Discussion Forum - Northstar Chevelle Club

SShink · 3K+ Club

Radiant vs. Forced Air Heater for attached garage

dashboard · 2K+ Club

Check your links Stan.

Lost in the 60s · President

Stan, the radiant is going to be more intense and may get too hot for nearby objects too close to the front. The radiant tube in my shop "throws" a lot of heat down without a fan.

The ventless may not be as efficient as the radiant, but with the optional fan, will circulate the heat. The radiant can have the fan too, but, again, may be too intense for things in close proximity.

Bobs_Place · Vice President

Stan I agree with Mitch, I was told when trying to decide on heat for my attached garage, unless you have enough height, radiant would not be a good choice. They said you might bake the paint on the roof of the car???

I put in an oversized hanging forced air in the attached. My 1st garage the heater was sized to the footage by the heating/ac companies guidelines. Took 3-4 hours to bring heat up on a cold day. In my current I went with a higher BTU than recommended. At the time I did not heat during the week so getting the heat up quickly on the weekends was important. I now spend much more time in the garage during the week, heater runs very little to recover. Been very happy with this heater.

If your not going to spend much time out in the attached but plan to heat all the time your need would be different, I would however oversize some.

dashboard · 2K+ Club

Radiant is a great way to go but you need ceiling height. I would avoid a ventless system as they generate a lot of condensation inside. Check local codes, they are not within code in several locations. Bob’s explained it well, overhead forced air vented, best bang for the buck. Electric baseboard heat another option if your going to keep it heated.
If you lack insulation in the over head, be ready for ice dams if you heat the space below.

SShink · 3K+ Club

Sorry about the links not working. I can't get them to work from the Northern Tool site. Anyway, they weren't ceiling mounted units but ones that either sit on the floor or mount to the wall. They range in price from $165 for 30K BTU's for either style.

Here's the forced air one:

Mr. Heater Natural Gas Vent-Free Blue Flame Wall Heater â 30,000 BTU, Model# MHVFB30NGT

I didn't think about the moisture issue with not having venting, and some of the user feedback was from being in garages but nothing related to any moisture issues. I suppose that could be a problem, although with the garage door opening so much, there's fresh air in a lot of the time.

Anyway, just looking for a lower cost way to heat the attached garage, and already have the gas line there so just trying to be too cheap probably.

Kevin-The ceiling is drywalled with a vapor barrier but you're probably right about the heat passing through and causing ice dams potentially.

Lost in the 60s · President

I got the links to work, they just didn't go to a specific unit. I actually looked at them last fall for our attached garage.

Yup, no insulation in the ceiling is going to turn into a LOT of run time to keep a decent temp. Maybe spend the money to get that insulated well with blown in fiberglass. Our house was a model originally, and the garage is fully rocked and insulated and it stays above freezing for all but the coldest period of January. Even then, it never drops lower than the mid twenties, so it's not terrible.
For the occasional need for heat for a repair, you could get a small torpedo heater and run it on a propane tank. I got one last year to warm the shop quicker and a 30,000 btu model would about toast you out in an hour. I have to shut mine off after an hour as it's getting too warm in there with both sources of heat going. Before the torpedo, it would take an hour to get even close to comfortable with just the indirect.
Pretty sure I only paid about $100 for the torpedo on sale at Menard's...

cooz65 · Webmaster

Mitch how is that torpedo heater, that's one of the ones I've been looking at? I've been looking at different options as well to heat my garage this winter. Exactly what Stan was saying, just something to take the edge off when the occasional oil change, brake change, weekend project, etc. Biggest downfall I've heard to the torpedo heaters is that they are really noisy and somewhat annoying to work by.

SShink · 3K+ Club

cooz65 wrote:
Mitch how is that torpedo heater, that's one of the ones I've been looking at? I've been looking at different options as well to heat my garage this winter. Exactly what Stan was saying, just something to take the edge off when the occasional oil change, brake change, weekend project, etc. Biggest downfall I've heard to the torpedo heaters is that they are really noisy and somewhat annoying to work by.

I have the same one Mitch posted about, and have used it for weekend work in the garage. The fan is loud and noisy, but heats the garage pretty quickly and I had to turn mine down or off once it reached a decent temperature inside. Worth the money for short term heat like Mitch said.

more ambition than brains · 1K+ Club

Best $$ spent would be insulation and sealing all doors.
Our garage in the last house was fully insulated and rocked, never got even close to freezing.
Had one common wall with house.
Pretty easy to elevate temp when well sealed and insulated.
Warm engine will generate enough heat to melt snow and ice off cars.

