New Construction - Heating Advise

[87GN&98VET]

Hey guys, I'm constructing a new 1000 sq ft detached garage and trying to decide the best way to heat it. Location is SE Michigan so it can get quit cold.

I'm more of a hobbiest so I'll probably only be spending a few hours in the garage during the weekend through the winter. I've got some classic cars that will be stored - the cars will be hibernating and will not be pulled in and out of the garage over the winter. I am planning to insulate doors, walls and cieling. Goal is to be comfortable working on the cars over the weekend while avoiding my #1 fear of doing anything that could lead to rust on the cars.

I've done alot of research on this forum and I'm trying to decide between:

- Electric wall mounted heater. For electric I would only fire it up when I'm out there - doesn't seem to make sense to use electric to maintain a constent 50-60. Problem with firing up the heat when I'm out there is the risk of causing condensation to occur on the cold cars, eventually leading to rust.

- GFA wall mounted heater. This senario seems more feasible for maintaining a constant temp in the 50-60 range to avoid risk of rust forming on the cars and tools. However the operating cost would be more than using an electric heater only when I'm out there.

I've also considered floor heat but given the amount of time I'll be out there it would be hard to justify the initial cost vs GFA or an electric heater.

Am I being too paranoid about rust with senario 1? Is the maintenance cost of senario 2 worth it if I'm only out there 1-2 days a week? I appreciate your opinions!

Thanks,
Sean

 

[dave67fd]

Am I being too paranoid about rust with senario 1? Is the maintenance cost of senario 2 worth it if I'm only out there 1-2 days a week? I appreciate your opinions!

Yes.

So your intent is to keep it at a constant 50-60 deg? Why?
You will not have any moisture problems "unless" you heat with NON vented gas.

I've done alot of research on this forum and I'm trying to decide between:

Not trying to be critical but I don't think you have done enough research.

Heating your 1000 sq/ft with electric will/could cost you a small fortune.

You will/may need upwards of 75k-100k BTU's to heat this area adequately. Of course this depends on many variables. How well you insulate, your temp zone, how long and at what temp etc..etc..

For example:1 watt is equal to 3.41 btu/hr. So a 7500 watt electric heater will produce a bit over 25k BTU's. This may be adequate for you at times but may run for hours when the outside temp is very low. You would also need a 240 volt ~40-50 amp circuit.

Forced air or infared vented gas heaters may have a higher initial/installation cost (IR's being more expensive than FA) compared to electric but will probably suit your long run needs more adequately.

Just "some" examples
http://www.northerntool.com/shop/tools/product_200316428_200316428

http://www.northerntool.com/shop/tools/product_200316365_200316365

http://www.qcsupply.com/modine-hot-dawg-heater.html?gclid=COjCyfGEg64CFUlN4AodwTbh4A

http://www.northerntool.com/shop/tools/product_200316367_200316367

 

[HoosierBuddy]

The condensation problem is a function of the humidity in your area. I can remember firing up the heat in my barn on a cold spring day and seeing water start dripping off my car, mower, tablesaw, concrete floor, etc. However, the barn was completly uninsulated which may have had something to do with it.

I'd recommend a gas fired furnace or unit heater. They have super quick recovery which is great for part time heating. Do not use a vent free appliance or you'll make the condensation problem drastically worse. Use a vented wall heater, furnace or gas fired unit heater.

The only electric heat I would even consider would be a heat pump and then only if I planned on heating it 24X7 in a mild or moderate weather state. Heat pumps have extremely poor recovery and aren't suitable for part time heating like you propose. Resistance electrical heating costs roughly 4 times what natural gas does in most areas of the country.

Phil

 

[george2c]

Maybe this would be helpful. I have a 24 x 32 garage and use it kinda how you will use yours. I go out there 2-3 nights per week to tinker and drink beer. We have 3 ouellet electric heaters at work that I have been very surprised at how they work, so I bought one for my garage from northern tool. There are very few things in life that a person buys and are happy with, but this is one of them. I can go out there and turn it on and be 70 degrees from 40 in 1 hour. Mind you this winter in pa is very mild. Last winter was very cold and same results quick warm and comfy and no muss or fuss. I will attach the only pic I have of it but if you want moew just let me know and I will take some more.

