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Thread ID: 121726	2011-11-09 07:16:00	Are Heat pumps really economical?	mzee (3324)	PC World Chat

Post ID	Timestamp	Content	User
1242647	2011-11-09 07:16:00	Five and a half years ago I had a Heat pump installed. The pump has seized and the guarantee has run out. If the unit cost $2,400 it would pay for approx 6,000 units of electricity. Electric heaters are very cheap to buy, and the cost of the heat pump would pay for a lot of the power. Do I buy a new one or not? Don't have Gas.	mzee (3324)
1242648	2011-11-09 07:18:00	In our lounge with a highish ceiling and cos there is no attic above it ... no insulation, haven't done the insert from the outside method yet, rest of the house ceiling is insulated however. For us we save maybe $100 a month, plus compared to our single oil fin heater it is a lot warmer, no need jackets. If we did heat the room more and maybe employ 2 heaters, we may save $200 or 200+ a month in the winters.	Nomad (952)
1242649	2011-11-09 08:16:00	Have to agree with your original title "are they really worth it?". Last house i had it cost at least $100 month to run, but it was a big house so IMO no	Gobe1 (6290)
1242650	2011-11-09 09:08:00	Five and a half years ago I had a Heat pump installed. The pump has seized and the guarantee has run out. If the unit cost $2,400 it would pay for approx 6,000 units of electricity. Electric heaters are very cheap to buy, and the cost of the heat pump would pay for a lot of the power. Do I buy a new one or not? Don't have Gas. I think you should of gotten more than 5 years out of it. I have had one for 7 or 8 years. I think you should have a claim under the CGA under a reasonable life time. I think 5 years is not very long for a heat pump. Have a go at the people you bought it from. If they don't play ball threaten to take them to the disputes tribunal. I actually think a heat pump should last for at least 10 years. :)	Trev (427)
1242651	2011-11-09 14:09:00	We've had ours for about 5 years - still going strong... cool in summer, warm in winter. We have it running almost 24/7 and the cost is about $30 per month.	Greg (193)
1242652	2011-11-09 17:46:00	Five and a half years ago I had a Heat pump installed. The pump has seized . What brand. Everyone says it doesn't matter, I disagree with that. As for running costs, yes if you compare to normal electric heaters, no if you compare with wood burners.	pctek (84)
1242653	2011-11-09 21:18:00	Our Mitsubishi floor-mounted unit ran a bearing after 6 years. We bought an additional identical unit on the silent understanding that Mitsubishi would fix the other one first, for free. The new unit actually was cheaper in straight dollars - about $3800 installed (4kW) Heatpumps can save a lot of money on heating bills, but they're not designed to work in the way that NZers are accustomed to. NZers are accustomed to turning a heater on when it's cold and turning it off to save money. So a 1 kW heater running for 4 hours will cost a dollar. Heatpumps are not like that. They are based around temperature rather than energy usage. You can't set "1 kW" - you can only set "16deg" The trouble is, when a heatpump is installed we slavishly follow the instructions we're given instead of taking ownership. Those instructions basically say to set it at 20deg and leave it there, and that's what costs. (I've found that our new Mistubishi unit cannot do less that 18deg which it does at its minimum setting of 16deg ie, the control has a 2deg offset.) NZers are not accustomed to heating their house to 18deg while they're asleep. (Nor should they, IMHO.) The way to save money with a heatpump is to turn it off when you're not in the house, turn it back on when you return, and turn it off at night. If that means it's cold when you enter the room, turn on a couple of ordinary heaters for half an hour. That will cost 4kW x 25c x 0.5Hr = 50c	BBCmicro (15761)
1242654	2011-11-09 21:34:00	To expand on what BBC said a little. Yes Heat pumps are very economical, if you understand whats going on. They output about approx 3x the heat for the power they use compared to a conventional electric heater so a heatpump using 2KW will pump out around 6KW of heat, and to maintain a given temperature will use less power than an electric heater. What happens though as BBC said is people get them and leave them on, so of course the power bill goes up,sometimes considerably. I only use mine when I'm home, and awake, and feeling the need for heating or cooling. The rest of the time it's turned off. My power bill goes up a bit in winter and through the worst of summer, but really not too bad. If you think of them as a 2KW heater and use them as such they are very economical. The Heatpump warms my lounge quickly and easily, and heats the whole house reasonably well. In contrast my lounge, which is a large open area with no ceiling as such, is beyond the abilities of a fan or oil filled electric heater to heat. I used a portable gas heater for one season, the moisture buildup was insane. The best compromise I could come up with before the heatpump was to run both electric heaters for 30 mins then switch one off and just use the oil heater to maintain the warmth. The heatpump is definately cheaper than doing that.	dugimodo (138)
1242655	2011-11-09 22:05:00	I've always been curious about the marketing of heat pumps: you're never comparing apples with apples. Heat pumps are trying to heat a whole room to some set temperature as BBC says, whereas a bar heater is radiant heat and so mainly heats whatever is in front of it (including air which rises upwards towards the ceiling), and an oil fin heater is also a radiant heater but possibly less dangerous with small kids around as a bar heater. The fan heaters use convection and tries to heat the air and then move that bit out of the way to heat more air. There's a very large difference in the heating function itself between these different technologies. So if you're not around, a heat pump left "on" is doing what it was designed to do - heat a room to a certain temperature; and with good insulation and curtains closed, that warm air should stay in the room. If you get to keep the warm air, this is when they are the most "economical". Otherwise the warm air leaks out so you're better off turning it off when no-one is around or at night etc. And if your room is very very leaky, you are better off using a radiant heater of some sort, and sit in front of it (or use a hot water bottle). The single biggest reason why heat pumps are called energy efficient is because for every kWh you pay for to run the compressors and fans in a heat pump, the heat pump captures about 3 kWh (and up to 7kWh for some brands) of outside heat energy through its refrigeration cycle (using compressors, pumps and fans to move a refrigerant around between your room and the outside). All other heaters only give you 1kWh of heating for every 1kWh of power you pay for. So for some people the heat pump is extremely economical, but for many it is not. I work on the edge of this industry (not directly involved in the selling of air heat pumps), and people I talk to who find heat pumps economical tend to be people who use a reasonable amount heating (and were used to large power bills which came down after the heat pumps went in). For me, the cheapest form of heating is a wood burner (free fuel), and next up is a bar heater under my office desk which I switch off every time I leave the desk.	ellpow (16400)
1242656	2011-11-09 22:25:00	Another minor point i thought I'd mention. If you buy heat pump you WILL end up using it in summer to cool the house which is something a heater is never used for. That power is something to factor in to the overall costs. I got mine and resolved to only use it for heating, but you quickly change your mind when it gets hot. I would never go back myself though, heatpumps are great.	dugimodo (138)
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