Conventional heaters wont work,need alternatives.

[bc_stang]

ok guys i am planning on building 14'x 30'garage starting in june.I was talking to my electrician yesterday and after going through entire house's electric load,he strongly thinks i would not have enough left over amperage to run big heaters (mr freeze,etc) as it would put me over 200amp service that i currently have. He thinks by the time i get whole shop wired for hoist,welder,compressor,extra shop lights,etc there would be no room for ceiling mounted heater box as i originally had planned to install.

What are my options here?do you think radiat heat is the way to go even in a small shop? I personally thought(correct me if i am wrong) ceiling mounted heater would heat up small shop very quick compared to in floor heat...especially in a small shop i am planning to build.

Also i should mention that garage already has its own dedicated hot/cold water supply off of main house boiler(boiler is good for 7000sq.ft house), does a shop need to have its own separate boiler system or i can use same boiler from the main house?

 

[Mmfh]

Very popular around this site are the hanging unit heaters, gas or propane. Mine is propane , many here use the Natural Gas heaters hanging from the ceiling.

Mine works very well, runs on propane, uses very little electrical power. Your electrician would most likely say its fine to use one of these.

Search for Mr Heater, Big Maxx, Hot Dawg. Both good and popular units.

Mm

 

[bc_stang]

Thanks mmfh, I would like to look into those personally. He said those unit would req 30-40amp circuit because of the big fan. Maybe he's thinking about big commercial units?? I would have to do some research on the much smaller unit as I think it would do the trick in small shop.

 

[gt40mkii]

Personally, I'd try to avoid resistance heat. Around here electricity is the most expensive form of energy, hands-down.

I'l look at a natural gas or propane solution (in a small shop, even a small portable propane heater would do well, provided the shop was tight and well-insulated.)

Have you considered a wood stove? A good friend heated his shop with a small Jotul wood stove and it was TOO efficient -- we had to open a window to cool the shop a little.

 

[sneezer41]

I think your electrician is trolling for work. The 'big fan' probably draws 5 amps, at most it needs a 20 amp line

 

[Mike007]

I think your electrician is trolling for work. The 'big fan' probably draws 5 amps, at most it needs a 20 amp line

Yes, really. A 30 - 40 amp fan?

 

[dave67fd]

The Forced air gas heaters draw under 5 amps and don't need to be on their own circuit.
They can be on a shared circuit As long as they are not on a for example a "switched" lighting circuit or similar. Modines are a bit more money.

A 45,000 BTU unit will heat your 15x30 space with ease.
The Mr. Heater 45k unit is now under the "HeatStar" name but the same unit.

http://www.northerntool.com/shop/tools/product_200311447_200311447

You will need to install a 4" typical horizontal or vertical vent and run a gas line for these. Typical heater and installation cost can run aprox in the $1500 range for a licensed installer.

http://www.modinehvac.com/v2portal/page/portal/hvac/hvacResidential

This is my 75K unit.(vent and gas line NYI)

 

[dave67fd]

Have you considered a wood stove? A good friend heated his shop with a small Jotul wood stove and it was TOO efficient -- we had to open a window to cool the shop a little.

Although many do, It is illegal to use a solid fuel heating device in a residential/commercial "garage".

 

[Sureshot]

You already have the boiler. Run in slab or a unit heater using the hot water. I have a unit heater I wouldn't mind selling or make one from a rad. Insulate your lines well and bury an extra set when doing the install.

 

[rsanter]

first off if I was going to build a shop I would run the tumes in the concrete now even if I dont use them now. just in case you ever want to go that way.
how about you build a solar concentrator to collect the suns heat (yes even in winter) and a small pump to circulate the water through the hydronic in slap tubes.

next is why would you try to heat with electric? that is generally one of the more expensive ways to go. if you have natural gas I would use that with the secong option being propane.
to me the only reason to use electric heat is if you plan to install a big solar PV system

bob

 

[trainer]

If you are strating from scratch and have an existing boiler with enough capacity, then why would you look at anything other than in-floor radiant?

 

[Highbeam]

I've done the math and in my area(10 cent electric and 2.50 LP), electric resistance heat costs nearly the same as propane but electric is easier and safer.

If you have NG then that's great. If you can use a heat pump then that's great.

