Mini split or gas heater??

[Nnorman1]

I’m wondering if a 36k mini split would work and be efficient in my 30x40 barn?

I’ve been told they’re great for a/c but not the best with heat when it gets to low temps.

I know a gas heater would work good if installed but rather use gas if I don’t have to.

 

[mike93lx]

What Temps are "low"? Where do you live? Adding a location in your profile helps a lot.

MN? Nope, not going to be enough. AZ? Probably more than enough

 

[Nnorman1]

I live in indiana so it’ll get to teens-single digits at times but mostly around 20-30 degrees in winter

 

[Nnorman1]

What Temps are "low"? Where do you live? Adding a location in your profile helps a lot.

MN? Nope, not going to be enough. AZ? Probably more than enough

My bad I should’ve put location.

 

[mike93lx]

All good. Welcome aboard.

Some mini's can heat that low (Mitsubishi). Insulation and desired temp will matter a lot.

If you want a/c anyway, you could start with a mini and see if it does what you need.

 

[Nnorman1]

All good. Welcome aboard.

Some mini's can heat that low (Mitsubishi). Insulation and desired temp will matter a lot.

If you want a/c anyway, you could start with a mini and see if it does what you need.

Wonder if a mini would run up the electric bill or if gas is a cheaper option in the long run as well?

 

[mike93lx]

Wonder if a mini would run up the electric bill or if gas is a cheaper option in the long run as well?

Heat pumps are very efficient, but electric rates vary greatly as well

A basic gas heater is about the cheapest way to heat overall, but if you are doing a/c anyway, you probably won't roi over has unless you are running resistive heat

 

[beemerphile]

No-one can answer whether a 36KBtu unit will do it without information about the construction and insulation. A Mitsubishi Hyper-Heat mini can take the cold temperature in stride. Local rates for natural gas and electric can change the equation regarding which is less expensive. Propane is almost never the cheapest solution.

 

[Nnorman1]

No-one can answer whether a 36KBtu unit will do it without information about the construction and insulation. A Mitsubishi Hyper-Heat mini can take the cold temperature in stride. Local rates for natural gas and electric can change the equation regarding which is less expensive. Propane is almost never the cheapest solution.

That’s All I have available near me is propane unfortunately, it’s been over 900 to fill my tank each time and I hate to go through it even faster heating the barn too lol

But what seer would be best you think? And a single unit or one with 2-3 head units be better?

 

[Jakemedic]

Be careful when you get your mini split, if you go that way. Mine is excellent for cooling, nice and efficient. It has a higher seer rating than my homes brand new central air. But for heating, not so much! The unit was a Mr. Cool DIY. I opted for a Mr. heater (no relation) and am quite happy with running natural gas (although maybe not this year) to heat my 24x32 shop. The price for both was less than a commercially installed brand that the heater was more efficient. Now that was 2 years ago as well. Your individual savings may vary.

I chose to pay particular attention to insulation and vapor barrier. That seemed to do the most towards savings. If you use a overhead gas heater, get a thermostat that goes down to 40 degrees. That also helps and the recovery times aren’t that bad.

best of luck with your project, I hope it meets and exceeds your needs.

Jake

 

[beemerphile]

The first money (fastest payback) to spend is to make sure that the insulation is where it should be. High SEER is cheaper than low SEER but equipment cost is higher. The SEER impact is highest with the worst insulation. So, again, insulation first.

To determine the best life cycle cost requires a lot of information about the structure, the fuel costs, and the cost and efficiency of the various options. Anybody who tells you what worked well for them is giving you useless information unless they live next door and the same guy built the two barns to the same spec. Multi-head vs, single head (or multiple single head) units depends on the air distribution needs. A couple of smaller single heads on opposite sides of the shop vs a multi-head unit gives you some system redundancy.

