The balance point (temp at which HP must run continuously to maintain setpoint) can be calculated by plotting heat loss and heatpump output.

If you go for the trane unit, check the heating capacity ratings; if I recall correctly (from reading spec sheets), some trane HPs are weak.

A Dual fuel system must be a nice however the energy savings in mild weather may not offset the price premium over a reasonable amount of time.

We installed the Zuba in October last year. We love it. So far, temperatures have gone down to minus 14c and the system just kept chugging along. I cannot even imagine what magic makes this thing work but, I'm nice and warm and toasty as we speak.

magic makes this thing work but,

Variable capacity compressor which can ramp up in cold weather and produce high compression ratio = good cold climate performance. As long as the refrigerant's boiling point (proportional to pressure) is below the outdoor temp, there's plenty of heat in the air to harness - -14 is far above absolute zero. :)

We installed the Zuba in October last year. We love it. So far, temperatures have gone down to minus 14c and the system just kept chugging along. I cannot even imagine what magic makes this thing work but, I'm nice and warm and toasty as we speak.Wow! Mine still does not produce any heat below freezing.

Biggar,

Can you give us an idea of your previous installation and also a ball park figure of your cost for equipment + installation of your Zuba system please.

It seems promising . . . .

Wow! Mine still does not produce any heat below freezing.

That's a shame.

It should give some heat (coolish-lukewarm air), but not enough to maintain the setpoint without a little help from the heat strips as required.

That's a shame.

It should give some heat (coolish-lukewarm air), but not enough to maintain the setpoint without a little help from the heat strips as required.

It does provide some (coolish-lukewarm air) but it stops being able to reach/maintain the setpoint when the outside temperature gets to be around freezing. That's why I turn off the breaker for the heatpump when the temperature drops in the fall and turn it back on in the spring. I'm no expert but I can't see why I would let a 3KW heatpump run and add to my electric bill if it's not producing useful heat.

As I may have said earlier, I am still disappointed though because I had been told that one could use only a heatpump down to minus 12 or so.

That sounds normal.

3kw running a compressor and fan motor goes a much longer way than powering a set of elements.

All of the energy consumed by the compressor actually gets absorbed by the refrigerant and released into the house (it doesn't get wasted) - whatever heat the outdoor coil picks up (another 3-6kw depending on weather) beyond that is free. When the t-stat is set up correctly, the heat strips are supposed to cycle in and out as required to maintain the setpoint without shutting down the heatpump.

If I was in that position, I would experiment to see if the heatpump is actually saving any money (alternating between HP and 100% electric and reading the electric meter daily, taking weather into account), but most people don't have the time/patience to do that.

Slyvain said;
"[QUOTE]it does provide some (coolish-lukewarm air) but it stops being able to reach/maintain the setpoint when the outside temperature gets to be around freezing. That's why I turn off the breaker for the heatpump when the temperature drops in the fall and turn it back on in the spring. I'm no expert but I can't see why I would let a 3KW heatpump run and add to my electric bill if it's not producing useful heat.
As I may have said earlier, I am still disappointed though because I had been told that one could use only a heatpump down to minus 12 or so."

i'm on my 2nd winter with a fuji heat pump it works great even at -15c temps. i think the specs show a limit of -15c. however i can vouch it works fine and i know 2 others in my neigbourhood with the same unit. Note- i dont bother with my furnace at all.

i'm on my 2nd winter with a fuji heat pump it works great even at -15c temps. i think the specs show a limit of -15c. however i can vouch it works fine and i know 2 others in my neigbourhood with the same unit. Note- i dont bother with my furnace at all.
Wow! I wish that's the heatpump I had.

Many mini-splits are designed to actually work well in cold climates.

The central units on the other hand are not and require supplemental heat - they can still put a dent in electric heating costs when set up correctly. (...and the user is educated how they're designed to operate)

We live on the North Coast of BC, average temp year round is 7C.
We have gone from approx. $2000 to $2400 year in NG heating costs to about $800 year. Electrical has gone up only a bit. That has been hard to figure out given recent rate increases and we run our furnace fan on a recirc. mode.
With a new HE NG furnace and heat pump (both Payne) sized for a 2000 sg ft home our cost was $11,500 and with grants worked out to $3100.
Expected pay back is in 5-7 years at our old utility pricing. With hydro (especially) and gas rising pay back might even be sooner.
We keep our home warmer and with the recirculation setting on the furnace fan our home has less condensation on our windows.
This area is one of the few where heat pumps are recommended. Mainly because the temperature swings are so minimal.
The only drawback so far has been the noise of the heat pump on our quiet street.

It was around minus 20 c last night here and my Mits was still making heat!:D

Unbelievable! I actuality turn off my heatpump in the winter as it has been useless below freezing...
I saw in another Digital Home thread that a study says the problem is often due to installation.

Why resurrect an old thread?

Those variable capacity mini-splits can actually ramp up to maintain capacity as it gets colder, unlike conventional single speed models which fall behind below freezing when sizing for cooling.

Asian mini-splits are far more advanced than north american central air models - almost like comparing a computer to a type-writer. :D

Almost everybody I know purchased a heat pump and all tell me they are great,and the house is warm and that's all they use. Then I drive by their houses and they have smoke or steam coming out of the chimney. Uh huh, oh well my power bill is high enough and I'm putting anything on my house to put it any higher. By the way I burn wood for approx. 800$ a winter. But they sure are nice for ac in the summer:)