Solid fuel heaters are illegal in garages but a pellet stove, pellets are under 200$ per ton here, would be the cheapest thermostatic heater.

 

[dave67fd]

I've done the math and in my area(10 cent electric and 2.50 LP), electric resistance heat costs nearly the same as propane but electric is easier and safer.

You have to look at the requirements of the garage. Size, BTU's, how long you run the heater, what temp rise from ambient, how well insulated etc.. to compare usage and costs.

Solid fuel heaters are illegal in garages but a pellet stove, pellets are under 200$ per ton here, would be the cheapest thermostatic heater.

Pellet stoves are solid fuel heaters. Illegal as well.

 

[gt40mkii]

Although many do, It is illegal to use a solid fuel heating device in a residential/commercial "garage".

Well that's a stupid law.

 

[Highbeam]

You have to look at the requirements of the garage. Size, BTU's, how long you run the heater, what temp rise from ambient, how well insulated etc.. to compare usage and costs.

No you don't. You calculate costs on a $ per btu basis only. Those other factors just determine how many btus of either fuel you need and are the same for any fuel source so irrelevant in a comparison of costs.

I agree that a pellet stove is illegal in the garage. As I said, solid fuel heaters are illegal and pellets are quite solid.

 

[jvitez]

Hey, BC stang, does your moniker mean you're in British Columbia? If so, BC Hydro rates are probably way cheaper than propane, but what about NG rates? A NG unit heater would probably be cheaper than adding a fan coil forced air system run off your boiler, but a good HVAC contractor would give you the numbers.

If you are a Canuck, order this book:

http://www.psknight.com/

It's the CEC simplified. Do an electrical load calc yourself without the new garage. What amperage are you at? Now add every electrical load in watts not amps you could ever forsee using AT THE SAME TIME in the new garage. Divide this by 240, add it to the previous amperage calc. Are you over 200 amps? If not, you're fine.

 

[dave67fd]

You calculate costs on a $ per btu basis only.

Agreed.
My point was trying to calculate your real time heat costs are impossible without all the factors involved. "Comparision" of the two is as you mentioned irrelevant, my bad.

Regardless, for "comparison" cost it's cheaper and much more practicle for example using LP over electricity.

For example: 1 Gallon of Propane = 27 kWh (Kilowatt Hours) of electricity. This means that one gallon of propane contains the same amount of usable energy as 27 Kilowatt Hours. Or, 27 kWh equals approximately 91,500 BTU's.

So 27kwh @ $.10 per kwh=$2.70 vs 1 gallon of LP=$2.50

Historically, propane has been considered a better value and more cost effective when compared to electricity. Thats why it is so widely used nowadays. But yes, electric heat is considered more safe but quality of the installation is everything.

 

[2drx4]

For example: 1 Gallon of Propane = 27 kWh (Kilowatt Hours) of electricity. This means that one gallon of propane contains the same amount of usable energy as 27 Kilowatt Hours. Or, 27 kWh equals approximately 91,500 BTU's.

So 27kwh @ $.10 per kwh=$2.70 vs 1 gallon of LP=$2.50

However, even the cheapest of electric resistance heaters are 100% efficient, whereas most propane appliances are in the 80% (cheap) to 95% (very expensive) range. That just killed the difference.

That said, gas may well save you money (at least if using a forced air setup) in that it will bring the place up to temp much quicker, preventing you from being tempted to leave the heat on high when you're not around.

 

[ForceFed70]

Also i should mention that garage already has its own dedicated hot/cold water supply off of main house boiler(boiler is good for 7000sq.ft house), does a shop need to have its own separate boiler system or i can use same boiler from the main house?

Is your boiler gas or electric?

If it's gas, then there is no way you would be pushing the limits of your 200Amp service to heat your garage with electricity.

I also get the feeling that your electrician is trolling for work. If your garage is well insulated, you can probably get by with a 5000W heater. That's only 21Amps @ 240V.

 

[dave67fd]

However, even the cheapest of electric resistance heaters are 100% efficient, whereas most propane appliances are in the 80% (cheap) to 95% (very expensive) range. That just killed the difference.

Installation costs have to be included so you can calculate those into your figures as well.
Consider how many BTU's of electric heat to heat a 1000 sq. ft. area. A 5000 watt heater will produce a bit over 17,000 BTU's. I would need almost 4 of them to equal the BTU "Output" of a 75 k btu propane heater. A 75k BTU rated heater at 80% efficiency (input) produces about 60k btu "output".

