First major accomplishment of home shop build

[Crazyraceguy]

I have been slowly messing around with turning the garage into a woodworking shop. By slowly, I mean about 80% of the walls are furred out and insulated, ceiling is next.
The big thing is the mini-split, 12k BTU Mitsubishi, installed today. It was a fairly nice day for working outside. It rained like crazy yesterday and was in the upper 90s every day last week, never over 83 today.
It took them about 4 hours, with training a helper. I was very impressed with how quiet that thing was.
Even with my incomplete insulation, it seems to take the heat away very quickly.
Things might move along a little faster now that it will be bearable out there.

 

[SoonerFan]

[member=58857]Crazyraceguy[/member] you will love the mini split.  I have had one in my shop for 3 1/2 years now.  It’s a great solution for a shop.  Since I use my shop almost everyday I basically set it and forgot it.  My HVAC contractor said it is easier on the unit and more efficient to just run it.

In the winter I set it to 61F.  In the summer when it is hot and humid I set it at 77 at night and 74 during the day when I am in there.  Leaving it on in the summer helps control the humidity which I appreciate. 

Happy to hear you are making progress at the home shop. 

 

[rvieceli]

Looks great CRG. I’m sure you will love that thing.

Ron

 

[Cheese]

This will be an interesting thread.  [popcorn]

For my garage I've gone all in with in-floor heating but for summer use I'm thinking about adding a mini split. The lower garage area is always about 20º cooler or hotter than the outside temp. Today the outside temp was 85º while the garage was 70º. The upstairs loft however was 101º. Open the skylights and it cools down to 93º after about 20 minutes. So ya this mini split thing is very interesting.
The temperature profiles of Ohio and Minnesota aren't that far off.

 

[rvieceli]

[member=44099]Cheese[/member] you might want to think about doing two mini splits and zone your space. One for the attic and one for the main floor.

They are a fairly easy DIY physical install if you are handy and can bend copper tubing without kinking it. For purging/charging you’ll need the proper equipment or a friend in the HVAC arena.

My friends that have them really like them a lot. Do a great job of cooling and pulling the humidity out of your space.

Ron

 

[Crazyraceguy]

So far it has been great. It dropped the temp and humidity really quickly. It was pretty hot and sunny while they were working. I had both doors open for the slight breeze it can produce.
Just like any other HVAC job though, as soon as it starts getting cool (or warm in winter) they have to leave, for the next one.
Today just turned around again, quite a storm is brewing, it's 82 and dropping, almost dusk looking at 1pm.

I guess the real thing is, how much it will cost to run.

 

[BarneyD]

I never had A/C in my stand-alone two car garage workshop. I've just had a gas heater for winter. If it was really hot in the summer, I simply went in the house. All that changed when Covid hit and I was working from home (in my shop). I purchased and installed a mini-split for sanity's sake. And it's been wonderful. I couldn't imagine being without one now. Super quiet and very efficient (inverter driven on a 15A circuit breaker). And I noticed no change in my electric bill after installation. I think you'll love one, [member=44099]Cheese[/member].

 

[squall_line]

[member=44099]Cheese[/member] you might want to think about doing two mini splits and zone your space. One for the attic and one for the main floor.

They are a fairly easy DIY physical install if you are handy and can bend copper tubing without kinking it. For purging/charging you’ll need the proper equipment or a friend in the HVAC arena.

My friends that have them really like them a lot. Do a great job of cooling and pulling the humidity out of your space.

Ron

[member=44099]Cheese[/member]  You also may want to consider if/how the space is divided between floors, as it may end up nigh impossible to heat the lower part in the winter or keep the upper part cool in the summer without the other being wholly unpleasant.

 

[Crazyraceguy]

I never had A/C in my stand-alone two car garage workshop. I've just had a gas heater for winter. If it was really hot in the summer, I simply went in the house. All that changed when Covid hit and I was working from home (in my shop). I purchased and installed a mini-split for sanity's sake. And it's been wonderful. I couldn't imagine being without one now. Super quiet and very efficient (inverter driven on a 15A circuit breaker). And I noticed no change in my electric bill after installation. I think you'll love one, [member=44099]Cheese[/member].

Yeah, I was surprised by the quietness. With the fan on low, you can't even tell it's running, unless you walk in front of it. It makes sense though, the working part is outside.
This one isn't large, by any means, but it is 12000 BTU, 240v on a 30amp breaker. Of course that is max, and it wouldn't be running like that all the time. It's supposed to be very efficient, but it has to cost something extra?

