Looking at Nat gas heaters

[66HertzClone]

When I had natural gas run to my house to replace the oil I was using before I had the guys put a connection in my garage so I could add a heater out there when I was ready. Well, I'm ready, the garage is about 600 sq. feet, I don't know the ceiling height but it appears to be a normal garage height.

Northern Tool is running a special on heaters and it looks like this one will fit my needs pretty well.

I tried to link to the page on the NT website but it's not working. It is the Mr. Heater Big Maxx 80K BTU unit, model MHU80G, the price looks pretty good and there is a gift card offer that is going on at the same time. With a purchase of the flue kit and thermostat I would get a $100 gift card. Is this overkill for my space?

 

[Chevy-SS]

I put a very similar heater ('Hot Dawg' by Modine) in my garage that I built about 5 years ago. I went to local Plumber's Supply (where I bought all the parts) and worked with the tech guy. He is a genius with the calculations and all that. You want someone that can take the appropriate info from you and then crunch the numbers to give you the correct unit and other installation guidance.

That's my $.02 anyway. Good luck with it. Mine works awesome!

 

[JeepJohn62]

I put one in my garage many years ago (2003) for a 1200sf space. I used the 75k unit and it works well. I'm in Alaska and my garage space is well insulated.

There is probably a guideline for a 600sf space and climate.

I think they have updated the control board. I have replaced the fan relays several times.

John

Sent from my SM-A102U using The Garage Journal mobile app

 

[HoosierBuddy]

If your garage is insulated, I would guess 80,000 BTU would be more than you need and you might run into short cycling of the heater. Not saying it wouldn't work...just doubt it would be ideal....but using an online calculator to determine your heat loss would be a great place to start.

Phil

 

[iced98lx]

Whenever a "which heater" "how big" type question comes up you're going to get two kinds of answers here.

#1 - "Do the heat loss calculation, talk to someone who can/does them, and size correctly for the space you have." This idea centers around the fact that short cycling (running a heater for small short bursts where it doesn't have time to evaporate condensate) is undesirable and efficiency usually involves minimum run times. You will want to understand recovery rate when you open a garage door and factor in how often that happens and how fast you want it to recover. Same for when you go to work in the garage and turn the thermostat up.

#2 - "Bigger is better" - This centers around "I don't want to ever not have enough heater" and is typical of a home center sales situation or DIY that hasn't dove down the rabbit hole. Pick one size bigger than the product documentation suggests because bob down the street has an uncle with the same size garage as you and he can't get it over 50 degrees with it running full blast with the one you're looking at, better safe than sorry.


IMHO, most of the problems that #2 suggests you're going to run into with #1 are easily avoided by understanding your heat loss as accurately as possible. A slapdash heatloss calculation may suggest a smaller unit than you need but after taking the time to get all the details right suggest a slightly bigger/better fitting one.

Sooo.

Your question is "is 80,000 BTU overkill for 600 SQ FT"

In most situations, yes, it might be as much as twice as much as you need.

Really though, a lot of it depends on how your space is built and how you use it. If you have a great tightly built/insulated garage with good doors that don't open frequently, yes, you're probably buying way more than you want/need.

If you have an uninsulated space that has uninsulated doors that is drafty and you're opening doors every 45 minutes because you're running cars in and out for repair then you might be happy with an 80k btu unit that runs all day and then doesn't run much at night due to set back.

Sorry for the long post but just trying to be up front about how most are going to approach here.

 

[66HertzClone]

I should have spent more time looking, I went back and found a smaller unit, this one if 50K BTU, probably much better matched to my space. I will take the advise given and get some assistance in calculating what I do need.

My garage doors are well sealed and are insulated, I have two windows in the garage and they are very nice Pella windows, no man door. I'll have to go up into the attic to see what if any insulation is present.

 

[iced98lx]

I should have spent more time looking, I went back and found a smaller unit, this one if 50K BTU, probably much better matched to my space. I will take the advise given and get some assistance in calculating what I do need.

My garage doors are well sealed and are insulated, I have two windows in the garage and they are very nice Pella windows, no man door. I'll have to go up into the attic to see what if any insulation is present.

Off hand I'd agree that 50k is matched to your space based on your description but attic insulation, wall insulation, which way your overhead doors point are all likely to influence your choice. Most heat loss calculators are geared towards houses and don't handle the air-leak nightmares that are overhead doors and I suspect that's where the oversizing you see a lot really came from.

Are you planning to keep the space at a certain temp? Run it up to a higher temp regularly?

It's one thing if "I just want the garage at 45 degrees all the time" is your goal, another if "I want it at 45 until I turn the heat on at 7AM saturday then it better be 65 by 8 AM when I'm done with my coffee" is the goal

 

[Kunze]

I was looking at the same line of heaters, although from Menards. I ended up going with the 50k unit. My garage is similar to yours in size and windows, although my windows are currently old single pane glass (this needs to be replaced). I just did my walls with R-19 and will be blowing R-39 depth into the attic this weekend. I do not have real life tests yet as this will be my first cold season since installing it all. However, my calculations for my Wisconsin winters and configuration led to the smaller unit.

 

[66HertzClone]

My intention would be to use this on an as needed basis, if I have a project going on the will have me in the garage for a few hours or the day, I'd light it off in the morning before my coffee. I see no need to keep it going all the time to maintain a certain temp. I get some rebates from one of my vendors, these Visa gift cards come in handy when deciding on spending money on something like this.

I've been looking at turntables, I have a decent vinyl collection and sold the turntable I had when I got married. Back to being single I have made a space in my house to enjoy listening to some nice music. Another one of these cards being used for this purchase.

 

[Jim greengo]

I was going to ask you what was the next size down from the 80,000,but it looks like you already found it.

 

[yeldogt]

With the cost of natural gas ...my guess is you will maintain a temp. With any amount of "stuff' in the space having it at a reasonable temp is nice and makes for quick and comfortable working. It can take forever to warm up a tool box

My well insulated 1600sf studio only has 40k and it costs me a few hundred bucks in the winter ---

 

[HoosierBuddy]

With the cost of natural gas ...my guess is you will maintain a temp. With any amount of "stuff' in the space having it at a reasonable temp is nice and makes for quick and comfortable working. It can take forever to warm up a tool box

My well insulated 1600sf studio only has 40k and it costs me a few hundred bucks in the winter ---

In my experience....that "I will only run it when I need it" OFTEN turns into "leave it on but maybe turn it down to a low setting when I'm not out there" 8 times out of 10.

Phil

 

[Showkey]

With the cost of natural gas ...my guess is you will maintain a temp. With any amount of "stuff' in the space having it at a reasonable temp is nice and makes for quick and comfortable working. It can take forever to warm up a tool box

My well insulated 1600sf studio only has 40k and it costs me a few hundred bucks in the winter ---

This ^^^^^^^^^^^^ plus the add benefit of keeping the humidity levels in check with control of the temperature fluctuations.