 

[Highbeam]

However, even the cheapest of electric resistance heaters are 100% efficient, whereas most propane appliances are in the 80% (cheap) to 95% (very expensive) range. That just killed the difference.

Exactly. Your standard hanging garage LP heater is the 80% efficient type. Heck, even at 90% you still are better off using electric.

The fuel cost calculators available all over the net allow you to enter the efficiency of your heater to get a cost per btu that includes the efficiency variable. Don't assume anything. As you can see, even that ultra expensive electric heat can actually be the cheapest thing going.

I also like to at least consider convenience and future cost increases. Most everyone has electric piped to their home for an infinite supply and you already pay a bill that includes the delivery and base charge. With electric there is no running out, calling the LP company to come and fill your tank, or for him to start charging you tank rental or for him to raise his rates.

 

[gt40mkii]

Pellet stoves are solid fuel heaters. Illegal as well.

I'd love to hear the reasoning behind this law.

However, even the cheapest of electric resistance heaters are 100% efficient, whereas most propane appliances are in the 80% (cheap) to 95% (very expensive) range. That just killed the difference.

Depends on the relative fuel costs. Here in North Texas (yes, it gets cold in Texas too,)
electricity is MUCH more expensive compared to natural gas, making NG the fuel of choice for heating IF you have service.

 

[dirttracker18]

There is no way you should be going over your 200 amps. Something doesn't add up there unless you are running something out of hte ordinary that we do not know about.

I am stuck at 100 amps and have ample space left even heating my 1200 sq/f garage with an electric water heater. 100 amps is my house and garage combined!

 

[nehog]

...He said those unit would req 30-40amp circuit because of the big fan....

My 150K BTU propane heater (suspended from ceiling) draws 750 watts for the blower. The blower is strong enough to get the heat to the far corner of the shop, a 75 (approx) ft distance. A 15 amp circuit would work, wire with 20, but the load itself is minimal.

Find the heater you want, and the specs will list the power requirements. They are not that high.

 

[vartz04]

in the floor heat, if you cant get gas out there get the smallest tankless water heater and a pump to heat the water. There is only a few gallons of water in that 1/2" tubing in a garage that size even a tiny tankless heater can keep up with that demand.

 

[dave67fd]

Exactly. Your standard hanging garage LP heater is the 80% efficient type. Heck, even at 90% you still are better off using electric.

Your missing the point.

Your looking at 10cents per Kilowatt hour vs $2.50 per gallon of LP and nothing else. All your seeing is that elec. "LOOKS" cheaper. It isin't unless you pay alot cheaper elec rate or higher LP rate as the example which I doubt when it comes to the elec.

I also like to at least consider convenience and future cost increases.

What "Inconvienice"? calling on the phone to have your tank filled? What makes you think elec. costs don't increase?

Most everyone has electric piped to their home for an infinite supply and you already pay a bill

Infinite supply? So i should consider running three to four 5000 watt heaters @20+ amps each? (20kw=68kbtu's) to my 60kbtu LP?

Go back and do the math. I have nothing at all against electric heat. It definately has it's place. I would probably run it in a much smaller shop but to heat almost 1100 sq. ft it's downright useless.

Let me know of a commercial/industrial shop with significant square footage running electric heat. You won't find anyone doing it.

 

[dave67fd]

I'd love to hear the reasoning behind this law.

NFPA 211 says: No solid fuel appliances in residential garages.

It's because a "uncontrollable" flame is present were combustables are stored. (vehicles)

I believe there are some variances for a "properly" installed solid fuel appliance in "detached" garages. It is though quite specific for a "attached" residential "garage". Probably with regards to having overhead doors capable for a vehicle. I believe a closed (no overhead door) "shop" wouldn't be considered a garage as far as NFPA goes.

 

[kert]

Your missing the point.

Your looking at 10cents per Kilowatt hour vs $2.50 per gallon of LP and nothing else. All your seeing is that elec. "LOOKS" cheaper. It isin't unless you pay alot cheaper elec rate or higher LP rate as the example which I doubt when it comes to the elec.



