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Home Office Projects Series: Air conditioner setup

techprowd.com

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Re: Home Office Projects Series: Air conditioner setup

#61

Post by baq »

dpeck wrote: post #41
7thaccount wrote: post #7

Earlier quoted context omitted.

In Louisiana and Arkansas (probably several other states), the temperature can get over 100 Farenheit with super high humidity. This leads to "swamp @$$" without copious amounts of AC. Being comfortable requires AC in the home, car, and at work. In highschool gym class we would just sit in the shade under the bleachers during the summer (too hot to do anything) and be dripping sweat everywhere back in class. It was m…

As much as A/C is amazing, it’s the lack of moving air that makes me the most uncomfortable. I’ve always been surprised at how much of Europe seems to have no interest in fans, ceiling or otherwise.

at my latitude wind blows from the west 80% of the time. i can count windless days in the year on my fingers.

Re: Home Office Projects Series: Air conditioner setup

#62

Post by lxe »

I just did a DIY install of a mini split AC, including running electrical and the refrigerant lines, having never done so before. There was a whole "hidden side of the iceberg" to learn besides just the controller parts of how it works. The unit cost was ~600 while the install would have been ~1500, so I was betting that if I mess up catastrophically I could replace the whole thing once or even twice.

Re: Home Office Projects Series: Air conditioner setup

#63

Post by L_Rahman »

rsync wrote: post #24

Having individual heating and cooling units ( per unit gas heaters! ) is stupendously inefficient. I travel in Asia fairly regularly so this isn't new to me, but even after all of these years I can't believe I continue to see shiny, brand new "high end" condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC units hanging out the window. Contrast this with a condo in Minneapolis that I own wher…

This examples fails to account for the fact that radiant floor heating is a default feature in all new Korean homes.

Re: Home Office Projects Series: Air conditioner setup

#64

Post by tantalor »

Spivak wrote: post #40
rsync wrote: post #24

Having individual heating and cooling units ( per unit gas heaters! ) is stupendously inefficient. I travel in Asia fairly regularly so this isn't new to me, but even after all of these years I can't believe I continue to see shiny, brand new "high end" condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC units hanging out the window. Contrast this with a condo in Minneapolis that I own wher…

Whole building climate control isn't really the problem, it's that unlike electricity, there's not a good billing system attached to it like we have for eletric and gas. Other than "it doesn't exist yet" there's nothing fundamental about central air that precludes being able to bill individual units separately based on their usage. The fairest way for a group to pay for something isn't always diving the total cost eq…

I doubt that. OP said "individual units can set their temperature to whatever they like"

This implies they can turn on/off their usage. So you can install one electric meter per unit, which equally distribute the current load on the A/C, and turn the meters off (increasing load on other meters) when that unit is not consuming A/C.

Re: Home Office Projects Series: Air conditioner setup

#65

Post by jcrawfordor »

Scoundreller wrote: post #42
pwg wrote: post #18

Earlier quoted context omitted.

> Where are the refrigerant lines, how did they run them from compressor to evaporator? Look at this image from the blog post showing the post install view: https://www.techprowd.com/content/images/2020/09/image-24.pn... Notice on the left edge there is a large white "pipe" running from the evaporator unit down to a hole in the wall (the hole was already present and visible in other photos). The refrigerant lines are…

> refrigeration grade vacuum pump needed here My understanding is that some of the DIY units had a built-in vacuum pump for this step. Edit: never mind, I think I’m making stuff up in my head. But I could see it being a feature in the future. What makes a vacuum unit “refrigeration grade”? Other than recovering what you’re vacuuming if you’re doing maintenance instead of a first install?

Rated to pull high vacuum, <500 micron at the most. You can get such pumps very cheaply, the issue is usually the volume on them - when I tried using a very cheap ($60) one it took a very long time and kept going into thermal protect on the way down, and that was with a small system. Refrigeration techs use vacuum pumps that both move a large volume and can do very high vacuum and that's pretty expensive, although not insanely so - I see one from a popular HVAC brand for $500.

