Mini split vs Q-mark heater

[Joe69]

After my post about garage heat, I have more questions. Please bear with me, I'm just trying to make the best decision for my needs.

Several people suggested I get a mini-split, which I had never heard of until then. After doing some reading, I've concluded it's basically a hotel room style system. It has some interesting benefits, but the searches I've done have muddied the water some.

First off, is this basically a heat pump system? It sounds like it is. I've heated my previous and current homes with heat pumps, so I understand how they work.

Secondly, if they are a heat pump, then I assume they have electric backup heat?

My old garage was heated with a Qmark 230v hanging electric heater. It was extremely reliable, but I can't really tell you how efficient it was.

I don't have any intentions of cooling my garage in the summer, I'm more interested in heating it. Would another Qmark be a better choice for me? It's a self contained electric heater. It would basically only require some wiring, and hanging the unit.

My main objective here is to prepare myself for retirement. I'd rather spend a little more up front, and be more efficient for the future. I'm trying to keep my post retirement bills as low as possible, fixed income and all.

I'm about 9 years from retiring, but time goes by fast. The closer I get, the more I think about things differently.

Thanks for your time.
Joe

 

[Will S.]

If you have no desire for cooling, then just get the electric furnace for a fraction of the cost of a mini-split.

P.S.
A retired friend who lives nearby, built his dream garage about 3 years ago, complete with 2 post lift, commercial grade compressor, etc. He installed an electric heater similar to what you described, for his 1600 sf attached garage, and it does a very nice job.

 

[aunsafe2015]

My main objective here is to prepare myself for retirement. I'd rather spend a little more up front, and be more efficient for the future. I'm trying to keep my post retirement bills as low as possible, fixed income and all.

The mini split will be significantly more efficient. Many units have COP greater than 2.5 well below freezing. In other words, pure electric resistance heat will cost nearly 3x more per BTU.

That said, if you have no intention of cooling, the mini split may be so much more expensive than an electric furnace that it may not make economic sense.

Btw yes mini splits are heat pumps. But no, most do not have back up electric heat strips. Many mini splits provide full heat capacity down to sub zero temperatures, so backup electric resistance heat is not needed.

 

[Joe69]

I did the calculator, and it comes up around 12k. The 12k unit is only $800-$900 for a mini-split.

Joe

 

[dcg9381]

Factor in the installation hassle - a lot more electrical, two coolant lines, and a drain. As a "heater only" - I'd definitely NOT go this way.

These appear to me (at least the units I've ordered) to be heat pump units. Looking at the specs, as temperatures approach freezing and below, these units really drop in heating efficiency (by a factor of about 50%) - so take that into consideration. I haven't seen units with aux heat strips - and doing so would really up the input power requirements. A 12k unit is probably less than 10A cooling only...

 

[Will S.]

Another factor to consider with mini-splits, is that unless you plan to keep the garage at 62* or more, keep in mind that most will no allow a lower set temp in heat mode. They also require a fairly lengthy time to warm a cold shop, depending on the starting temp. Perhaps an entire day.

I installed a 12k mini in a media room ham shack back in August. It does a nice job in cooling. But as I mentioned, in heat mode it's either going to be off, or set to maintain 62 or more. Also remember that the blower does not cycle off when set temp is reached. It runs 24/7, and yes, that is not a system fault. That is the way it works, so check on that before you decide.

 

[justinjoyal]

Mini-splits do NOT have aux. heat. Don’t confuse the defrost heater with aux.

If looking for heat only, a simple electric heater will do.

Also dont confuse a mini-split with a hotel style PTAC.

 

[dfiler2]

When it comes to efficiency of the electric heater, they are all the same, 100%. If you don't need or want cooling, then the electric is the best choice for you.

 

[Citation]

Some mini splits have an 'away' heat setting that can hold temps in the 40s to 50s. The one I installed had a dehumidify mode as well. The OP's original concern was humidity control on cool days. A mini split would actually do that job quite well. The fall off in heat performance occurs when it's too cold to worry about humidity. The AC can also help with humidity in the summer.

That said, basic electric heat will be cheaper/easier to install and work even on very cold days.

 

[finn]

When it comes to efficiency of the electric heater, they are all the same, 100%. If you don't need or want cooling, then the electric is the best choice for you.

You should correct your post to say “when it comes to an electric RESISTANCE heater, they are all the same”.

A heat pump with a COP of 2.5 is two and a half times as efficient as an electric resistance heater.

It’s all about how the mathematics in the thermodynamic cycle works in the heat pump.

Don’t forget that the heat pump will also dehumidify in the summer months.

 

[Toomanytools?]

Joe, What size garage? Some of your knowledge on Mini splits is off, if you don't need to cool the space then a MS might not be the right choice. One of your posts I think said you have natural gas how about a blue flame wall heater? I know several people use them and love them.