 

[Nnorman1]

Be careful when you get your mini split, if you go that way. Mine is excellent for cooling, nice and efficient. It has a higher seer rating than my homes brand new central air. But for heating, not so much! The unit was a Mr. Cool DIY. I opted for a Mr. heater (no relation) and am quite happy with running natural gas (although maybe not this year) to heat my 24x32 shop. The price for both was less than a commercially installed brand that the heater was more efficient. Now that was 2 years ago as well. Your individual savings may vary.

I chose to pay particular attention to insulation and vapor barrier. That seemed to do the most towards savings. If you use a overhead gas heater, get a thermostat that goes down to 40 degrees. That also helps and the recovery times aren’t that bad.

best of luck with your project, I hope it meets and exceeds your needs.

Jake

What did you keep yours set at in winter? And curious how much it raised your electric bill?

 

[theoldwizard1]

In both cases, you will have a problem evenly distributing the the heat !

A gas wall heater outs out a lot of heat quicker than a mini-split. This is good when coming into a shop that has had the heat turned down very low/off for sometime.

A gas heater is cheaper to install, but in the long run a mini-split is cheaper to operate.

Of course, a gas heater does NOT have an A/C mode !

 

[Nnorman1]

The first money (fastest payback) to spend is to make sure that the insulation is where it should be. High SEER is cheaper than low SEER but equipment cost is higher. The SEER impact is highest with the worst insulation. So, again, insulation first.

To determine the best life cycle cost requires a lot of information about the structure, the fuel costs, and the cost and efficiency of the various options. Anybody who tells you what worked well for them is giving you useless information unless they live next door and the same guy built the two barns to the same spec. Multi-head vs, single head (or multiple single head) units depends on the air distribution needs. A couple of smaller single heads on opposite sides of the shop vs a multi-head unit gives you some system redundancy.

I haven’t done insulation yet but it does have radiant barrier on the inside, but still plan on doing blow in insulation and metal on the interior

 

[WisJim]

The mini splits we installed in our house operate at rated efficiency down to 5 degrees and at over 73 per cent down to 15F below zero and still function well when it's colder than that. Since mini splits also do air conditioning, I recommend them.

 

[yeldogt]

It's all math ....

At 1200sf -- you have to think about how you will use the space. I have 1700 sf of space with only a 24k unit and it has no problem ..... it's well insulated. I also have a gas (propane) cabinet heater in that space as well -- so I have a choice in the winter

In many colder areas the heat load is greater then the cooling load and this makes for a miss match in sizing.

Tight well insulated space have no problem with single point heat and air .... they have to be tight.

As to working when cold out ..... you have to look at the specifications. All units will work down in cold temps .... the hyper heat units get you full output at those temps. Again -- it's math as far as how you go .... plug in yout electric rate and propane costs

 

[Iron Beaver]

As others have said, a heat pump will handle the temperatures just fine. That said, it will have to be one of a select few to do so. Mitsubishi's H2i Hyper-heat models and the Fujitsu Halcyon line come to mind

Like this: https://hvacdirect.com/mitsubishi-m...1-seer-ductless-mini-split-heat-pump8960.html

Or this: https://hvacdirect.com/fujitsu-15-000-btu-25-seer-ductless-mini-split-heat-pump-system-15lzas1.html

 

[Nnorman1]

As others have said, a heat pump will handle the temperatures just fine. That said, it will have to be one of a select few to do so. Mitsubishi's H2i Hyper-heat models and the Fujitsu Halcyon line come to mind

Like this: https://hvacdirect.com/mitsubishi-m...1-seer-ductless-mini-split-heat-pump8960.html

Or this: https://hvacdirect.com/fujitsu-15-000-btu-25-seer-ductless-mini-split-heat-pump-system-15lzas1.html

Would 12k btu be enough you think? Mr. Cool recommends 36k I think for 1500 sq ft

 

[mike93lx]

Would 12k btu be enough you think? Mr. Cool recommends 36k I think for 1500 sq ft

For $50, you can do your own load calc with hvac-calc.

That said, an uninsulated 1500 sq ft? Heck no

 

[dcg9381]

I’m wondering if a 36k mini split would work and be efficient in my 30x40 barn?