 

[george2c]

ok here it is..

 

[george2c]

Forgot to add it is the 10,000 watt model because they do make a 5000 watt model. It is around 550-600 bucks.. Sometimes you can find a 10% off coupon.. Good Luck..

 

[tdkkart]

One of the things I've had a problem with in past garages is that when it was cold out I was unwilling to go out there when it was really cold simply because of the amount of time it took to bring the place up to a comfortable temp.
Yes, you can get the air temp up really fast if you put in a big enough heater, below zero to 70* in under an hour is doable with a mega heater from hell, however air temp really means squat when you want a comfortable work space.
Problem is, alot of things do not come up to temp nearly as fast as the air temp. Grabbing COLD tools, dipping your hands in a COLD parts washer, laying on a COLD floor, working with COLD machinery, these are the things that make working in a shop in the winter time really miserable.

Years ago I did alot of work in an uninsulated 2-1/2 stall garage. Go out, fire up the heat, go back to the house for an hour or so, back to the garage. I did this WAY too much, and it was a miserable way to get stuff done.
Next place we bought had a 2+ stall garage, plus an additional room on the back which I kept heated to 40ish all the time, and had on a programmable thermostat to bump it on a regular schedule. Still dealt with COLD floors, tools etc every time I went out there, and any big projects still required pre-warming the main garage area before I could work. Milling machines, lathes etc that weigh 1500lbs+ don't warm up very fast no matter what the air temp is, and when the floor is dead cold they NEVER warm up. Working with cold feet *****.
Present day, I have a dedicated 1200sf shop, heated continously with floor heat. It's not heated all that warm, but the difference is that it is comfortable because everything is the same temp. 55* is plenty warm to work in long sleeve shirt, and everything I pick up is a reasonable temp. It's hard to describe, but it's a way more comfortable work space than I've ever had before. The only small issue is that it's electric power heat so the bill jumps up in the winter, but when you spread it out over 12 months the average bill is reasonable.

Do your research and seriously consider heating the floor.

 

[george2c]

I agree, If I was working in a shop full time I would want in floor heat. I have some friends with that and it is awesome.

 

[metalTobman]

I think the best bang for your heating buck is a gas or propane fired overhead radiant tube heater. Reasonably efficient, quiet, and heats objects, not air.
I have two of these in my shop, and I keep the thermostat set at about
3C (37F) This keeps the chill out, and the machinery at an even temperature, nothing has to "thaw out" for me to use it. I find that I can work comfortably at this temperature as long as I keep moving.The fluorescent lights are dim and flicker for 5 or 10 minutes. I supplement the heating with an old wood stove that I built many moons ago, a couple of hours with that stoked up and the whole shop is comfortable, better yet the radiants don't have to run. Models of these heaters are available in low intensity for low ceiling heights, and also work very well.

 

[jhelrey]

In floor heat in a garage rocks! You can def. keep it cooler and you can tell the difference.

 

[hdshinn]

In floor radiant heating is notoriously slow with respect to recovery time, from cold to tolerable. It's not a "turn it on for the day" kinda heating system. It needs to be on all the time to reap its benefits. But a well designed system as has been pointed out will make a cooler than you might imagine working in environment quite comfortable.

We keep our house, the living space, at between 63 and 65 degrees. Granted we're in Western WA state with a temperate marine climate, but we do get spells of 32 and below weather in the depth of winter.

The initial cost may be higher than other options but the sheer comfort factor is, in my opinion, priceless.

 

[Chaz]

GFA would always be my choice.

 

[RKA]

Heat pumps have extremely poor recovery and aren't suitable for part time heating like you propose.