What "Inconvienice"? calling on the phone to have your tank filled? What makes you think elec. costs don't increase?



Infinite supply? So i should consider running three to four 5000 watt heaters @20+ amps each? (20kw=68kbtu's) to my 60kbtu LP?

Go back and do the math. I have nothing at all against electric heat. It definately has it's place. I would probably run it in a much smaller shop but to heat almost 1100 sq. ft it's downright useless.

Let me know of a commercial/industrial shop with significant square footage running electric heat. You won't find anyone doing it.

Care to share your math?

 

[bc_stang]

wow sorry guys i could not respond as i have been travelling for the past couple of days. I must thank everyone for sharing their views and in return helping this newbie out!

first of all,yes i do agree my electrician is being...well just lazy imo.I have been noticing he wanna take the easy way out hence why i am here to discuss it on GJ. I did not wanted to tell him anything before doing some research myself.

I do have easy access to NG but would running in floor heat more economical compared to NG blower heater unit? Also other thing i need to know is- can i have multiple loads wired on the same line/circuit? for example can i have hoist,welding plugs and NG heater box on the same line? i think that shoudl be ok as i would not have all the items running at the same time.
Now i need to figure out how to make use of house boiler if i were to go with in floor heating. i do have hot/cold water coming from main house but dont the hot water need to circulate through in floor pipe and return back to boiler? i think end of the day installing a NG heater unit (especially if it only draws 5-15amps max) would be easiest but i keep hearing in-floor is the way to go so i dont mind going through extra work if it would give me better results.

other thing i need to do is calculate my total load. should i go to fuse panel and add up all the fuses? or go to indivisual load (washer dryer) and add up actual max load item draws in its specs?

 

[jvitez]

Yikes! Your last post has about a university-final-exam worth of issues to discuss, facts to learn, facts to use, and decisions to make! You're asking a bunch of different questions. Alright, I'll bite.

1. What type of heating system for your new garage.

Options: in-floor radiant. Forced air unit heater. Forced air ducted furnace. Ceiling or wall mounted electric radiant. Ceiling or wall mounted fuel burning radiant. 3 or 4 plug in portable electric heaters. Portable propane or kerosene heaters. Rubbing 2 Boy Scouts together. I'm sure I've missed a few.

2. Source of heat. NG, propane, oil, kerosene, electric.

How to decide? Answer these questions:

a. heating all winter and bumping up temps when you're out there, or just when you're in the shop?
b. What do you plan to do in there?
c. Where are you located?
d. What are your current costs for all fuel options you're considering?
e. Are you allowed/do you want to DIY any aspect of installing heat?
f. How large is your budget?
g. How flexible is your budget?
h. Do you currently have any preference as to which type of heating system you would install, cost NOT being an object?

Once you answer these we can help you a lot more. Details! We need details!

BTW, about your electrical questions: see my previous post. If you said where you're from we can help you much better. Do a proper load calc. Buy a basic book on home wiring. They all have a basic load calc in them. Buy one, read it, use it, do the math. We can't help you more in this. Once you have the actual load you calculated, everything is easy from there. Your electrician can't bafflegab you once your have hard data.

 

[dave67fd]

Care to share your math?

Go back and read post #17.

jvitez,
Good points.

bc_stang,
In floor heat is very popular and many swear by it. Has a high initial cost but maybe cost effevtive in the long run using NG/LP. Should be seriously considered especially if you plan to be on your back on the floor alot.

You need to keep all your high current devices i.e. 240V welders, hoists/lifts, elec heaters etc.. on their own circuit (breaker). NG/LP FA heater, depending on type/size can be on a shared 120V non-switched circuit (i.e.. not sharing with a "switched" light circuit.)

Take your time and continue to research all areas of interest. You will start to answer your own questions and will bring you closer to a decision. Don't rush it. You will be happier in the long run.

 

[dave67fd]

Rubbing 2 Boy Scouts together.

I don't even wanna ask what the hell is with that one.

 

[kert]

Go back and read post #17.

jvitez,
Good points.

bc_stang,
In floor heat is very popular and many swear by it. Has a high initial cost but maybe cost effevtive in the long run using NG/LP. Should be seriously considered especially if you plan to be on your back on the floor alot.

