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| Thread ID: 134467 | 2013-07-03 23:33:00 | Heat Pump | Driftwood (5551) | PC World Chat |
| Post ID | Timestamp | Content | User | ||
| 1347989 | 2013-07-03 23:33:00 | Regarding heat pump capacity & running costs. Situation. A 8kw heat pump has been supplying sufficiant heat for a home for 10 years. It is reaching the end of it's life & the owner has decided to replace it. Question. He has the choice of another 8kw or a 10kw for very little more. If he were to go for the 10kw unit, would it cost more to run as it wouldn't have to work as hard as the 8kw. |
Driftwood (5551) | ||
| 1347990 | 2013-07-04 00:17:00 | Regarding heat pump capacity & running costs. Situation. A 8kw heat pump has been supplying sufficiant heat for a home for 10 years. It is reaching the end of it's life & the owner has decided to replace it. Question. He has the choice of another 8kw or a 10kw for very little more. If he were to go for the 10kw unit, would it cost more to run as it wouldn't have to work as hard as the 8kw. 8Kw. Why pay more? |
pctek (84) | ||
| 1347991 | 2013-07-04 00:45:00 | But wouldnt it use less energy in the end if you got the bigger machine? as it would have to work less to get and keep the temp set? I dont have one myself but we have them at work....... i actually have no idea what size they are, but we have 2, side by side........and they get a lot of use. to keep and maintain temps. just my thoughts tho....could be wrong. |
beetle (243) | ||
| 1347992 | 2013-07-04 01:27:00 | It takes the same amount of energy to raise the same volume of air by the same temperature - more power just means it'll do it more quickly. The only way a 10KW should use more than an 8KW is if the 8KW wasn't up to the job and was running at max capacity all the time or you crank the new one all the way up to max and leave it there. By the same token it won't use less power either. For example if it takes 100KW/H to keep a house heated to 20 degrees for a week then that's what it takes. A 10KW heater will run at the equivalent of 10KW for 10 hours and an 8KW will run at the equivalent of 8KW for 12.5 hours. In practice though neither will do that, both will run at a reduced amount of power to maintain the temperature once they reach it, they 10KW will just get there faster. The power usage keeping it at a set temperature once reached should be the same. Also a 10 year old unit would be less efficient that a current one so they will probably both use less power. The best way to save money though is to not heat the house when you are not home, unless you have exceptional insulation don't leave A/C running 24/7 if someone isn't home for a good portion of that time. |
dugimodo (138) | ||
| 1347993 | 2013-07-04 01:49:00 | A bigger unit has bigger compressor which takes more power. It has bigger fans, with bigger thirst too. (A Kenworth with one occupant uses a shade more energy than a Corolla with one occupant too. ;) ) 25% bigger is quite a bit. | R2x1 (4628) | ||
| 1347994 | 2013-07-04 03:33:00 | It takes the same amount of energy to raise the same volume of air by the same temperature - more power just means it'll do it more quickly. The only way a 10KW should use more than an 8KW is if the 8KW wasn't up to the job and was running at max capacity all the time or you crank the new one all the way up to max and leave it there. By the same token it won't use less power either. For example if it takes 100KW/H to keep a house heated to 20 degrees for a week then that's what it takes. A 10KW heater will run at the equivalent of 10KW for 10 hours and an 8KW will run at the equivalent of 8KW for 12.5 hours. In practice though neither will do that, both will run at a reduced amount of power to maintain the temperature once they reach it, they 10KW will just get there faster. The power usage keeping it at a set temperature once reached should be the same. Also a 10 year old unit would be less efficient that a current one so they will probably both use less power. The best way to save money though is to not heat the house when you are not home, unless you have exceptional insulation don't leave A/C running 24/7 if someone isn't home for a good portion of that time. I like the logic in that. But you didn't say which one you would go for. |
Driftwood (5551) | ||
| 1347995 | 2013-07-04 03:50:00 | Because I don't have a strong preference, mine is only 6kw max output and it does the job for me. R2x1 makes a valid point regarding compressors and fans, I still don't think the running costs will be significantly different though unless the unit runs at full power for large amounts of time. |
dugimodo (138) | ||
| 1347996 | 2013-07-04 04:38:00 | We have two small ones and they work their little a r s e s off. Our friends have a very large one and it works very well on a temp. of 14deg, whereas ours is up at 23deg and slaving. We were told to leave it on Auto, rofl, might be alright in Auckland but no ChCh. Lurking. |
Lurking (218) | ||
| 1347997 | 2013-07-04 08:24:00 | We have two small ones and they work their little a r s e s off . Our friends have a very large one and it works very well on a temp . of 14deg, whereas ours is up at 23deg and slaving . We were told to leave it on Auto, rofl, might be alright in Auckland but no ChCh . Lurking . Yeah right, and certainly not in Taupo either . Mine is set on 20 at the moment but is struggling some days to keep us warm . End up turning it up to 22 some days! LL |
lakewoodlady (103) | ||
| 1347998 | 2013-07-04 08:28:00 | Rental we are in the crappy heat pump has to be on a min 24C to warm the house up and even then it struggles to keep us warm, glad we are moving at the end of the month into our own place again | gary67 (56) | ||
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