Hacker News Reader

Comment by happytiger | Hacker News Reader

My buddy just installed a dc hybrid system and it’s been pretty much amazing. He’s in a warm climate with lots of sun though, but the idea of plugging panels directly into solar panels on hot days makes so much sense.

Are you in a cold climate? My biggest concern is installing splits in very cold mountain climates (my use case).

View on HN

Just installed mini-splits this autumn in the Seattle area and am living my first cold days now. What I found out is that insulation is very important. Parts of our house has very poor insulation. Coolth escapes in particularly from the floor. Our house is over a 100 years old with insulation retrofits from the 70s. I have a friend in the same area which has a new house with mini-split and modern insulation and hers works amazingly. We will definitely be working on retrofitting the rest of the house with proper insulation next summer.

Living in a cold mountain climate you probably have a pretty decent insulation.

Insulation is very important! I live near Portland in a fairly new construction and found my attic insulation is the bare minimum, currently planning to blow-in more soon. After running the numbers, between federal credits and heating savings it'll pay for itself within 2-3 years.

Could I ask who you used / what they charged? I got several estimates in 2021 and they were all pretty wildly high despite a very simple requested configuration. I'm curious to know if the market cooled (no pun intended) since then or if prices are just strictly increasing.

Sorry, my partner is a carpenter and did a lot of the work her self. She did get an HVAC expert to help with the installation but the price included some bilateral favors, friend discounts, etc, etc. So not only is the price hard to figure out, it is also not gonna be representative outside of our situation.

FWIW, Mini splits are very DIY'able. I was surprised to learn they don't cost much more than an air conditioner. In 2021, I bought and installed a 12k BTU for around $850. HVAC companies seem to charge an arm and a leg - my neighbor put a 2-head unit and I think they paid around 6k.

What brand did you install? MrCool diy seemed the easiest to DIY but my 2 zone install came to about 6k. Surprised to hear a condenser and air handler together could be $850.

Pioneer. I just installed a 2 head and it was about $2000 in total. They come pre-charged but require more work. You have to cut/flare the lineset and vacuum the lines.

The thing I don't like about MrCool is that you can't cut the lineset and have to coil the extra which is a bit janky. Also they have a considerable markup over other DIY.

I did research the DIY kits, though my biggest worry is that down the line I won't be able to find companies willing to touch it if it needs servicing.

Properly installed, there's not much to service. Watch a few Youtube videos on what goes wrong with heat pumps, and you'll learn that proper site prep is critical. ie the units must be level so the bearings won't wear prematurely.

I got several quotes in the Seattle area this past summer. The cheapest was 18k, the most expensive was 34k. These were for 3-4 zone installs.

I went with mrcooldiy and did it myself for about $7k.

> Coolth escapes in particularly from the floor.

Sorry, could you try that again? I cannot figure out what you meant.

Missed a comma.

Coolth escapes in, particularly from the floor

Coolth is the antonym of warmth.

Was the insulation being important realization related to the mini split install? Curious why that would be more noticeable with mini splits vs other forms of heat.

Capacity. Heat pumps are typically lower capacity (in BTU/hr delivered) than a fuel burning appliance and that capacity drops with very cold outside temps.

Sounds likely, however this is also my first winter—and my first cold sprout—with them, as such I’m learning which temperature to set it at etc. With our gas stove we usually set it higher on cold days, I guess with heat pumps we need to do that even more so.

Inverter drive heat pumps do well in a continuous and lower output situation, so the conventional wisdom (from gas fueled appliances, often with only 1 or 2 stage burners) to do a nighttime setback for economy is less useful economically. Set back for nighttime comfort if you want/must, but not (much) for economy.

The lowest I've seen for mini splits is -30 C in heating mode. No idea about big installations

P.S. previous comment with example specs: https://news.ycombinator.com/item?id=38266032

What a kind and helpful comment. Thank you!

You would still need a couple backups, standard plug in heaters and some kind of wood stove or furnace.

We just used a big cheap battery as a backup and the system is grid tied for horrible storms in winter and whatnot.

Everything was off the shelf — the new systems are crazy better than just a few years ago.

Reply on news.ycombinator.com