One other thing... I'm naive about heat pumps... Some friends/neighbors reported that their heat pumps continued to run the outdoor unit even when it was approaching zero outside. When they had electricity their houses struggled to get warm - just warmer than outside but not exactly 'warm' w/ their heat pumps. They believed what heat they had was from their aux electric heaters in the heat pump...

If so - why would a heat pump continue to try and run at all at such low temps? Should their not be an outdoor temp sensor and the logic board simply stops running the compressor below a certain outside temp? And rely solely on the aux electric?

Whether the compressor is locked-out from running below a particular ambient temperature depends on the capability and options provided by the control system.

I had/have heat pumps in both of my houses. The first wasn't originally, I changed it after 10 years (sold/moved 4 years later). Current house already had one (17 years now). The compressor on both runs/ran with the auxiliary, unless I manually set the mode to Emergency (which locks-out the compressor by intention). It still generates heat, just needs help from the auxiliary to meet the load. H-o-w-e-v-e-r, I may set it to Emergency in some weather situations such as near/at/below freezing with rain/high moisture that causes heavy frosting, being that it's a builder-grade unit with timed defrost that may not handle such weather very well.

I'm in TX, couple hours from further S/W from Houston. Just to say, gas central heat won't work in a power failure unless there's a way to provide power to it for running the controls, burner igniter, and indoor blower.

I would say it greatly depends on where you're building in Texas. Natural gas is still the predominant pick here. If you're more rural, then yeah propane or heat pump with electric strip back up / emergency and in some cases just electric strip only.

Heat pumps have come a long way over the last several years. But in colder weather the cheaper models performance drop off a cliff usually somewhere in the 20 degree range or so. As they often spend more and more time in defrost under those conditions.

What recently happened with the freeze: most didn't have heat anyway. Weather gas or electric you still need power. I know you say you have a generator but most do not have those.

The freeze was hopefully a one off event not to be repeated for 10 or 20 years. It doesn't get that cold here that often (Katy, Texas Area). 2011 was last time, before that it was like 1989 or something like that. That said this last time wasn't the coldest ever recorded temp. That was 5 degrees set on Jan 18, 1930.

Heat pumps work by pulling heat from outdoor air (cold air) then taking that heat from that cold air and pumping it indoors. As temps fall (outside) there is less heat. Also below freezing any moisture in the air will freeze on outdoor coil making it harder still to extract that heat.

Then if the heat pump enters defrost it is now running in ac mode making the indoor coil "cold" if back up heat strips are inadequate / improper set up for "really cold" weather that we rarely get here.

Would you want to pay "extra" for something you might never use?

I've had discussions with people that decide to stick with strip heat only because they don't want the extra expense to install a heat pump. Even though the heat pump can save you upwards of 75% off what it typically costs you to run strip heat.

Just a couple of chilly winters here can make up that cost versus strip heat. Propane is probably similar. But many a winters... it's like 2 weeks and gone or sporadically over a month or two.

So heat pumps are still quite the debate. I have an Inverter heat pump at my house. Those aren't for everyone... it's a choice. I bought it more for what it does on the AC side of things rather than heating.

It's often more of a challenge to keep things cool here. It also does a better job of dehumidifying.... which for my neck of the woods in Texas is the other elephant in the room.

I would suppose that the electric grid in Texas will get some reforms after this event. Maybe wishful thinking....

You can probably run a heat pump just fine with a generator - you just might plan a slightly larger generator.

What we do in NC for many is a fueled fireplace that works with no power at all (battery start). Then no generator and enough heat for the occasional ice storm.

I suspect in Texas, propane is as expensive as electric resistance. A heat pump is kind of a no brainer. (without access to NG).

Your heat pump will often work better than an electric strip (ie cheaper) down to about zero but that temp varies based on model. It makes no sense in Texas to get a heat pump that is good for really low temps so most that you would see don't do well at that temp. They often still try with aux assisting. Easy enough setting on most modern thermostats.

I can't imagine it is worth getting a hybrid unit with propane. Added install cost and complexity. Only makes sense in expensive electric markets.

It makes no sense in Texas to get a heat pump that is good for really low temps so most that you would see don't do well at that temp.

Not true. Because of Air Conditioning mode. The HP's that perform at really low temps are also more energy efficient, better dehumidification in AC mode. (Inverter)

That said there is more to this subject than just this point alone. Comfort means different things to different people.

