Stick with HVAC advice. You can transplant any size of tree if you've the money, space, and water.
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Duly noted.

I live in an apt and the crawlspace that houses my AC scares me. It doesn't work worth shit. Bug, you can take a look the next tme you are in town.

Oh yeah got to love them crawl spaces. Better than an attic this time of year where it is 200+

Crawl space? :spock:

Most apartments either have the units outside or on the roof. Either way though, you should have a maintenance guy that can look at it for you. No guarantees he knows what the hell he is doing though.

Interesting. In November my wife and I bought a house way bigger than what we need because we both hate moving and don't want to have to move when we decide to have kids.

I've had half the house shut down all summer; I was thinking exactly like Dave Lane is thinking. I guess that was a mistake.

Man I thought the same thing forever as well. It's hard to wrap your mind around the physics behind it.

I'm a bit surprised that's the only thing anyone took any exception to. I thought for sure someone would take me to task on recommending the cheap crappy air filters.

Well if it hasn't froze up by now you must have quite a bit of duct leakage or the refrigerant levels will not be quite right when you start using the whole house. Try opening all the vents and see what difference it makes. See if the house cools better. I know it will cool more evenly. But see if the system will stay off a little longer between cycles. See if you have a little better airflow not just out of the registers but see if your return grills where your filters are at catch more dust. At the return you can use a piece of paper to see how strongly it is pulling the paper towards or on to the grills. If you have a couple of thermometers put one on or as close to the returns as possible. Put another at one of the registers. This time of year you should have somewhere around a Delta T of 15. That is the temperature difference between the two. 14 to 17 this time of year. Anything out of that range will show that the system is not opperating properly.

Why that is one of the best pieces of info that you gave!
A person should change thier filters every month. But for the sake of your customers to recommend a pleeted high capture filter you HAVE to know how the system was installed. Because if the return duct is not sized properly or if the surface area of the return grill is not large enough a pleeted filter with a small amount of dust can be a huge restriction to the airflow.
Not to mention they are 5 times more expensive.

I do use the cheapest pleated ones over the winter since I run woodstove to heat my house and the dust from it is terrible. My furnace doesn't even run all that much and those things are filthy after just a few weeks.

Well that is good that you check and are aware. And that you are a heat and air guy you can fix your own stuff. If you tell someone or do something for someone else that costs them any money or break down you are the bad guy.
In this business you will either be a hero or a zero.

This is not true I have a 6" duct I move 1000 cfm through. It has an inline fan but you can move huge amounts of air through ducts if you want.

Are registers and vents synonymous?

I have 4 filters (2 for each a/c unit) in the ceiling in the hallway upstairs. Are these the only filters, or are there more in the ducting or near the units? The only ones I've ever changed are those ones in the ceiling.

I opened all of the vents today. It seems so counterintuitive to cool more of the house.

Those "large tree" transplants always fascinate me.

Feel free to share some stories. Is there a size that hits the sweet spot in terms of money and "worth it"-ness?

Dude you can think what you want but until you have been to school and educated yourself you will not understand. You can believe what you want but there is a huge difference between cfm and fps. You are moving are at 1000 fps but you CANNOT move 1000 cfm of air through a 6" round piece of duct.

fps = feet per second
cfm = cubic foot minute

When you mess up your system and it costs you 10k to replace it and they tell you that your duct is all blown apart and needs to be replaced for an addition 2500 to 3000. Maybe then you will understand.