Help me choose a heat pump

[vifferman]

Mitsibishi.

Skyryder

Didja mean "Mitsubishi"?
If so, which - Mitsubishu Electric, or Mitsubishi Heavy Industries?
According to our installer, the latter has more experience and is a bigger player in the market (especially commercial), and most of it's R&D is passed on to its sibling, Mitsubishi Electric, who deal more with home appliances.
At his recommendation, we opted for the Mitsubishi Heavy Industries models (we have two), as they rated marginally better on the specs for energy consumption and noise output.

My in-laws bought two Panasonic units - they're smaller and less obtrusive than ours, but noticeably less effective (despite their house being newer and better insulated than ours). They bought Panasonic mainly because they were the only company to offer a unit with a self-cleaning filter. Unfortunately, because NZ gets whatever models Australia decides are best, and Aussies go for performance and value-for-money over features, by the time my father-in-law got around to ordering his, they weren't available any more.

[Max Preload]

Actually my point around the heat pump and HRVs still stands

An HRV is cheaper to install - but it doesn't (really) heat your home - it dries it - hence my saying they are not in the same league

You get a degree or two more warmth - not the change we got from 4 degrees inside one morning to 16 an hour and a half later (yes, I'm so anal I watched the thermometer)

I agree with you totally - traditional resistance heaters are SHOCKINGLY expensive for no real gain and gas heaters just pump more moisture in

As I said before - ours costs us around $65 per month in winter and I have no regrets - the whole house is warm and dry - and it's a crappy 1979 New Zealand masterpiece of thin fibrelite, corrugated iron and MDF floors...

I was commenting on them being in the same league price wise - last time I checked the HRV wasn't far off the price to a heat pump and they're certainly not in the same league performance wise.

As a side note, people often make claims about excessive power consumption from oil column heaters and they won't listen to the fact that they use no more power for the same heating effect as a fan, panel or bar heater i.e. their efficiency is the same. But oil column heaters have to be used differently to get the same result. The heat that remains in a oil column heater is not utilised if you switch it off just as you go to bed - they should be turned on about an hour before they're actually needed and turned off about an hour before the time they're no longer needed as their effect is not immediate - it lags due to the need to heat the oil before the heat is felt in the room.

[vifferman]

As a side note, people often make claims about excessive power consumption from oil column heaters and they won't listen to the fact that they use no more power for the same heating effect as a fan, panel or bar heater i.e. their efficiency is the same. But oil column heaters have to be used differently to get the same result.

I think part of it is that oil column heaters have been hyped up to be more economical and safer than other heaters. The problem is they take longer to give out heat, and they don't circulate the heat at all.

HRV is similar in that sales seem to have been driven by some hype and exaggeration of the effectiveness of the units. My beef is that for what they are, they should be cheaper, and for what they cost, you're far better off spending a bit extra and getting a heat pump.

Before we had aircon installed, we had a large firebox in our lounge. We ripped it out because of the mess from ash and smoke (if it was a gusty night, smoke would puff out of the firebox or flue into the lounge). Also, I was the only one who took care of lighting it, cleaning out the ash, cutting up wood, etc etc.
We ripped it out, and were going to install a gas heater (had them in three other homes) when we realised if we got a heat pump instead we could use it in the summer as well. One of the better decisions we've made.

[Fatjim]

Actually oil coolumn heaters make you feel warmer than a fan heater for the same heat output. They also maintain a steady heat in the room.

But 1kw of heat is still 1kw of heat.

[Max Preload]

I think part of it is that oil column heaters have been hyped up to be more economical and safer than other heaters. The problem is they take longer to give out heat, and they don't circulate the heat at all.

I've never seen any such claims of better economy. They're certainly safer around children and pets as the surface temperatures are considerably lower than that of a bar heater. They circulate heat but most by convection so you do get uneven temperature across the room.

HRV is similar in that sales seem to have been driven by some hype and exaggeration of the effectiveness of the units. My beef is that for what they are, they should be cheaper, and for what they cost, you're far better off spending a bit extra and getting a heat pump.

Absolutely. HRV & DVS systems should be much cheaper. Heat pumps are priced about right for the return in savings.

Actually oil column heaters make you feel warmer than a fan heater for the same heat output.

Only because of the fan - if you're not sitting directly in front of a fan heater it'll feel similar and heat the room more evenly.

[Lias]

It should also be worth noting that if you have asthmatics or allergy sufferers in the house, the best brand is a Fujitsu for their plasma filters.

[Fatjim]

Absolutely. HRV & DVS systems should be much cheaper. Heat pumps are priced about right for the return in savings.

This pisses me off in two ways. Firstly the people that get ripped off for a DVS system thats a $50 fan and a bit of tubing. The most expensive bit is th controller, but you pay extra for that!

Secondly, why should stuff be solely priced on what it saves you, why bother buying something for $5000 to line the pockets of someone when it only saves you $500 over 10 years. This is the case in heat pump hot water systems. I think they are a great idea, but why spend an extra $3000 getting one? This is one area where I think the gummint needs to step in. Although I'm not sure what they could do.

