Mini split equivalent for cold weather?

[bedn0009]

All,

Is there a mini split equivalent for the 1000 square ft shop I am building in Wisconsin? Caveat....I'm putting a second story above that may or may not be climate controlled in the future.

What about a regular residential NG furnace?

 

[James-W]

In my opinion, a mini-split works great until it gets really cold. Then you will want to have some supplemental heat.

I don't have a mini-split but I do have a natural gas Hot Dawg 60,000 BTU heater mounted on the ceiling and it works really well in my 24X36 garage. I also use a windows air-conditioner that I take out in the Fall when it starts getting cooler.

 

[Jagmandave]

I wouldn't think any heat pump is going to be an efficient source of heat in the cold you guys get up there....

If you have natural gas available it's the best way to heat the space, if you don't then I'd look really hard at solar heat. If you have NG, I'd also think a regular house style furnace/A/C would do the trick. In my shop out in the country we used a mobile home style furnace, which blew the heat out the bottom - which made a lot more sense to me than blowing heat up at the ceiling. We set it up about a foot off the slab on a simple frame and put vents on two sides....it heated a 20X50 shop on the coldest days.....

If you have good southern exposure there are what are known as heat panels - where you put a pane of glass in front of a box (which is simply the space between the studs) painted black and 6-8 ft tall, open 2 holes to the shop, one at the bottom and one at the top of that panel and you'll be surprised how much heat will come out of there. If you have room for three or four your shop will stay toasty warm...assuming you get the sunshine of course....

 

[bzinsky]

I wouldn't think any heat pump is going to be an efficient source of heat in the cold you guys get up there....

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They are still pretty efficient well below zero, the problem in Wisconsin is it may actually get so cold that the mini split is non-functional. It'd have to be like below -20, but that's the exact time when if you have anything that can't be frozen, like water lines, you don't want a heat pump as your sole form of heat.

 

[theoldwizard1]

They are still pretty efficient well below zero, the problem in Wisconsin is it may actually get so cold that the mini split is non-functional. It'd have to be like below -20, but that's the exact time when if you have anything that can't be frozen, like water lines, you don't want a heat pump as your sole form of heat.

ABSOLUTELY !

If it is in a garage, you might be able to just turn it off until the temp get back above 0F. If not, you will need some kind of auxiliary kind heat. LP is good back up. Either a wall furnace or a free standing unit, but you had better have a couple of 100 lb bottles because 2 or 3 nights at -20F will use up a lot of propane !

You also need a thermostat that will turn off the propane fired heat above 0F.

 

[Jackfre]

Rinnai EX38 direct vent wall furnace. It's what I'm putting in my new shop

 

[theoldwizard1]

Rinnai EX38 direct vent wall furnace. It's what I'm putting in my new shop

Perfect combined with a good low temp mini-split. It will handle the extremely low temp and can heat up a shop quickly if you set the thermostat back.

 

[bedn0009]

Perfect combined with a good low temp mini-split. It will handle the extremely low temp and can heat up a shop quickly if you set the thermostat back.

OK... but the cost to purchase and install both HAS to be prohibitive, right? Again.. the baseline is a NG Unit heater... which does the trick at around $1000 installed.

I'm happy to pay for a significantyl BETTER solution, but is a mini split the right choice ? Does the Rinnai cool, and if so, why the mini split at all?

Further... why NOT a standard forced air furance?

 

[bzinsky]

OK... but the cost to purchase and install both HAS to be prohibitive, right? Again.. the baseline is a NG Unit heater... which does the trick at around $1000 installed.

I'm happy to pay for a significantyl BETTER solution, but is a mini split the right choice ? Does the Rinnai cool, and if so, why the mini split at all?

Further... why NOT a standard forced air furance?

your answer depends on your use

What are you plans on when you're going to heat.

Do you want to maintain a certain temp 24/7? Or do you just want to heat to work in there?

Maintaining a temp and getting a garage up to temp quickly have two different solutions.

Maintain heat 24/7, in order of best to worst (cost to run is highest priority)
1. Radiant floor/gas
2. most types of gas heaters
3. Mini split heat pump (close to number 2)
4. propane (cost)
100. electric resistance heat

On demand heat to work in shop (btu's is highest priority)
1. Most types of gas heaters or kerosene hotdog
2. propane heater
3. Mini split heat pump
4. electric resistance heat
5. Wood burning stove
6. radiant floor

Cooling, on demand or maintain
1. Mini split
2. Traditional hvac
3. Window unit
4. portable AC (expensive to purchase for output, takes up a lot of space, and not very efficient)

 

[bedn0009]

When heating I'd like to keep the garage at 35-40 most days (25 of 30 days per month), and be able to turn it up 30 mins before working in there to get it to 50-60 or so to be comfortable.