 

[MrSurly]

Not to address the O.P.s question, this doesn't apply to his situation, just a tangential subject:

When it comes to efficiency of the electric heater, they are all the same, 100%. If you don't need or want cooling, then the electric is the best choice for you.

I really wish people would not repeat this old saw without 'completing the statement'. Folks who are looking for info will swoon to see "100% efficient" but even though it can be true in context, the claim is incredibly misleading.
Electric strip "resistance heating" is actually the *WORST* way to heat dollar-wise. How can the COSTLIEST method also claim "100% efficiency"?
The claim is true ONLY in regards to the lack of a flue. Yes, with electric strip heat ALL the energy you are paying for IS delivered inside the building, as opposed to a gas system where some portion of the energy is lost as heat in the flue pipe. This means electric is a more efficient utilization of the delivered energy; if all other factors were equal, it would be all that mattered. Things are not at all equal, of course, as the COST of the energy is dramatically HIGHER for electric versus gas.
Modern furnaces have AFUE ratings of about 78% up to 97%(!), so IOW, you're losing likely 15~20% of the delivered energy as heat in the flue... but the cost of electricity (by BTU) is so much higher than gas, you only have to look at the numbers to see that despite the better 'utilization', The cost to heat with electric strip heat is tremendously higher than to do the same job with gas. The better *money* utilization is gas, by far. (The exact numbers differ depending on your local rates and the efficiency ratings of the equipment you are comparing. Online calculators abound.)

My point is not to be pedantic; the "100% efficient" claim NEEDS to be qualified.

* Note that a heat pump (all mini-splits with heat are heat pumps AFAIK) is a type of electric heating but it is mechanical, not resistance, is not 100% efficient, costs less to operate than strip heat but still costs more than gas.

 

[dcg9381]

Note that a heat pump (all mini-splits with heat are heat pumps AFAIK) is a type of electric heating but it is mechanical, not resistance, is not 100% efficient, costs less to operate than strip heat but still costs more than gas.

Living in the south (where we rarely use head) and being subject to a few days every few years where a heat pump cannot keep up - I can tell you that a heat pump that cannot bring the structure up to a livable temperature (running it all the time) is throwing money away. It hasn't happened very often, but when it does - running that compressor at 100% of the time when it won't heat the structure is a waste of money (I agree that there is some argument that it IS producing some heat). This is why many traditional systems have aux heat strips. Heck, even some modern RVs using heat pumps have aux strips installed as an option.


That being said, these split systems DO produce more heat at lower temperatures than other systems, but unless the heat pump can "keep up" - you're looking at using some aux heating somewhere. Just don't want you to have to do "both" systems when one might do...

 

[Joe69]

Joe, What size garage? Some of your knowledge on Mini splits is off, if you don't need to cool the space then a MS might not be the right choice. One of your posts I think said you have natural gas how about a blue flame wall heater? I know several people use them and love them.

My garage is roughly 24'x22'. I do not have access to natural gas, or I would go that way.

If I get a mini split (heat pump with no heat strips), wouldn't it just run all of the time when it gets very cold? That doesn't sound cost effective to me. The mini split was sounding like a good idea, until this came up. I had a heat strip go bad in my heat pump system in my old house once. The furnace just ran and ran, and was just barely keeping the house near temp.

I'm starting to lean towards another Qmark heater. The last one was extremely reliable, and I believe my garage is insulated well enough that it won't run excessively. That, and I could set it to 45-50 degrees and leave it. My moisture problem occurs when the floor is bitter cold, and we have a sudden 65 degree day.

I agree with whoever brought up the 100% efficiency thing. Yes, electric heat is 100% efficient, but is it the most cost effective way of heating?

Joe

 

[Toomanytools?]

Some models do have a low set point of 50F, Fujitsu's cold climate mini-splits have a "Minimum Heat" mode, which keeps it about 50F. The lowest setting in normal heating mode is 60F. Also Mitsubishi has a set point of 50. With heating ranges from 5-65 degrees outdoor temp. Your space being under 600 square feet should be easy to heat if insulated well. I would think the cost to run a mini-split will be cheaper than the Qmark, but the Q will cost you about $400-500 up front and a MS may run up to $2000.

I'm looking at a Mini-split for my workshop which is about 1000 sqft, installed single unit Daikin is around $2500. I want to keep the winter temps about 50 when not in use (mild winters) but really want AC as our summers can be 110 degrees for weeks.

I think in your case the Qmark might be the ticket and if it doesn't work out in a year or two you could sell it and do something else.

 

[dtaski]

I'm the OP of this thread.
https://www.garagejournal.com/forum/showthread.php?t=403924&showall=1

I live in South Central PA and my mini split has been running great. It's been kinda mild and my electric bill has increased about $30 / month over previous years.

