Why dig??

Xringer · 01-19-11, 08:44 AM

Mitsubishi Electric Sales Canada Inc. - Air Conditioning & Heating

"Zuba-Central is capable of heating efficiently down to -30°C and beyond."

If you live in Canada that is..

davranyou · 01-19-11, 10:21 AM

Can this thing extract heat from the surrounding area when buried in 4 and half feet of snow? Snowfall has been crazy this year!

Xringer · 01-19-11, 11:58 AM

I've heard there might be a few decades of cooling before the global warming really kicks in.

I've been cleaning up the wall of snow around my Sanyo.
Luckily, we had a January Thaw and some rain to clean off the areas where we've
been cleaning off the walks, driveway & parts of the roofs we can reach.

I've got an old snow-rake, leftover from the days when we have solar hotwater panels.
It's coming in real handy for keeping the gutters from being ripped off by the ice ridge.

40F today and back to the 20s F tonight, more snow Friday and below zero F this weekend.

I think the Zuba system will work like most mini-splits, when the coil sucks in too much snow.
It will preform a defrost cycle (while your house cools a little) and then kick back into heating mode.

I find we can avoid some defrost cycles by shutting down the heat when the
wind is blowing the snow and it's is really coming down.
Once the worse is over, it can be turned back on. You just need some good backup heat in the meantime.

strider3700 · 01-19-11, 12:11 PM

Interesting my heat pump just gives up and kicks on the back up at -4C it would be nice to go a little colder without needing that. Right now I just use the woodstove on real cold days though.

For global warming insulation and lots of it is your best friend. We can probably expect brutal hot summers and brutal cold winters with some wicked storms thrown in for the mix. Last year our town has set a new record high and a new record low...

Xringer · 01-19-11, 01:04 PM

The Sanyo is okay down to about -12C. It still puts out heat, but I'm not sure
how many BTUs I'm getting per watt. I don't think it's all that much.

When I see less than -10C in the forecast, I turn on the flow-through valve,
to allow oil+PV heated water to circulate in the baseboards.
If it's going to stay cold for a long time, I'll set the oil burner timer to kick
in an re-heat the water. 30 minutes on for each 90 to 120 minutes off.

If it going to be colder, (like below -15C) I just turn off the Sanyo and use a backup.

davranyou · 01-19-11, 02:41 PM

So these air heatpumps likely consume greater amounts of electricity the more the temperature drops? And puts out fewer BTUs as a result?

strider3700 · 01-19-11, 04:04 PM

yes, they have to work harder to collect what is available as that amount decreases. Eventually they hit a point where they are using more energy then they are collecting so it's not worth running. Where that point is depend on the model plus a bunch of environmental factors.

Xringer · 01-19-11, 04:13 PM

You can't use the heating mode on the Sanyo, if it gets too cold..

But, around here, the 'average' really cold day is about -5 C overall.
http://pics2.city-data.com/w1q/lhaq11355.png

As you can see from this chart, -5 C still puts you at about 22,000 BTUs.
If I leave it set for 21 C, it normally uses about 500w.

This table shows the power use from 290w to 2490w.
The specs are a general guide. Mostly your power use will depend on your
indoor set point temp, outdoor temp & dew-point and how tight your house is.
Do you have good insulation? Or high leakage?? Those things determine the monthly bill.

I never use 290 watts.. The very minimum is about 440 watts.
At 21 cents per KWH, that's about 9 cents an hour.

Xringer · 01-19-11, 04:49 PM

Quote:

Originally Posted by strider3700

yes, they have to work harder to collect what is available as that amount decreases. Eventually they hit a point where they are using more energy then they are collecting so it's not worth running. Where that point is depend on the model plus a bunch of environmental factors.

If it was zero C and I was still getting 16,200 BTUs out, and the Sanyo was using max power of 2.49kW..
That's still not bad..

Considering that a resistive heating element needs 2.49kW to make 8,446 BTUs..

It's interesting how resistive heaters are such a bad investment.
But, if I had one using 24 kWh a day, (1kW = 3412.142 BTUh)
and it was able to keep us warm during mild weather, for a mere $5 a day..
That's not bad at all..
Compared to sitting in the cold or burning a few gallons of oil..

strider3700 · 01-19-11, 06:22 PM

entirely true. I run about $80-$90/ month in the winter for heat pump heating, electric hotwater and everything else electric using the heat pump and wood stove. My buddy has a much newer better insulated walls and much tighter house but has electric baseboards and he runs $200-$300 per month. My woodstove helps a lot because it's effectively free since I pay about $30/cord when you include gas

01-19-11, 08:44 AM	#1
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Why dig?? Mitsubishi Electric Sales Canada Inc. - Air Conditioning & Heating "Zuba-Central is capable of heating efficiently down to -30°C and beyond." If you live in Canada that is..

