the whole house was warm.	mikebartnz (21)
879416	2010-04-23 08:34:00	I certainly would not consider a heatpump just for a bedroom.You can buy overcoats and woolly dressing gowns one hell of a lot cheaper.	Sweep (90)
879417	2010-04-23 08:37:00	This (http://www.energywise.govt.nz/) site may answer your questions. :)	Trev (427)
879418	2010-04-23 08:41:00	A 2.4kW oil column certainly heats up my room, without a thermostat it overheats. 2.5 x 3.5m. Just thought about the HP because it might be more economical, save a power socket and off the floor. Now I am starting to question it. Mike, were the doors shut and how did the kW compared between the HP and the electric oil heater?	Nomad (952)
879419	2010-04-23 09:00:00	Thanks Trev, I had a revisit of that website, I have also seen Consumer NZ and Energy Spot . I also ended up downloading a HP guide . It talks about COP that each dollar buys three dollars of heat . But that might not be correct all the time . At start up the HP probably would use a higher kW setting and to maintain the room it may work at 1/3 . A oil column heater may work at 1/1, it is using more power than a HP but from a practical perspective not all the time when it has reached that temperature, the power would cut off by the thermostat . I wished someone compared a 4hr session of a HP set at 20 degrees and then to the oil column heater set at 20 degrees as well and measure how many kW did each use . The document did say if you turn it on a few hrs at night and 1hr in the morning, you may save under $200 a year . :rolleyes:	Nomad (952)
879420	2010-04-23 09:29:00	Thanks Trev, I had a revisit of that website, I have also seen Consumer NZ and Energy Spot . I also ended up downloading a HP guide . It talks about COP that each dollar buys three dollars of heat . But that might not be correct all the time . At start up the HP probably would use a higher kW setting and to maintain the room it may work at 1/3 . A oil column heater may work at 1/1, it is using more power than a HP but from a practical perspective not all the time when it has reached that temperature, the power would cut off by the thermostat . I wished someone compared a 4hr session of a HP set at 20 degrees and then to the oil column heater set at 20 degrees as well and measure how many kW did each use . The document did say if you turn it on a few hrs at night and 1hr in the morning, you may save under $200 a year . :rolleyes: The bottom line is this: - An oil column or other electric heater will always give you a maximum of $1 of heat for every $1 of electricity - A heatpump will deliver between $1 to $5 of heat for every $1 of electricity Your thermostat question is irrelevant, if you are comparing apples with apples - i . e . both heatpump and oil column heater have an _accurate_ thermostat, etc . Of course, spending a couple of thousand dollars on a heatpump, compared to $100 for an electric heater may outweigh any cost savings you get in the short term .	somebody (208)
879421	2010-04-23 09:52:00	Some of the std electric heaters have a thermostat. None of our 6 heaters have them. Hence I was referring to a optional thermostat for our current heaters. I guess the most ideal way is to set the std heater at 20 degrees for 4hrs and check the power meter before and after and do the same to the inverter HP the next day. I won't be surprised if I only save $100 a year. I don't use it in the mornings, hit the shower, 5min Weetbix - dunk it in, brush teeth, get changed and out to the bus stop. 45min from the time I get up :D Not sure if we get one for the bedroom and due to the high ceiling doing a power meter comparison with the lounge is not a good base line. If this was SE Asia people may get them regardless given the climate ... but I know a few people who live in non air conditioned housing :p	Nomad (952)
879422	2010-04-23 10:38:00	Mike, were the doors shut and how did the kW compared between the HP and the electric oil heater? The internal doors were open. The oil heater running on medium would have been about 1100 to 1400w and the HP was about 5kw but should have been larger.	mikebartnz (21)
879423	2010-04-23 10:43:00	The internal doors were open. The oil heater running on medium would have been about 1400w and the HP was about 5kw but should have been larger. We don't heat corridors as such. Folks like to leave the kitchen, bathroom, and laundry windows permanently opened. It's their thing. Dad has his bedroom window open throughout the year. He says if you turn on the heater you need to leave a small gap for the window - for your health :D In fact you cannot even close many of the windows now cos they are so tight. Our lounge we are getting a 6kW HP, for many years we have always cuddled up to the 2.4kW oil column heater while watching TV, only 1 or 2 winters ago we chose to have 2x 2.4kW heaters but it still took a few hours to heat up with a 4 or 5m ceiling :p Seriously you have 2 adults sitting close to the heater like 15cm away, one might be on a single seater sofa and the other sitting on the carpet cross legged :D We have a traditional NZ house, one heater in the lounge, one in the bedroom and a small fan heater in the bathroom :thumbs:	Nomad (952)
879424	2010-04-23 10:44:00	There's a few more considerations... Despite the marketing spin, the refrigerants used in heat pumps are still enviromentally damaging. There are a variety of refriogerant options, but the hardware must be designed for only one specific refrigerant, as they work at different pressures, and have differing corrosive profiles, which means that the wrong refrigerant will rot out the pipes / compressors in a heat pump. My concern is that at the eventual time when a heat pump needs servicing, we will probably find that the refrigerant is banned at that point in time... rendering the entire system an expensive pile of excrement, which no longer has a compatible refrigerant available for continued use. The other factor which you've not reported, is that some systems can have multiple internal units (ie heating a number of rooms independantly) for one single outdoor unit. This adds an extra degree of value to a unit, particularly if only one room is in use at a time (eg, living room heating, then bedroom heating, but never both at once). However, it also means that a breakdown and servicing (and refrigerant issues) may arise even sooner with the extra hardware installed, and even more investment that has to be trashed if the refrigerant is unavailable. Last option - if you own the home - install a false ceiling (eg suspended), and add insulation over the lower false ceiling, and battle on in the traditional way with your heating needs. Final consideration, if and when we find these refrigerants are banned, are you prepared to pay an additional fee for collection and destruction of the refrigerant? There might be such laws in place in the future, particularly if this global warming thing turns out to be running amok, as many of the models are predicting. Yeah, extra clothes still have some appeal.	Paul.Cov (425)
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