Thanks again. I will leave this issue as is for now, bare narrow pipe for a configuration on a house just bought last month equipped with 'heat pump' which I never explored before.

About crooks in the HVAC business, the part that pisses me the most is the pushing to replace entire systems when the fault was only a bad capacitor, or a chewed control wire, or incapable of troubleshooting with brains a system with potential life of another 10 years because the $ales of new equipment brings them much more revenue. The cost of parts to bring back to operation a failure is most of times, a few dollars; seen as opportunity to wring wallets from naive customers.

The previous house I bought had a worn bushing in the air handler fan motor, not running. $60 new motor cured it. In the house I live, I removed a gas burner heating unit and replaced with an used 10 KW electric heating air handler. Been running OK since November; am happy with no gas bill/service.

The local friendly knowledgeable HVAC guy gave me three electric used air/heat complete units removed from service and I brought them back to operation for pennies. Told me : Go to my barn and pick all you want from that cemetery piles. They are going to be sold for metal maybe enough to buy pizzas for the personnel. Loaded whole units with spare control boards, motors, evaporators, heat elements, delay relays...

Later I showed up with the most tempting pizzas in town for the whole crew there. Everyone happy.

 

A couple of weeks ago I saw an A/C truck next door at the deaf guy's house.
He was saying, "You have a Freon Leak."
and I was thinking, "Right there at the steel filter/dryer which shouldn't have been installed because this was a whole new system 10 years ago".
Then he said, "$450 to install leak test dye."
and I was thinking, "Sixteen dollars for the dye if you're too lazy to get your sniffer out and check that filter/dryer."
Then he said, "It's ten years old. Probably needs a new evaporator coil for $1200. Too expensive to repair."
and I was thinking, "The whole air handler only costs $900."
Then the deaf guy said he didn't have most of $500 for a leak test. Certainly not $1700 for a leak test and a repair when a new air conditioner would cost $2000.
So, there it is. A minor leak turned into a $2000 sale. Buy the whole thing new or do without.

The pirates around here basically mortgage your home back to you for any repair, no matter how small.

And while we're on the subject, heat pumps always contain a steel filter/dryer, or two. They rust out every 7 to 10 years.
A regular air conditioner doesn't contain any steel parts that Freon flows in.
No steel, no rust, no leaks, no ransom.

 

The pirates around here basically mortgage your home back to you for any repair, no matter how small.

About 10 years ago, I was having problems with my then 30 year old oil furnace. The guy who normally serviced it for us told me it needed to be replaced. He quoted me $13K cash to replace it; 3% more if I charged it on a credit card. AC would be another $13K.

I asked him if he could cobble it together so I could get through the heating season and he said no. It couldn't be repaired and had to be replaced; take it or leave it. I left it and was lucky to find another furnace guy.

The other guy came out, cleaned it, and got it working again. It has been working ever since and the current guy said there's no point in replacing it because it's running at nearly the efficiency of a new one. He estimated that the cost to replace heater and AC would be less than what the other guy quoted for furnace alone.

I saw an advertisement for an electric furnace with AC for less than $5K. Haven't decided whether I'll go electric or propane when I really need a new furnace.

BTW, heard on the street that my first furnace guy had ripped off a church by replacing things that didn't need to be replaced. I wonder how many times he ripped me off before I found an honest repairman... Where I live, getting ripped off by repairmen comes with the territory.

 

Haven't decided whether I'll go electric or propane

Personally, I don't like flammable fuels. Probably because I know enough about electricity to know if my house is safe from bad workmanship. Oil is messy and smelly, and coal is worse. Flammable gas might develop a leak, but electrical connections in a proper box can leak all they want and only pop a breaker. Of course, I have the good sense not to run extension cords under rugs or let wire nuts stand around where everybody can see them.

When you're installing an electric furnace, you need a wire for the air conditioner anyway, so you just make the wire 6 gauge instead of 12 gauge. No leaks, no spills, no odors. That is my personal opinion.

Of course, if you're installing an air conditioner, you have to be able to make pipe systems good to 450 PSI. If you can do that, you can pipe propane from a tank. I just find the second pipe, "one more thing to do". One more roll of copper, one more routing plan, and one more pipe to guard against injury.

Maybe I helped you organize your thoughts.

 

Turns out my daughter's new A/C is sized appropriately according to the chart here:
https://asm-air.com/airconditioning/what-size-central-air-conditioner-for-my-house/

It's just physically large – 51" high – to achieve good efficiency numbers, SEER = 17.0.

My coolant tubing is only insulated on the big tube. The little tube is naked from where it enters the house all the way to the evaporator coil above the furnace.

 

It's just physically large – to achieve good efficiency numbers, SEER = 17.0.

My coolant tubing is only insulated on the big tube.

Told ya' so and told ya' so.

 

Hi. Seems like dedicated to #12...

About efficiency; how can these systems be claimed as more efficient in winter; if a kilowatt is a kilowatt. The energy of the compressor, fan, remnant heat in coils/pipes is vented outside in the cold warming the ambient; say those items dissipate 1 KW. Instead, a 1 KW electric heating element inside would not waste anything outside.

Some heat-pumps have a blanket over the compressor, although those are there more to ensure smooth starting during cold temps (crankcase heater). As for the coils, in winter they are actually absorbing heat from the ambient air. Google : Latent heat.

Is this 'heat pump in winter' a good efficient idea?

Yes. Down to about -10 deg. C. for most units

Shouldn't the liquid refrigerant pipe running bare by a crawling space be insulated in winter ?

Absolutely. You want every morsel of heat to be conserved so that it can be dissipated within the air handler. Mine are insulated from the point they exit the outdoor unit right up to the air handler.

 

The heat lost in those small lines is insignificant compared to the overall heat transferred. The reason lines are insulated has to do with sweating, when the line is below the condensation point at the relative humidity in the area. These lines can condense a lot of water (like sweating on the outside of a glass of ice water) and that can drain here and there causing splotches on sheetrock, mold, and such.