[Kiwi Graham:Me]

I've got three....Fujitsu's. There quiet and do exactly what there supposed to. You get a six year warrenty with them as well.
Careful siting is important but the consultant will help you with that, their multi directional anyway.
In this current climate you should be able to do a deal on price!

[vifferman]

Actually oil coolumn heaters make you feel warmer than a fan heater for the same heat output.

You're not supposed to sit on them, y'know...

[BMWST?]

despite the hype,and misleading names,HRV is only a ventilation system,that takes advatage of warmer air in the roof space.They are not a heating system.
A heat pump is very efficient in that it is not "making" heat,it transfres heat from outside to inside(or visa versa) in exactly the same way a fridge transfers heat from inside to outside
If you are considering heating in Dunedin,have you considered a pellet burner.?

[Max Preload]

...why should stuff be solely priced on what it saves you, why bother buying something for $5000 to line the pockets of someone when it only saves you $500 over 10 years. This is the case in heat pump hot water systems. I think they are a great idea, but why spend an extra $3000 getting one? This is one area where I think the gummint needs to step in. Although I'm not sure what they could do.

You lost me here. As far as I'm concerned that is the primary criteria - no point in it costing more than it's going to save you in its useful life. That's not to say I would object to it costing less and the payback time being less.

[vifferman]

You lost me here. As far as I'm concerned that is the primary criteria - no point in it costing more than it's going to save you in its useful life. That's not to say I would object to it costing less and the payback time being less.

?
Now you've lost me.
My primary criteria was to get some heating for the lounge. When I realised I could cool the lounge in winter as well, I changed from a gas heater to aircon, and got it for the basement as well. Being more cost-effective than any other form of heating was just an added benefit/incentive, not the primary one. It's not making money - it's a straight cost, albeit less than any other form of heating. However (but!) that's kinda negated by using it to cool the house in summer, as if I'd got some other form of heating there'd by no costs in the summertime.

Frankly, I don't really care. I just have to accept I have three parasites that cost me lots of money: each month I fork out $300 for power, $200+ for teh Interdweeb, and about $1500 for food and drink. I've given up trying to actually save any money.

[0lddog]

HRV is similar in that sales seem to have been driven by some hype and exaggeration of the effectiveness of the units. My beef is that for what they are, they should be cheaper, and for what they cost, you're far better off spending a bit extra and getting a heat pump..

Top of the morning from the Emerald Isle,

Its not really a case of HRV replacing a heat pump

HRV requires an air tight building that is very insulated. Otherwise its a waste of time ( er, thats money that I mean )

Most of the heat pump makers also offer HRV units that integrate into the their heat pump duct indoor units.

Mitsi have the losnay ( loosnay ? ) Daiken have one too

In the case of mitsi they have a 7 day controller that you can set up to control both the heat pump and HRV.

Does Dunedin really go down to -15C in winter ?

[davereid]

Do they save much money ?

Say 5 kw conventional heater, using 5 kw power for 5 hours a day @$0.20 kw/hr. $5 day running cost or $450 per year if you heat every day of winter.

Heat pump will cost possibly as little as 1/4 of that amount, but likely closer to 1/3, say $150 per year.

This saves $300 per year.

If your heat pump cost $4000 installed, you will break even after 13.3 years.

If you still own the house, and the heat pump is still going well, and hasn't required any repairs that is.

Of course, if you use the heat pump more, or for longer you will have a shorter rate of return, and if you use it less, a much longer period will be required before it can be considered a good investment.

On the other hand, if you chucked the $4000 in bonus bonds, and managed a real 4% return you would earn $160 a year in payouts. Which if they went on your power bill, would give the heat pump a 27 year break even point.

[Winston001]

Does Dunedin really go down to -15C in winter ?

Sure and its fine to be hearing from the land of the Little People. As for Dunedin.....15 degrees of frost? No.

It certainly gets cold and damp in the bottom of the valleys but not -15.

Do they save much money ?

Say 5 kw conventional heater, using 5 kw power for 5 hours a day @$0.20 kw/hr. $5 day running cost or $450 per year if you heat every day of winter.

Heat pump will cost possibly as little as 1/4 of that amount, but likely closer to 1/3, say $150 per year.

This saves $300 per year.

If your heat pump cost $4000 installed, you will break even after 13.3 years.

If you still own the house, and the heat pump is still going well, and hasn't required any repairs that is.

Of course, if you use the heat pump more, or for longer you will have a shorter rate of return, and if you use it less, a much longer period will be required before it can be considered a good investment.

On the other hand, if you chucked the $4000 in bonus bonds, and managed a real 4% return you would earn $160 a year in payouts. Which if they went on your power bill, would give the heat pump a 27 year break even point.

Good calculations which seem pretty accurate, although I understood that maximum efficiency was 1:3 ie. 1kw electricity produces 3kw of heat. When the ambient temperature is close to or below zero, the efficiency is less - just when you use it most.

Never mind. People who install heatpumps say their power bills don't change, in fact may rise a little, but the vast improvement in warmth and dryness of the house is worth every cent. Marvellous.