 

[FestitaMakool]

Mitsubishi units are great, maybe one of the best.
I have two warming my house, almost never ran for cooling.

I’m not familiar with the specs on the units sold in the US but here’s what I know:

One unit, two floors - connected with open air circulation:
Mount it downstairs for heating and upstairs for cooling (Determine use/need first)

For heating, mount lower, down to the floor.
For cooling mount high towards ceiling.
(Some if not all companies here follow the instruction manual - which recommends mounting high under ceiling - because, as default these are “air coolers” - I’ve argued and requested low mounting.. Too many don’t know that cold air sinks, warm air rises.. Including installers and retailers)

The units draws a lot more power in cooling mode than warming mode (Units for Europe - yours may differ)
Look for COP or SCOP values (Heat efficiency) - How much heat it delivers vs amp/power draw.

EDIT: As an example, my Mitsubishi at its best (outside temperature of +8°C) has a power draw of 800 Watts - but deliver heat between 4,5-4,9 times that in released heat (3600-3900 Watts)
COP = 4,9

 

[tsmi243]

(Some if not all companies here follow the instruction manual - which recommends mounting high under ceiling - because, as default these are “air coolers” - I’ve argued and requested low mounting.. Too many don’t know that cold air sinks, warm air rises.. Including installers and retailers)

If the heating is done via refrigerant (called a "heat pump" in the US)- then the height is probably more about preventing oil from getting trapped in the indoor section.  I'd stick to the instructions.

 

[mino]

(Some if not all companies here follow the instruction manual - which recommends mounting high under ceiling - because, as default these are “air coolers” - I’ve argued and requested low mounting.. Too many don’t know that cold air sinks, warm air rises.. Including installers and retailers)

If the heating is done via refrigerant (called a "heat pump" in the US)- then the height is probably more about preventing oil from getting trapped in the indoor section.  I'd stick to the instructions.

Stick to the instructions can both be what FM says and not.

Recommended placement for a *cooling* indoors unit is indeed below the ceiling. But I have never seen instructions where a non-ducted indoors unit meant *for heating* was advised to be placed below the ceiling. That would completely defeat its purpose. And casual people know this here, not just "plumbers". (CZ, not UK/US though, so so YMMV)

That said, I can imagine there may be a market in the US for "basics" units that can only be used for cooling and only with the heat exchanger placed lower than the indoors unit. Places like the Cali are a big market after all and having the heating as only an emergency addon may be fine there.

 

[squall_line]

Without derailing the thread too much, one of the big, long, difficult slogs for the HVAC industry in the US has been to drag them kicking and screaming into the realm of two-way condensors/heat pumps and true Schedule J (load) calculations to properly size units.  It's easier to oversize a unit and put in a traditional air conditioner and furnace combination.  FUD (fear, uncertainty, and doubt) about backup heat for 1% edge cases paralyzes a lot of people, too.

 

[Ebuwan]

Congrats!

We had an addition on the house (1st floor and basement space), and had an HVAC contractor do two zone, and the upstairs is a ducted blower in the attic space, and the basement is a head unit on the wall like you have. Works fantastic. That unit is a Mitsubishi.

A few years ago I did a Mr. Cool DIY in the garage/workshop. Absolute game changer. I got the 24k unit, cost about $1800 from Costco. Took me a few hours to install, and put in a condensation pump (it's not on an outside wall). Prefilled lines, was super easy, just requires putting the extra ling behind something.

My HVAC guy said those DIY's are great cost wise. The catch will be if it needs a repair; The Mr. Cool will basically be a Replacement project, but the Mitsubishi he will be able to get parts forever. The other advantage with the Mitsubishi it will more likely perform much better when it gets really cold out (for heat). I'd hope so, for the price difference. The price difference is quite considerable.

But the Mr. Cool, if it gives me a few more years i'll be happy, and a replacement of it isn't a huge project, as nothing is buried in walls.

 

[smorgasbord]

the Mitsubishi he will be able to get parts forever.

Well, I have an old Fujitsu mini-split, about 12 years old I guess, and couldn't get a replacement louver motor from anywhere. One installer tried contacting Fujitsu and said the parts are no longer available.

Now, maybe that's just Fujitsu, but this was a professional installation from a well-respected company in the AC business. So, I do doubt "forever" - might be just 5-10 years.