Snow storm

[Jjrss]

Thanks. We already have a relatively new (5 years old) high-efficiency heater that has multiple stage outputs. But if we need to replace this in the future I will consider a heat pump.

I hope they blow warm air these days. My previous homes that had heat pumps blew air that was about the same temperature as the setting, and I did not like this.

Ive been testing mine recently, at 40 degree outside temp, the register vent temps were inside-temp + ~20 degrees. Example: I like my home around 72, came home to 66 degrees (Nest "away" feature dropped the temp). Registers showed a range of mid 80s at the start and mid 90s near the tail end of the heating cycle.

When temps were in the mid teens, I relied heavily on the LP furnace to overcome the same low drops (much faster), but then switched to the heat pump to maintain.

I actually ran out of propane this last week as I'd just bought the place in October and the 250 gallon tank was only about 20~30% full. Heat pump has been keeping the house right at 72 without any issues. Outside temp ranging from low 30s to 50s. Throughout the week.

Further research I've discovered the Nest "smart" features are competing with the Bosch Bova 2.0 heat pump "learning" stuff... I've since turned off all the Nest features and might be getting the Bosch BCC100 thermostat instead.

There are lots of dipswitch feautures on the heatpump as well to increase on demand heating capability and mulitple stages, but I believe my installer configured it to use the Furnace for high demand and below 40 degrees for efficiencies.

 

[Johnny Vector]

Thanks. We already have a relatively new (5 years old) high-efficiency heater that has multiple stage outputs. But if we need to replace this in the future I will consider a heat pump.

I hope they blow warm air these days. My previous homes that had heat pumps blew air that was about the same temperature as the setting, and I did not like this.

My not-quite-5-year-old Mitsubishi mini-splits blow a nice comfortable temperature of air. I haven't measured, but I would guess about 120 °F. (50 °C.) They're also essentially silent (27 dBA) on lowest fan speed, and quieter than any ducted system I've had until you get to fan speed 5, which I've never used. The outdoor units are also barely audible. In my case completely drowned out by my neighbor's Trane or Carrier or whatever she has.

 

[jboy210]

My not-quite-5-year-old Mitsubishi mini-splits blow a nice comfortable temperature of air. I haven't measured, but I would guess about 120 °F. (50 °C.) They're also essentially silent (27 dBA) on lowest fan speed, and quieter than any ducted system I've had until you get to fan speed 5, which I've never used. The outdoor units are also barely audible. In my case completely drowned out by my neighbor's Trane or Carrier or whatever she has.

I don't think I would go with mini-splits because of the cost of running the plumping and units. I would probably just do the swap of the current heating unit. But one of my children had mini splits in her apartment and liked them.

 

[Jjrss]

I don't think I would go with mini-splits because of the cost of running the plumping and units. I would probably just do the swap of the current heating unit. But one of my children had mini splits in her apartment and liked them.

You can always stack them together and run Dual fuel.

The home I bought, came with the 1 year old LP furnace. They kept the same furnace with my install.

 

[Johnny Vector]

I don't think I would go with mini-splits because of the cost of running the plumping and units. I would probably just do the swap of the current heating unit. But one of my children had mini splits in her apartment and liked them.

Yeah, mini-splits are most optimal for new construction or retrofitting a house that doesn't have ducts (e.g. my previous house which had radiators for heat and window units for A/C).

But! The other part about mini-splits that makes them efficient, besides their split-ness, is the vari-speed scroll compressor. And you can get traditional central units with those. The big advantage there is that you can size it large enough to handle your coldest/hottest temperatures but not have it oversized during the spring and fall. Also scroll compressors are much much quieter than the old-fashioned reciprocating kind. And more reliable too, I think. The modern kind cost more up front, but pay back in increased seasonal efficiency over their lifetime. Also keep you more comfortable, because of that not-being-oversized-half-the-year thing.

And now we're so far off the original point of this thread that it should probably be moved to a new one. Or, really, a whole different forum. Sorry!

 

[Jjrss]

Yeah, mini-splits are most optimal for new construction or retrofitting a house that doesn't have ducts (e.g. my previous house which had radiators for heat and window units for A/C).

But! The other part about mini-splits that makes them efficient, besides their split-ness, is the vari-speed scroll compressor. And you can get traditional central units with those. The big advantage there is that you can size it large enough to handle your coldest/hottest temperatures but not have it oversized during the spring and fall. Also scroll compressors are much much quieter than the old-fashioned reciprocating kind. And more reliable too, I think. The modern kind cost more up front, but pay back in increased seasonal efficiency over their lifetime. Also keep you more comfortable, because of that not-being-oversized-half-the-year thing.

And now we're so far off the original point of this thread that it should probably be moved to a new one. Or, really, a whole different forum. Sorry!

Or, just get a variable speed inverter heat pump like the Bosch Bova 2.0. Scales as needed

 

[Johnny Vector]

Or, just get a variable speed inverter heat pump like the Bosch Bova 2.0. Scales as needed

Yes, that is an example of the variable speed scroll compressor type system I was talking about.

 

[Jjrss]

Yes, that is an example of the variable speed scroll compressor type system I was talking about.

I think the only real reason to do mini splits outside of a remodel is either a Tine house, or multizonal heat/cooling. Otherwise tap into your existing ducting at the existing furnace with a hydronic coil.

 

[WADan]

Yes, the Tesla heat pump is designed for cold temperatures. That's why it has a dual stage system (to perform well in sub-zero conditions). The recent problems experienced at -30 F up in Canada were mostly due to the louvers on the front grill being frozen open allowing that -30 F air to blast the system.

Our house (5000 sqft) actually has two heatpump units, and they switch from the heatpump to auxiliary heat (ie. the furnace) around 40F. We did not have a heatpump before, so I am still learning about them.
One thing I don’t like is that they are pretty noisy, and I don’t know why the smaller one is significantly noisier than the big one even though they are from the same manufacturer (Bryant).

 

[StealthP3D]

Our house (5000 sqft) actually has two heatpump units, and they switch from the heatpump to auxiliary heat (ie. the furnace) around 40F. We did not have a heatpump before, so I am still learning about them.
One thing I don’t like is that they are pretty noisy, and I don’t know why the smaller one is significantly noisier than the big one even though they are from the same manufacturer (Bryant).

Do you have central heating with two heat pumps or two mini-splits with multiple heads?

I've found the mini-splits to be very quiet which is important at my ski cabin because there is no road noise and very few other sounds to mask whatever small sound the mini-splits make. I am super pleased with how quiet my Daikin is. I've never had a domestic unit like Bryant (I think they are now made in Mexico) but my impression is they are not as finely tuned and engineered to be quiet and efficient, at least not to the same degree as many of the Japanese brands.

Mini-splits became very popular in Japan decades before the US so I think the Japanese brands just have more experience making them. It may be they value things like quietness and efficiency more than most Americans who seem more interested in getting a "deal".