Phil

In the OP's situation, the climate is not moderate, so I agree with Phil, this is not the best solution. However for others that are reading, these heat pumps can be used successfully for part time heating. Most will have a programmable remote, so you can set it to turn on at 6AM the following morning if you plan to be out there around 8AM to work. The key there is moderate climate with little snow (high humidity and near freezing temps cause the units to go into frequent defrost cycles, which doesn't matter when you're trying to maintain temp but hurts when you're trying to raise temps). In my area, temps average in the 20's and 30's with less than half a dozen major snow events a season, and the heat pump does the job. The upside is low operating cost. Can't have everything. So far I'm finding when the ambient is below 20F and the inside temp is below 45F, the warm up times start to get prolonged (over 2 hours).

 

[theoldwizard1]

... Working with cold feet *****.

Present day, I have a dedicated 1200sf shop, heated contiguously with floor heat.
.
.
.

Do your research and seriously consider heating the floor.

+3 !

If you are going to work in the garage, radiant in floor heat is the only way to go !

If your only going to be working there for short periods, I would go GFA. With GFA, you will need to set it at a higher temp to be comfortable, and if you are on the floor, under vehicles, you will never be "warm".



Don't forget the insulation and vapor barrier under the floor !

 

[theoldwizard1]

... heat pumps can be used successfully for part time heating.

A heat pump's best feature is that you get cooling (A/C) for no additional installation cost ! This makes them unsuitable for radiant in floor heating.

Heat pumps are fairly expensive, but the heating AND cooling capability makes it worth the money. The most efficient heat pumps are

. Even more costly to install, but the pay back in their efficiency.

 

[jhelrey]

My buddy had in floor heat and a furnace. He keeps the IFH on all winter and the furnace when you want the quick warm up of the air.

 

[87GN&98VET]

Good stuff guys. Thanks for all the opinions! Based on my needs and initial cost I'll probably end up going with GFA.

 

[mustangcrazy77]

I think the best bang for your heating buck is a gas or propane fired overhead radiant tube heater. Reasonably efficient, quiet, and heats objects, not air.
I have two of these in my shop, and I keep the thermostat set at about
3C (37F) This keeps the chill out, and the machinery at an even temperature, nothing has to "thaw out" for me to use it. I find that I can work comfortably at this temperature as long as I keep moving.The fluorescent lights are dim and flicker for 5 or 10 minutes. I supplement the heating with an old wood stove that I built many moons ago, a couple of hours with that stoked up and the whole shop is comfortable, better yet the radiants don't have to run. Models of these heaters are available in low intensity for low ceiling heights, and also work very well.

X2 on this.

Having had a 1000 sq foot hobby garage in mid-Michigan, I can attest to the benefits of using a Radiant tube heater. The beautify of IR heat is...you don't need to heat the shop up to 65+ degrees (air temperature) to be comfortable (as you would with forced air). Keeping the garage constant low 40's through the winter and turning it up to low-mid 50's when working ensured low heating bills (around an extra $50/month). The best part was, the tools and the floor were never ice cold. FYI, mid 50's with a radiant tube heater is quite comfortable. You'll start off with a sweatshirt and end up in a T. Another added benefit is...when you open the garage door, you don't have to worry about losing all of the precious heated air (remember, the heater is working to heat the object's in the room, not the air).

Having said all that…if I still lived in the frigid tundra I would only consider 2 choices for heating a larger garage, a gas fired IR tube or in-floor radiant. Fortunately…I don’t, as it was in the mid 70’s down here yesterday.

 

[Stuart in MN]

My buddy had in floor heat and a furnace. He keeps the IFH on all winter and the furnace when you want the quick warm up of the air.

I think this would be the ideal solution if it fits your budget. Keep the infloor heat turned down to 50 or 55 or whatever, and then turn on the heater if you want to warm it up quickly while you're working out there.