Re: Home Office Projects Series: Air conditioner setup

#66

Post by driverdan »

gcds wrote: post #32
rsync wrote: post #24

Having individual heating and cooling units ( per unit gas heaters! ) is stupendously inefficient. I travel in Asia fairly regularly so this isn't new to me, but even after all of these years I can't believe I continue to see shiny, brand new "high end" condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC units hanging out the window. Contrast this with a condo in Minneapolis that I own wher…

I think it's more efficient to heat/cool single room than all house when for e.g. you spend most of the day in office/living room and then go to bed. That way you only have one AC running but of course if you have big family then it maybe makes sense but still... Those mini split AC efficiency is much higher than I have seen in US ducted systems (follow few channels) because mini splits uses inverter technology for h…

With a central chiller you can still have each room on a separate zone.

Re: Home Office Projects Series: Air conditioner setup

#67

Post by quickthrowman »

marcinzm wrote: post #55
rsync wrote: post #24

Having individual heating and cooling units ( per unit gas heaters! ) is stupendously inefficient. I travel in Asia fairly regularly so this isn't new to me, but even after all of these years I can't believe I continue to see shiny, brand new "high end" condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC units hanging out the window. Contrast this with a condo in Minneapolis that I own wher…

>Contrast this with a condo in Minneapolis that I own wherein heat and AC are central in the building and individual units can set their temperature to whatever they like - all run with tremendously higher efficiency. Is it more efficient? There is going to be loss as things get pumped across hundreds of feet even with insulation. The central system needs to run even if few units or not units are using it just in cas…

Generally (in a high-rise) the units are fed a steady stream of ‘supply air’ at 50 F or so, and heat pumps in the unit itself control the climate in the unit.

HVAC needs to run constantly in these buildings as they’re sealed and need airflow for air exchange.

Air isn’t heated and then sent thru the ducts in a high-rise building.

Re: Home Office Projects Series: Air conditioner setup

#68

Post by driverdan »

gcds wrote: post #29
agwa wrote: post #26

Earlier quoted context omitted.

I've never seen an apartment building in the US with special pipes for running the refrigerant lines. It's just not feasible to install a mini split in the US if you're renting, but it appears Japan is totally set up for it.

Impossible to live without AC in Japan. Also almost every move company can remove/install AC's pretty easily so it's kinda convient. Also if all rooms already have installed AC's then apartment rent price is much higher than similar without it so it's 50/50 what you want.

> Impossible to live without AC in Japan

Come on. People lived there for thousands of years before AC.

Re: Home Office Projects Series: Air conditioner setup

#69

Post by zaroth »

lxe wrote: post #62

I just did a DIY install of a mini split AC, including running electrical and the refrigerant lines, having never done so before. There was a whole "hidden side of the iceberg" to learn besides just the controller parts of how it works. The unit cost was ~600 while the install would have been ~1500, so I was betting that if I mess up catastrophically I could replace the whole thing once or even twice.

Would love to read the write up!

Re: Home Office Projects Series: Air conditioner setup

#70

Post by mattdoughty »

rsync wrote: post #24

Having individual heating and cooling units ( per unit gas heaters! ) is stupendously inefficient. I travel in Asia fairly regularly so this isn't new to me, but even after all of these years I can't believe I continue to see shiny, brand new "high end" condo buildings in Hong Kong, Shanghai, Tokyo, Seoul, etc., with individual AC units hanging out the window. Contrast this with a condo in Minneapolis that I own wher…

I used to live in a flat (I guess you would call it a condo in the US) with heating provided by the building. My landlord who I lived with left the heating on 24/7 during the winter and the flat would get ridiculously hot. Even though he was the one paying for it indirectly through service charges. This arrangement is becoming quite common for new build flats in the UK but I would actively avoid if I was looking to buy.
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