I assume NG service is not available. What is your Electric rate and cost of propane/gal?

TD

Follow-up answers...

Power @ current home runs about 13 cents KWH. New homesite - different company - everything seems to run higher there it seems. (I woudn't be surprised if rates increase generally in the state in the coming year)

Propane is more variable, runs about $2.25/gallon give or take 25-50 cents based on prices I've paid in past 15 years.

As stated above, no NG. Will have in ground LPG tank anyway for cooking and water heater.

Current home is 20+ years so expect newly constructed home to be better insulated overall against cold (and heat). If it matters will probably end up w/ 2 HVAC units due to the long/skinny length of the home.

Have a portable generator that will easily run our current propane furnace (the only real draw is the squirrel cage - maybe a whole whopping amp or 2). I would assume a heat pump alone to draw significantly more amperage for the compressor and if the strips are cooking - even more amperage still. I don't have any specs but that might push the limit of even a larger portal generator and into a standby generator territory...

thanks

You have a pretty good overview based on previous comments. Food for thought by a fellow Texan with HVAC experience. I installed a two stage t-stat outdoors that pull's in 1 resistant strip at 30F, then disable's compresser and switche's to total resistant at 25F which I arrived at through tests and calculation. As mentioned above,the number varie's by mfgrs. I have a free standing decorative propane heater with ceramic logs. We injoy the heater on special occasions and it served well during recent power outage. I grew up with and many people around here still have ventless propane heaters but I chose vented and installed a scavenger in vent pipe. So as you see,I chose all electric eventhough I can but hybrid equipment at wholesale and self install. The most valuable advice I have is that when it come's to level of proformance and life span, installer is far more important than equipment. I believe when A Air said inverter isn't for everyone,the point is there is no use spending extra money for state of art equipment then alow trained monkeys to install it. Builders often employ the lowest paid installers they can find. High tech also requires certan skill to service.

I had both a daytime and evening job when I bought this current house. I did daytime setbacks on heat (setups for cooling). The thermostat has smart recovery that begins early of the programmed temperature change to avoid running the auxiliary but it sometimes wouldn't be within 2°F of it at the target time so would trigger the auxiliary, unnecessarily IMO being that running a half-hour-ish longer would get there. I had an outdoor temp sensor added to the thermostat which allows setting an ambient lock-out temp above which the auxiliary can't run (except during defrost or Emergency). I set it at 25°F which effectively makes for no auxiliary under "normal" conditions and never have a problem with the system maintaining 70°F. I recall one season a cold/dry norther was 22°F so I reduced the lock-out to 20°F. There has been maybe 3 or 4 times over the 17 years that I went to Emergency mode for frosty/snowy/icy situations, including the Feb 2021 situation.

In Austin County. We have 'some sort of 'auxiliary' or 'extreme' or 'emergency' setting on the central heat system (which, incidentally wasn't working well during the mid Feb storm). What DID work well was a propane space heater ($100-200 on Amazon) utilizing the small propane bottles designed for a bar b q pit. We ran the heater non-stop for a week, used up 2 of the bottles ($20 to fill each one) and were quite comfortable. the heaters are much safer than in the past; two family members purchased one just for future problems after having no electric power for many hours (so heat pump didn't work at all). Check out Mr. Heater brand.

I believe when A Air said inverter isn't for everyone,the point is there is no use spending extra money for state of art equipment then alow trained monkeys to install it. Builders often employ the lowest paid installers they can find. High tech also requires certan skill to service.

yeah that's as good a reason as any. There's much more than that though when it comes to inverter AC's / Heat pumps. Especially in the build a new home category.

If you can believe it, I signed a short 6 month term electric contract in Jan. 2021 for a bit over 6 cents per KWH.

My electric bill this month is around $25 or so. LOL. I doubt I will find such a low rate to renew at. I knew I was kind of gambling with that short contract. The longer contracts at the time were a shade north of 11 cent per KWH.

If I still had the old single speed clunker AC the bill would probably have been closer to $50. (so you mean I am going to spend this money to save $25 a month? --- so that's the other reason when electric rates go cheaper.)

Comfort and the views of people. Even when you tell them this will provide you with "better" comfort. Some people will never see it that way. That's why it's not for everyone. It's a choice.