Heat Pumps in Life in General

Tomorrow we’re having a new air conditioner installed at our home. The cost is insane but I’ve always wanted a inverter heat pump air conditioner and this was my chance.

Our current unit still works but it’s 13 years old and doesn’t really keep up with peak summer heat. I tried servicing it and that didn’t help much, on a 105F day the inside temp would still creep over 80F. I had a couple techs check the unit and they both confirmed the compressor was drawing too many amps… aka it is failing.

It didn’t surprise me much the home inspectors also noted the unit was old and wasn’t performing well. I was just hoping servicing the unit would help. Oh well.

Some AC nerd stuff.

Most AC units are single stage (either on or off). They are cheaper to make this way and work fine, but during mildly warm days they do something called “short cycling”, meaning they only turn on briefly and then switch off.

Which doesn’t affect the cooling performance but it does impact dehumidification, which is the secondary function of your AC. That’s because during short cycling, your AC doesn’t stay on long enough to cycle all of your indoor air, so it can’t dehumidify properly.

If you’ve ever noticed that for some reason in the spring/fall you’re setting your temp lower than you would during peak summer, high humidity is the likely culprit.

Okay so now inverter AC units. They can operate anywhere from 30-100% power. So your AC actually rarely shuts off, just lowers down the power level to match your heat load. And the longer your AC is on, the more air it can cycle through and dehumidify… hence the lower humidity and better comfort.

Also since it never shuts off, your temperature is more stable… rather than bouncing up and down as your single stage unit powers on/off. So yeah a lot of advantages… but the biggest disadvantage…

Cost. It’s roughly 50% more expensive than single stage. Even with the energy savings over time, it’s probably never going to offset the upfront cost. So the reason you do it is mostly for the added comfort and the lower noise level.

They do have cheaper two-stages that are a middle ground option. But if I want to add zoning to my house (controlling individual room temps) I have to have a communicating system… and guess what… that’s inverter only.

Also I’m swapping our gas furnace over to a heat pump system. Gas is really powerful and can heat your home super quickly, but it’s just not necessary in Texas. It doesn’t get cold enough for long enough here. A heat pump is perfectly fine for this area, and it’s cheaper to run than gas (until a certain outdoor temp, but again, that doesn’t happen here often). Everyone here is raising their eyebrows at me like I’m crazy for getting rid of gas (because 99% of people only get heat pumps when they don’t have gas available) but I don’t care, I know what I’m doing.

More AC nerd stuff.

For those who don’t know what a heat pump means, it’s technically a misnomer. Every AC system is a heat pump, but they typically only operate in one direction… remove heat from inside and “pump” it outside. But in my case, mine will operate in both directions. AC coolants boil at super super low temps, typically around -60F, so even if it’s 30F outside, that’s still 90F hotter than the boiling point.

Basically, even when WE think it’s cold outside, from the coolants perspective, there’s still PLENTY of heat out there to boil and pull heat from the air. So it pulls heat from outside air, and pumps it inside, warming your home.

And since it’s not CREATING heat (like electric heat strips and gas heat does), only MOVING it (or pumping) from outside, it operates 3-4x more efficiently than normal heating. That is… until a point. The colder it is outside, the less effective it gets… to a point where it can’t keep up with your heat loss. That’s why they install backup heat strips to help on super cold days (usually called “emergency heat” on your thermostat). But again, in Texas, there may only be a few days out of a year that happens. So I’m not too worried about it.

Okay, no more AC nerd stuff (he lied). I’m super excited to see it installed. I’ve never seen an inverter AC system in operation before so it’ll be really cool to have it here!

More AC nerd stuff (kinda)

So of course the long term goal is to get all of the gas out of the house. When we moved in, the previous owners already did us a favor and installed an electric stove/oven. So with the gas furnace gone, the only two things left will be the water heater and the fireplace.

Now the fireplace is no big deal. Sure, gas makes the fireplace easier to light, but you just need some kindling and you’re good to go without it.

But the other thing, the water heater, is a bigger deal. Electric water heaters are WAY less efficient than gas heaters… usually costing about twice as much in energy (depending on where you live of course). Now you may think “well I guess he’s keeping his gas water heater forever”.

NOPE. guess what else they have!?!?!? HEAT PUMP WATER HEATERS WOOHOOOOOOO. haha.

Yeah so it’s basically just a small AC unit strapped on top of a water heater. And just like with the home heat pump, it pulls heat from the surrounding air and puts it into the water. Side benefit is that it cools and dehumidifies the space its in, so if you’re in Texas like me, it will cool down your garage (or whatever else room it’s in).

And these things are EFFICIENT AS FKKKKKK. Only using about $10/month in electricity on average. That’s because, again, they don’t MAKE heat, only move it from the air into the water. Now the downside is they have a longer recovery time (meaning if someone in your house takes 90 minute showers it will take longer to get that hot water back). But they also have regular heat strips to help the heat pump out in high demand situations (just like a home’s heat pump actually!), so it’s not really that big of a downside. And many people just get a slightly larger tank to offset it as well.

My plan was to wait for our water heater to kick the bucket but I went to drain it last week and check on the anode rod, only to find the anode was never ever replaced.

Side note… if you don’t know what that means… go look up “anode rod replacement” on youtube and check yours. It’s a pretty easy job if you have a couple of common tools. They keep your water heater tank from rusting and only cost about $50 every few years to swap out. So instead of your water heater only lasting you about 10-12 years, you can get 20 years out of it.

Okay, anyway, so I got to check mine and the anode is just gone.. nothing left. And the tank is completely rusted out, horrible. It’s just a matter of time before it starts to leak. So guess who is getting a heat pump water heater soon (and also disconnecting his gas service)?!?!?!?!?!

This guy…