In an apartment building, installation is going to cost you more than the actual unit. You need to run fairly heavy hoses to the condenser. You also aren't going to put a fleet of little one-ton units on the roof, so you're looking at much larger central condensers or possibly cooling towers for chilled water (which often ends up cheaper for large installations but requires more space).
Small installations are pretty simple if you can run the electric yourself. Then just hire an HVAC tech to purge the lines and fill to manufacturer specs. Done. Complex installs with multiple head units per outdoor unit get complicated as you have maximum and minimum line lengths and the length of installed line impacts amount of refrigerant needed and such, takes a good bit of planning and knowledge.
Contractors typically/frequently install AC condensers and furnaces that are too big for the house. These cost more and the contractors don't have to worry about call-backs for insufficient cooling or heat. Unfortunately they are much less efficient because they run for such short cycles.
Yeah so basically the guideline here is 25 btus per sqft, which is 270 btus per m2, house is 110ish m2, so it’s roughly 30k btus. So then get a 30k btu condenser, about $3400, plus three 12k air handlers ($600 each or so), plus labor and the rest of the random parts. Could be overkill, I’m just following guidelines for the estimate.
My NYC co-op is going through this now. All of your guesses are basically right. We're having separate systems installed for replacing in-unit hot water and in-unit heating and cooling. I believe the new electric hot water system is being installed in the basement and the condensers for the in-unit control panels are being installed on the roof and routed through the pipes used by our old radiator system.
Pros: units can control their own heat and will no longer need in-window A/C units. Cons: it's really expensive, even for a building with good finances and access to reasonable financing options.
We're only doing this because our boiler is probably a few years away from failing already (it's well over 50 years old), and we're super close to the building size threshold where we would be fined for not complying with the law (so any adjustments to how they calculate building size or dropping the law's fine floor would certainly push us over).
I was a bit surprised he bought two condensers instead of one large one.
I’m looking for a mini split currently and I found condensers with up to three separate coolant lines (although with the shape of my place. I might only be able to use 2 at once, and have to use a window unit on the other end).
Unit size (especially width) goes up much slower than BTUs, so the main value of two seems to be cooling your house in installments, which he isn’t doing.
Most residential units match one outside compressor to a single interior evaporator because to use one exterior unit for both you'd need way more complex valves to control which unit is receiving cooling.
Even if your matching one to one you have the added cost of running all the lines associated with that including having a trades person coming out to install and charge the extra piping between the two units and installing the exterior unit that will need power. It's just massively simpler to have a complete unit you can drop down and optionally connect to water.
> With new builds air to water makes sense as it’s no different to installing any type of central heating system.
But it's the same level of effort than installing indoor A/C units, so why not install those instead? Plus refrigerant pipes can potentially be thinner depending on the max "load" of that room.
The installation of such hardware is difficult. You do need a plumber and people that rent their home probably can't do it without the landlord's consent.
Why not rather focus on the central heating of buildings?
Look into and get a split-unit ac. You can run the pipes quite a long distance, more than the advertising material and stock images would have you think! If power is cheap, you’ll regret not doing ten years ago.
Pioneer had the best bang-for-the-buck the last time I checked.
I used to live in a building that had an electric furnace in each unit. The air conditioning coils were connected to a condenser shared with the building; the size of the piping led me to believe it might be pushing chilled water (vs. refrigerant) to each unit. No crappy boxes hanging outside, individual per-unit control inside.
Your argument is mostly right in terms of what would be required (the super-high efficiency filter is not necessary, nor are attic fans, to achieve anything interesting), but actually, you have to have multiple condensing units past a certain point.
It's simply not efficient, even with auto-closing dampers, to zone and duct a multi-zone system with single condensing units.
You'd be much better off, efficiency wise, either:
1. Using mini-splits everywhere.
2. Going geothermal. You can support multiple units off a single loop. I did this in maryland. My 4000 square foot house had all the hot water and cooling provided by GSHP. My energy bills, keeping it whatever temperature I liked, dropped from about 400 a month in the winter to about 50 bucks. The wonder of 41 EER, 5 COP. Unlike the air source heat pumps, they actually publish real efficiency curves for various temperatures, and your pump actually work at close to expected efficiency!
I don't think the hardware is that expensive in the US, it's the installation (which costs more than the hardware).
And mistakes by installers will cost even more. Our installers didn't flare a line set connection properly and it leaked slowly and that was a very expensive bill (especially since refrigerants have changed so much).
Our Daikin indoor units have also had condensate leaking issues, probably due to poor installation.
Ductless heat pumps do seem like the future but I think there are issues with regards to condensate draining, air filtering, and indoor unit cleaning/maintenance and replacement that could be done much better.
> you can expect to pay $2000+ to install on top of that, depending on how hard the job is.
Installing a mini split is nowhere the difficulty of an HVAC though, assuming your have the electrical circuit (which I'd guess would be an electrician's job not HVAC) it's a few hours' work, at least for a simple case and if the installer knows what they're doing: pierce the wall, mount the external unit, mount the internal unit, connect the two, charge[0], done.
By "simple" I mean a 1:1 setup with both units mounted on the same wall (and a wall-mounted indoor unit). Obviously a more complicated setup (multi-zone, slim duct, more distance between the two units) would take more time and be more expensive.
I can see $2000 for a non-trivial multi-zone setup.
[0] if you're handy there are mini-splits sold specifically for DIY installations which come pre-charged, though that means the pipes won't exactly fit the distance I guess
It probably helps quite a bit, especially when a lot hotter outside than in. (But that's often not the case where I live south of Seattle.) But when I move to IL, I'm thinking mini-split is much easier solution for 1-2 room apt.
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