I know a gas heater would work good if installed but rather use gas if I don’t have to.

I cool 2400sqft with 48k of mini-split. You question depends on a number of factors (like insulation).
As others have mentioned the mini-splits that are designed for low temps will work. I'm in Texas, I have one not designed for cold temps.
Below 30 heating capacity rapidly drops off by 50%. We heat with propane supplement below 30 degrees in the shop. Temps that low only occur here a few days a year normally.

Local rates for natural gas and electric can change the equation regarding which is less expensive. Propane is almost never the cheapest solution.

When temps go below 30 here, our heat pumps basically get very "marginal". With ducted HVAC they'll eventually hit a temp offset and engage electrical resistance heat. Want to see money go away, try 2 x 60A electrical heaters running.

Last year I tested a "no power" scenario by using a ductless propane heater, 30K BTU. It was able to heat the whole house to 70 degrees no problem, about 3000 sqft (foam insulated home).

We just paid $3.10 per gallon for "bulk" propane... So propane costs can vary wildly unlike electrical. Natural gas would certainly be less, but isn't available.

 

[jack stand]

I haven’t done insulation yet but it does have radiant barrier on the inside, but still plan on doing blow in insulation and metal on the interior

Remember the better the insulation (including air sealing) is, the less the source of heating (or cooling) matters.
Read this one more time and
let it sink in and think about it.

 

[Jakemedic]

What did you keep yours set at in winter? And curious how much it raised your electric bill?

I use my natural gas heater. If I’m not in there, it is set to 40. Takes very little time to heat up the shop. Typically I go for 60. That way it feels good wearing a hoodie. The shops insulation would probably keep it above freezing on its own, but honestly never tried it. Might this winter though, natural gas prices are up 25% from last winter and it isn’t even cold yet. My mini split is rated to go down to 10 degrees but beyond trying it, I don’t think it would be very efficient.

 

[Jakemedic]

Remember the better the insulation (including air sealing) is, the less the source of heating (or cooling) matters.
Read this one more time and
let it sink in and think about it.

I definitely agree with Jack’s statement! I even put in an R19 garage door. Expensive? A bit, but why put a lesser level of door in when paying so much attention to insulation and vapor barrier? I also cut down on thermal breaks by using 8’ wide rolls of R19. No wood between the posts (except for the horizontal pieces to screw my plywood to). Taped all my vapor barrier joints with the special tape and sealed around every outlet (and I have a ton of outlets). My daddy always said, two ways to do things, the right way and again.

 

[u2slow]

I have to run the AC in the house to keep it as cool as the shop (no AC, open vented ceiling and soffits).

Unless the barn is very well sealed and insulated, I suspect high-btu fuel heat is the answer to heat it up quickly for while you're working.

 

[thammel]

I did both....have a reznor propane heater and a Mr Slim heat pump. My logic is that the heat pump will cool in the summer and provide efficient heat most of the year. When it needs a boost (hardly ever) the propane heater kicks in.

 

[mikeyr]

I have a hotdawg gas heater in my shop, had it for almost 20 years now. I even moved it from old shop to new shop. 2 years ago, I got a mini-split and since it can do heat and cool, I figured I would remove the hotdawg. Well last winter, I figure it cost me double in electricity keeping my shop warm over what the gas heater costs. Luckily, I was lazy and never got around to removing the hotdawg so this year, I will be using that again. And yes, I did the math with the cost of gas/elect from one year to the next, over here in Calif. electricity is more expensive than gas. Since I am in Calif. and I went stupid overboard on insulation, I don't use the heater much anyway, its set to keep the garage at 55 when i am not in there and when I am in there, I put on a sweater or kick it up a few degrees.

 

[jack stand]

Mike what's your electricity and gas/propane rates in CA for someone else's comparison?

 

[jjrbus]

Mini's are great unless you ever need a service call. A service call can wipe out years of energy savings. There was one recently posted $1400 in service calls then $2400 for new head. That was a Mitsubish. Warranty does not cover labor, labor warranty needs to be purchased separately.