I was skeptical about a MS system but it's proven me wrong. I made the right choice for my needs !

 

[justinjoyal]

Not to address the O.P.s question, this doesn't apply to his situation, just a tangential subject:


I really wish people would not repeat this old saw without 'completing the statement'. Folks who are looking for info will swoon to see "100% efficient" but even though it can be true in context, the claim is incredibly misleading.
Electric strip "resistance heating" is actually the *WORST* way to heat dollar-wise. How can the COSTLIEST method also claim "100% efficiency"?
The claim is true ONLY in regards to the lack of a flue. Yes, with electric strip heat ALL the energy you are paying for IS delivered inside the building, as opposed to a gas system where some portion of the energy is lost as heat in the flue pipe. This means electric is a more efficient utilization of the delivered energy; if all other factors were equal, it would be all that mattered. Things are not at all equal, of course, as the COST of the energy is dramatically HIGHER for electric versus gas.
Modern furnaces have AFUE ratings of about 78% up to 97%(!), so IOW, you're losing likely 15~20% of the delivered energy as heat in the flue... but the cost of electricity (by BTU) is so much higher than gas, you only have to look at the numbers to see that despite the better 'utilization', The cost to heat with electric strip heat is tremendously higher than to do the same job with gas. The better *money* utilization is gas, by far. (The exact numbers differ depending on your local rates and the efficiency ratings of the equipment you are comparing. Online calculators abound.)

My point is not to be pedantic; the "100% efficient" claim NEEDS to be qualified.

* Note that a heat pump (all mini-splits with heat are heat pumps AFAIK) is a type of electric heating but it is mechanical, not resistance, is not 100% efficient, costs less to operate than strip heat but still costs more than gas.

We are talking about efficiency in terms of input VS output, not related to cost of operation.

A heat pump consumes less electricity to produce more heat, it’s simple maths.

Costs of operation depend on utility rates. Your statements don’t apply everywhere.

 

[Citation]

Joe,
What I recall of my Pioneer system was it would turn off when it decided it was too cold outside or icing over was a risk. I think the icing over part was the bigger concern. Disclaimer, I didn't pay much attention to the heating aspects of the system. My objective was first to be able to claim I had working AC on the second floor when I sold the house, and second, to keep the summer temperatures in the attic more reasonable since I used the space for a lot of storage. Before fixing the AC my attic room would get upwards of 115 F in the summer. I could still heat the attic using the gas furnace that was part of the previous forced air HVAC system.

BTW, unlike many forced air HVAC systems, the mini-splits typically have multiple power settings and fan speeds. Especially when using the AC, the system tries to run slower and for a longer period of time vs faster at a higher cooling rate. Don't be surprised if the system seems to run a lot when heating/cooling loads are low. That's by design.

 

[dfiler2]

* Note that a heat pump (all mini-splits with heat are heat pumps AFAIK) is a type of electric heating but it is mechanical, not resistance, is not 100% efficient, costs less to operate than strip heat but still costs more than gas.

This is extremely misleading and might be true in some areas but certainly not everywhere.

 

[foodie]

Joe, just my opinion on a Qmark and as a point of reference for you. I could not do a mini split because I live in a condo. I could not do a gas fired unit. I just installed the Q-Mark MUH 35 with the electrical cord that I paid extra for. I did not want to hard wire it. My garage is pretty well insulated it is 12x22 with very high ceilings. I had an electrician do all of the wiring for a 220/240v line. I turned it on with a 32 degree day outside after it was installed and my garage came up to 62 degrees within 15 minutes or so. I am very happy with this unit, it gets good reviews. One of the other GJ members recommended it to me.

 

[dcg9381]

I just installed the Q-Mark MUH 35 with the electrical cord that I paid extra for.

I looked this up, it's 5000 watts, about $400. It runs off a 240V circuit drawing 21A max. So any standard dryer outlet would work.

For reference, the Daikin 24K BTU mini split that I ordered costs $1400. At full output, it pulls about ~14A at 220V and can put out about 9000 watts of heat. So it's about 3x as expensive as the Q-mark, but is more than twice as energy efficient if the temperature is above freezing when considering heating.

Installation estimates on the mini-split (professional) come in at $1000-$2000 additional (ridiculous, but even DIY it's a lot more time and trouble). Lot more parts and electronics to fail.


As the temperature falls, however, that heat output from the mini-split is reduced to around 5000 watts... Don't get one if you're in "really cold" climates (I was just in -9 in Colorado).

 

[Joe69]

My garage at my previous house had a Qmark similar to an MUH072. It was roughly 900 sq ft with 8' ceilings. It did an excellent job for the 14 years I lived there. It was there when I moved in, and was still working perfectly when I moved out. I have no idea how much it cost me to run, because it was on the same meter as the house. I do know the only thing I ever did to it was clean it.