It may be worth finding someone in your area who has infloor heat in their garage so you can see how it feels. A friend of mine has it in his garage, and even when it's turned down pretty low it's still quite comfortable because of how radiant heat works - it's kind of funny, you can tell the air in the room is cool but your body still feels comfortable. And, of course having a warm floor is really nice - standing on cold concrete really ***** the heat out of your body.

edit: overhead tube radiant heat works good also, but you have to be careful to get the right kind for a residential garage - many of them are designed for high ceilings in commercial garages.

 

[HoosierBuddy]

So far I'm finding when the ambient is below 20F and the inside temp is below 45F, the warm up times start to get prolonged (over 2 hours).

I had a conversation with a church the other day that had 6 heat pumps and was getting power bills over $2000 per month in the winter. In response, they had instituted a very rigerous "turn down" program at nights to try to save money and saw their power bills INCREASE rather than decrease. A little investigation showed that what was happening is the emergency heat strips were coming on each morning when the t-stat setting was increased to bring the building up to temp. This reduces the COP of each unit from something in the 3.5 range to 1.0...meaning THE UNIT USES OVER 3 TIMES AS MUCH POWER TO PRODUCE 1 WATT OF USABLE HEAT when you try to run it in "part time" mode.

Maybe all heat pumps wouldn't react that way...but I think they will. If you let the building cool off 20 degrees and then kick the t-stat...it will bring in the heat strips regardless of outdoor temperature. I'm not a heat pump expert...so if I'm confused on this, somebody let me know.

I also agree that 24X7 heating is fantastic. However, it isn't in everyone's budget. It costs real money to heat a garage all the time. Insulation is a must. Even if it's not a lot of square footage, if the walls, windows and doors are uninsulated...it'll cost a small fortune to heat it. (The reason I know this is people who try this call be complaining that their gas bill is too high. After 100 or so such calls, I've recognized the pattern.)

Phil

 

[curiousB]

Going back to OPs original post. I would recommend a vented natural gas ceiling hung unit. I have the Mr. Heater 45k but the Reznor and other brands are identical.

In slab heat is the best but it has to be kept on 24X7 and as an occasional weekend warrior I just don't need to waste $$$ to heat for the odd day here and there.

Stay away from vent free gas units as they plow moisture into the space (think rust) and I swear they make you noxious (I had a vent free and yanked it out).

I have loved my Mr Heater 45k BTU unit. Its into year 3 and no regrets. From 20 degrees to 65 in about an hour for a 3 car attached garage (good insulation and warm space above).

NG is 3.5X less expensive than electric in my area for the same BTUs.

Also electric has some hidden costs in that for high wattage units you have to run a beefy branch circuit and possibly conduit from the main panel to feed it. About the same effort as running a gas line.

 

[RKA]

I had a conversation with a church the other day that had 6 heat pumps and was getting power bills over $2000 per month in the winter. In response, they had instituted a very rigerous "turn down" program at nights to try to save money and saw their power bills INCREASE rather than decrease. A little investigation showed that what was happening is the emergency heat strips were coming on each morning when the t-stat setting was increased to bring the building up to temp. This reduces the COP of each unit from something in the 3.5 range to 1.0...meaning THE UNIT USES OVER 3 TIMES AS MUCH POWER TO PRODUCE 1 WATT OF USABLE HEAT when you try to run it in "part time" mode.

Maybe all heat pumps wouldn't react that way...but I think they will. If you let the building cool off 20 degrees and then kick the t-stat...it will bring in the heat strips regardless of outdoor temperature. I'm not a heat pump expert...so if I'm confused on this, somebody let me know.

Phil

LOL! I'd blame the installer for not educating them on the consequences of a high set back temp. In my case (no heat strip), with an ambient of 25F and inside temp of 45F, my unit will consume 3.7kw over the first hour or so, then settle back to an average of 1-1.5kw to maintain 62F. As the ambient and garage temps drop, the equation gets worse and it's not linear. The heat strips just add resistance heating. In my case, in dollars and cents, it's about $0.80 to get the space up to temp, and <$0.20/hr to maintain. If someone wants more elaboration performance and cost, they can PM.