It seems as though a basic unit heater is what I'm being led to... maybe there isn't a better option? This Rinnai furnace looks ****, but it's still only 82% efficient and is double the cost.

Still not much support for a traditional forced air furnace.

Anyone use a unit like they have in hotels... something that heats (gas) and cools via electric?

Does a radiant tube fit into this equation? Is it realistic with 9 feet high ceilings?

your answer depends on your use

What are you plans on when you're going to heat.

Do you want to maintain a certain temp 24/7? Or do you just want to heat to work in there?

Maintaining a temp and getting a garage up to temp quickly have two different solutions.

Maintain heat 24/7, in order of best to worst (cost to run is highest priority)
1. Radiant floor/gas
2. most types of gas heaters
3. Mini split heat pump (close to number 2)
4. propane (cost)
100. electric resistance heat

On demand heat to work in shop (btu's is highest priority)
1. Most types of gas heaters or kerosene hotdog
2. propane heater
3. Mini split heat pump
4. electric resistance heat
5. Wood burning stove
6. radiant floor

Cooling, on demand or maintain
1. Mini split
2. Traditional hvac
3. Window unit
4. portable AC (expensive to purchase for output, takes up a lot of space, and not very efficient)

 

[theoldwizard1]

When heating I'd like to keep the garage at 35-40 most days (25 of 30 days per month), and be able to turn it up 30 mins before working in there to get it to 50-60 or so to be comfortable.
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Anyone use a unit like they have in hotels... something that heats (gas) and cools via electric?

Those are call PTACs. Not a good choice,

Does a radiant tube fit into this equation? Is it realistic with 9 feet high ceilings?

Sure. Do you have natural gas ? If not, a high efficiency mini-split is still the most cost effective (operationally) the best solution except on the coldest days/nights.

 

[Jackfre]

Only 82%...Given that this is a product that many people will turn off and leave off for extended periods making it a condensing unit with water in the unit is just not a good idea. As well your only 82% misses the feature set of the product. It is modulating from 13000-38000btu in seven stages, modulating fan, cool to the touch, QUIET, programmable t-stat built in, vent included and in 50 years in the business, the most reliable and durable heating appliance I've ever seen. The EX38 is replacing the ES38 as I write this. The ES did not have the programmable stat. It will take you two hrs to set and trim this unit, if the gas line is local. I think you will be surprised how well it heats and how little gas it consumes.

I must acknowledge my bias here, again, as it pertains to the Rinnai. I was their rep in New England for 20 years and still consult with them. That said, I would not be without them in my home and the new EX38 will be in my new shop this season.

 

[justinjoyal]

To be honest I am not aware of the kind of temperatures you get in Wisconsin, but there are mini-splits effective up to -22 F.

If you're not seeing temps below 0 F and the building is well insulated, a right sized mini-split could do the trick.

However I would advise on having a second source of heat just in case, something that would help bring the temps up quickly when needed and serve as backup if the mini-split(s) fail.

 

[bzinsky]

When heating I'd like to keep the garage at 35-40 most days (25 of 30 days per month), and be able to turn it up 30 mins before working in there to get it to 50-60 or so to be comfortable.

It seems as though a basic unit heater is what I'm being led to... maybe there isn't a better option? This Rinnai furnace looks ****, but it's still only 82% efficient and is double the cost.

Still not much support for a traditional forced air furnace.

Anyone use a unit like they have in hotels... something that heats (gas) and cools via electric?

Does a radiant tube fit into this equation? Is it realistic with 9 feet high ceilings?

I don't think you should worry about the 82% efficiency. Keeping a space at 35-40 degrees requires just a fraction of the heat it takes to keep a house warm at 70 degrees.

The heat required is directly related to the difference in temperature between the outside and the inside.

If it's 20 degrees out, you're garage is already likely 25 degrees just from geothermal heat. So you'd only need enough heat for a 10-15 degree temperature rise. A house, under the same guidelines, would need to maintain a 45 degree temperature rise. Huge difference in energy.

I have a gas forced hot air in my garage, while I don't bother maintaining temp, I do turn it on 20-30 mins before I get it. What I would highly suggest is a wifi thermostat. I plan to do that for mine. Instead of waking up/shower/coffee/dressed, then walking to your garage and turning it on, you can turn it on the minute you wake up so it's nice and warm when you're ready to work. If you're garage is not in wifi range, then just run a wire from the garage to the house and install a light timer so you can just bypass the thermostat and turn it on for 30 minutes.