01-19-11, 11:58 AM	#3
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	It's the global warming.. I've heard there might be a few decades of cooling before the global warming really kicks in. I've been cleaning up the wall of snow around my Sanyo. Luckily, we had a January Thaw and some rain to clean off the areas where we've been cleaning off the walks, driveway & parts of the roofs we can reach. I've got an old snow-rake, leftover from the days when we have solar hotwater panels. It's coming in real handy for keeping the gutters from being ripped off by the ice ridge. 40F today and back to the 20s F tonight, more snow Friday and below zero F this weekend. I think the Zuba system will work like most mini-splits, when the coil sucks in too much snow. It will preform a defrost cycle (while your house cools a little) and then kick back into heating mode. I find we can avoid some defrost cycles by shutting down the heat when the wind is blowing the snow and it's is really coming down. Once the worse is over, it can be turned back on. You just need some good backup heat in the meantime.

01-19-11, 04:13 PM	#8
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	Yeah You can't use the heating mode on the Sanyo, if it gets too cold.. But, around here, the 'average' really cold day is about -5 C overall. http://pics2.city-data.com/w1q/lhaq11355.png As you can see from this chart, -5 C still puts you at about 22,000 BTUs. If I leave it set for 21 C, it normally uses about 500w. This table shows the power use from 290w to 2490w. The specs are a general guide. Mostly your power use will depend on your indoor set point temp, outdoor temp & dew-point and how tight your house is. Do you have good insulation? Or high leakage?? Those things determine the monthly bill. I never use 290 watts.. The very minimum is about 440 watts. At 21 cents per KWH, that's about 9 cents an hour.

01-19-11, 10:21 AM	#2
davranyou Lurking Renovator Join Date: Dec 2010 Location: Grande Prairie AB Posts: 22 Thanks: 1 Thanked 1 Time in 1 Post	Can this thing extract heat from the surrounding area when buried in 4 and half feet of snow? Snowfall has been crazy this year!

01-19-11, 12:11 PM	#4
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	Interesting my heat pump just gives up and kicks on the back up at -4C it would be nice to go a little colder without needing that. Right now I just use the woodstove on real cold days though. For global warming insulation and lots of it is your best friend. We can probably expect brutal hot summers and brutal cold winters with some wicked storms thrown in for the mix. Last year our town has set a new record high and a new record low...

01-19-11, 01:04 PM	#5
Xringer Lex Parsimoniae Join Date: Feb 2009 Location: Woburn, MA Posts: 4,918 Thanks: 114 Thanked 250 Times in 230 Posts	The Sanyo is okay down to about -12C. It still puts out heat, but I'm not sure how many BTUs I'm getting per watt. I don't think it's all that much. When I see less than -10C in the forecast, I turn on the flow-through valve, to allow oil+PV heated water to circulate in the baseboards. If it's going to stay cold for a long time, I'll set the oil burner timer to kick in an re-heat the water. 30 minutes on for each 90 to 120 minutes off. If it going to be colder, (like below -15C) I just turn off the Sanyo and use a backup.

01-19-11, 02:41 PM	#6
davranyou Lurking Renovator Join Date: Dec 2010 Location: Grande Prairie AB Posts: 22 Thanks: 1 Thanked 1 Time in 1 Post	So these air heatpumps likely consume greater amounts of electricity the more the temperature drops? And puts out fewer BTUs as a result?

01-19-11, 04:04 PM	#7
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	yes, they have to work harder to collect what is available as that amount decreases. Eventually they hit a point where they are using more energy then they are collecting so it's not worth running. Where that point is depend on the model plus a bunch of environmental factors.

01-19-11, 06:22 PM	#10
strider3700 Master EcoRenovator Join Date: Dec 2008 Location: Vancouver Island BC Posts: 745 Thanks: 23 Thanked 37 Times in 30 Posts	entirely true. I run about $80-$90/ month in the winter for heat pump heating, electric hotwater and everything else electric using the heat pump and wood stove. My buddy has a much newer better insulated walls and much tighter house but has electric baseboards and he runs $200-$300 per month. My woodstove helps a lot because it's effectively free since I pay about $30/cord when you include gas