You need to keep all your high current devices i.e. 240V welders, hoists/lifts, elec heaters etc.. on their own circuit (breaker). NG/LP FA heater, depending on type/size can be on a shared 120V non-switched circuit (i.e.. not sharing with a "switched" light circuit.)

Take your time and continue to research all areas of interest. You will start to answer your own questions and will bring you closer to a decision. Don't rush it. You will be happier in the long run.

OK I looked at post #17. You use the same numbers that he does and come up with the same results, but seem to draw a different conclusion. I'm confused. At 90% efficiency for propane, it will take $2.78 ($2.50/.9) to get the same heat from propane that you would get from $2.70 in electricity. Am I missing something?

 

[Highbeam]

No you're not missing anything Kert. I also noticed that we all did that same math and figured I would let Dave sort of bow out after seeing the actual figures. Oh well.

When NG is in the mix, the LP vs. electric discussion is not worth having. NG is, and will continue to be for the foreseeable future, the cheapest way to heat if it is avaible to you.

Using NG to heat the space with forced air or with a radiant slab is a good discussion. Probably splitting hairs though.

 

[dave67fd]

Wow!! your "letting" me bow out? How kind of you. Your correct. I didn't include the efficency factors. Regardless, pricing can be very close depending on your region.

My main point all along. and i'll repeat, which no one seemed to question or take exception to.

I have nothing at all against electric heat. It definately has it's place. I would probably run it in a much smaller shop but to heat almost 1100 sq. ft it's downright useless.

Let me know of a commercial/industrial shop with significant square footage running electric heat. You won't find anyone doing it.

If elec. heat is so much cheaper why aren't they using it? Because it is "impractical" for a large space.

 

[vartz04]

In floor heat is cheap to run, whether you go with a natural gas or electric water heater to power it.

My dad has it in both garages and the basement. the pumps rarely run. Once you get a big slab of concrete hot it doesn't take much to keep it hot.

If you can easily run the hot water from the boiler out to the garage and won't have much heat loss in the pipes between the house and garage go for it. if not do what I mentioned before and run the smallest on demand (tankless) water heater you can. Even if you have 400 feet of pipe in that garage you only have like 4 gallons of water in the pipe (1/2" pipe end area * length = cubic feet and then convert that to gallons) Won't take much to heat 4 gallons of water to 120 degrees or so.

even something like this would probably work and only has a 12.5A draw.
http://www.homedepot.com/Plumbing-W...splay?catalogId=10053&langId=-1&storeId=10051

 

[6768rogues]

One of my buildings has a natural gas hanging furnace (Reznor) and it works great. It brings the building up to temperature quickly and doesn't cost much to run. Another building I own in another location has a similar furnace that is propane. It works well, too, but the propane is more expensive and it is a pain monitoring the tanks through the winter and making sure the driveway is not buried under snow when the propane truck pulls up. I wish natural gas was available there, I would change in a minute.

 

[BadgerBoilerMN]

Radiant heat is more comfortable and costs less to operate than any form of distribution (given the same fuel source).

You have a boiler and simply need a radiant manifold in the garage (after a proper heat load has been done to determine if the boiler has capacity to heat the garage.

Nobody wants an over-sized unit heater - short-cycling, using more fuel than necessary, blowing air and dust around with an open flame to boot!

 

[dave67fd]

Nobody wants an over-sized unit heater - short-cycling, using more fuel than necessary, blowing air and dust around with an open flame to boot!

Nobody? How about a properly sized unit heater- proper cycling, using the required amount of fuel, but still blowing air and dust around with an open flame.

 

[jonesmechanical]

Comparing efficiency and btu content and price per btu is simple. One good alternative would be a heat pump. It would provide heat and ac. Fujitsu has some larger units (4 ton) that put out a lot of heat (50,000+ btu's) are zonable (if you have an office) and their heat pump efficiencies are amazing some over 11.0 HSPF.

HSPF is the factor over resistance heat that it extracts out of a kilowatt in btu's. If you have a 10.0 HSPF rating, it will put out 10x's the heat than resistance heat, or you could say it is 1000% efficient, because if resistance heat is 100% efficient, a heat pump would be 10x's that.

They are also very effective in colder climates now to temps below zero. Also, you get air quality benefits with a filter, and the big one: AIR CONDITIONING.

No brainer. More money, but a foreseeable payback.