Joe

 

[PoorOwner]

I don't know if you spend on a $500 heater.

Have you seen the Dayton? They work great for a 2 car garage, you can get one of the copies for less, but if you can try to ****** this one with a 20% off coupon. The Dayton version keep their values much better.

https://www.zoro.com/dayton-electri...VAdtkCh1UewfCEAQYASABEgKOp_D_BwE&gclsrc=aw.ds

 

[foodie]

^^ That is a great price. I guess it depends on what website you get it from. They even have one that looks like my Qmark branded as a Dayton, that is cheaper than what I paid for mine. Shop around if you decide to go that route.

 

[MrSurly]

* Note that a heat pump (all mini-splits with heat are heat pumps AFAIK) is a type of electric heating but it is mechanical, not resistance, is not 100% efficient, costs less to operate than strip heat but still costs more than gas.

This is extremely misleading and might be true in some areas but certainly not everywhere.

Please do enlighten me. Is there ANYwhere that natural gas service is available....that the effective 'cost per therm' is HIGHER than electric heating or heat pump?
I can't think of where that market exists but i'd like to learn.
I don't believe my statement was "extremely misleading" but show me(?)

 

[MattT]

Please do enlighten me. Is there ANYwhere that natural gas service is available....that the effective 'cost per therm' is HIGHER than electric heating or heat pump?
I can't think of where that market exists but i'd like to learn.
I don't believe my statement was "extremely misleading" but show me(?)

My heating costs this winter look like they'll end up around $200 in electricity, @ $0.094/kWh, for mini split heat pumps and less than 50 gallons of propane supplemental heat. I'll call it $300 to be safe though it'll probably be closer to $250.

A quick googling found fixed costs for natural gas of over $200 a year in Dallas and "about a dollar a therm" for the actual gas which would be another couple hundred for gas used. Based on that it'd likely cost me at least an extra hundred dollars a year to heat with natural gas.

 

[aunsafe2015]

my heating costs this winter look like they'll end up around $200 in electricity, @ $0.94/kwh, for mini split heat pumps and less than 50 gallons of propane supplemental heat. I'll call it $300 to be safe though it'll probably be closer to $250.



A quick googling found fixed costs for natural gas of over $200 a year in dallas and "about a dollar a therm" for the actual gas which would be another couple hundred for gas used. Based on that it'd likely cost me at least an extra hundred dollars a year to heat with natural gas.

$0.094

 

[MattT]

$0.094

Yeah

 

[theoldwizard1]

Several people suggested I get a mini-split, which I had never heard of until then. After doing some reading, I've concluded it's basically a hotel room style system. It has some interesting benefits, but the searches I've done have muddied the water some.

That is called a PTAC. Very common in many apartments. They are notoriously INefficient. They don't need to be because the renter pays the electricity. Their big claim to fame is easy of swapping a bad one out and a good one in. Apartment complex always have a several on hand.Any "handy man" can perform the swap. When the supply of good ones gets low, they call the HVAC guy who picks up all of the bad ones and repairs the,

Secondly, if they are a heat pump, then I assume they have electric backup heat?

Some do. The best one do NOT ! This is very much a case of BUYER BEWARE !

My old garage was heated with a Qmark 230v hanging electric heater. It was extremely reliable, but I can't really tell you how efficient it was.

As stated electric resistance heat is 100% efficient, but the cost of electricity in most part of North America is very expensive. Resistance heater are not too expensive and are easy to install. If you only plan on running it 10-20 hours a month, it maybe a good solution.

My main objective here is to prepare myself for retirement. I'd rather spend a little more up front, and be more efficient for the future. I'm trying to keep my post retirement bills as low as possible, fixed income and all.
.
.
.
I'm starting to lean towards another Qmark heater. The last one was extremely reliable, and I believe my garage is insulated well enough that it won't run excessively. That, and I could set it to 45-50 degrees and leave it. My moisture problem occurs when the floor is bitter cold, and we have a sudden 65 degree day.

So you main objective is humidity/moisture control.

Any heat source will run whenever the thermostat calls for it.

When heating with a heat pump, they use the LEAST amount of electricity per BTU generated when the outside temperature is between 30° and 70° (+/- 10°). Electric resistance heat always consume 1,000W to generate 3,412 BTU of heat because the energy is being coverted directly from electricity to heat. A heat pump merely "moves" heat form one place to another.

 

[Toomanytools?]

When heating with a heat pump, they use the LEAST amount of electricity per BTU generated when the outside temperature is between 30° and 70° (+/- 10°). Electric resistance heat always consume 1,000W to generate 3,412 BTU of heat because the energy is being coverted directly from electricity to heat. A heat pump merely "moves" heat form one place to another.

This is some of the best info I've seen posted for awhile.