May want to look at the small, vented, permanently mounted gas unit heater, with a thermostat.
Guessing 80-125000 Btu.

The furnace GURU's should be able to add to other comments.
Where is Chris R. when we need him?

Karl

dashboard · 2K+ Club

If you only need it to take the edge off you might look at electric, if your panel is close by it would be a a quick install. 7500W = 25500 clean quite dry BTUs.

www.menards.com/main/heating-cooling/heaters/electric-garage-heaters/profusion-reg-heat-garage-heater-7-500w/eh-4604b/p-1444432294118.htm

I have one in my 20x25 shop it will make the space comfortable in an hour. Your climate is a little harsher but we do get -20s. I think JH has a similar unit.

Larry Lucast · Active Member

My garage is about 1,000 sq. ft. and pretty well insulated and sealed. It is "L" shaped, with the inside of the "L" shared wall with the house. On really cold days, it takes at least an hour to warm up. But it does get nice and warm.

SShink · 3K+ Club

dashboard wrote:
If you only need it to take the edge off you might look at electric, if your panel is close by it would be a a quick install. 7500W = 25500 clean quite dry BTUs.

www.menards.com/main/heating-cooling/heaters/electric-garage-heaters/profusion-reg-heat-garage-heater-7-500w/eh-4604b/p-1444432294118.htm

I have one in my 20x25 shop it will make the space comfortable in an hour. Your climate is a little harsher but we do get -20s. I think JH has a similar unit.

Unfortunately the panel is on the opposite end of the house in a finished basement.

Larry, do you have natural gas or electric heat?

SteveS · Super Poster

I have 2 of the ventless type like you're showing. Both are in single car garage size buildings. They will heat the space, but when you're burning anything indoors, there really isn't such a thing as ventless. I have to crack a window or you will start to feel the carbon monoxide before too long. Maybe with a bigger building, or one that isn't as well insulated it wouldn't be a problem, but if I had to do it again I would go with a chimney.

SShink · 3K+ Club

Thanks everyone for the feedback.

Well, the garage heater discussion just got put on hold. While having a Fall checkup yesterday on our 20 year old home furnace, they discovered there are 2 cracks in the heat exchanger. At the same time a couple of other parts decided to go bad while he was working on it, but he got it limping along so that we can at least have heat until we can get it replaced. He checked for any CO2, and all is good at this point, but I want to replace it asap.

We knew this was possible, so I had signed up for the replacement assistance program through Centerpointe, and that will pay for about 1/4 of the replacement cost, but still helps. And, I can use any company I want to use, so I don't have to go through them. I'm going to get 3-4 quotes and go from there. Found Steve's Heating in East Bethel about a mile from my house, and my boss has used them with very good results, so hopefully that will work out. Working from home today so that I can be around to get quotes.

Let me know if anyone has any other good HVAC companies they've worked with in the NW metro.

Enganeer · Mega Poster

Saw this one. It's setup for propane butI would think you should be able to convert to NG.

www.facebook.com/marketplace/item/770245956660039

SShink · 3K+ Club

Enganeer wrote:
Saw this one. It's setup for propane butI would think you should be able to convert to NG.

www.facebook.com/marketplace/item/770245956660039

Thanks John. Pending sale already when I reached out to the seller.

Chris R · 2K+ Club

I prefer forced air heat in a home shop vs. radiant because I like the consistent amount of heat throughout the garage. Radiant heats up the objects in the space which takes time & energy to do so but I prefer the air in the shop to be warm so I like forced air. Which I still need to install a brand new 75K Beacon/Morris unit ive had sitting in the box here since August to replace my 50 plus year old Modine which is a complete monstrosity that hangs in the way but heats up the shop nice and still keeps on ticking.

BLyke · 1K+ Club

Chris R wrote:
I prefer forced air heat in a home shop vs. radiant because I like the consistent amount of heat throughout the garage. Radiant heats up the objects in the space which takes time & energy to do so but I prefer the air in the shop to be warm so I like forced air. Which I still need to install a brand new 75K Beacon/Morris unit ive had sitting in the box here since August to replace my 50 plus year old Modine which is a complete monstrosity that hangs in the way but heats up the shop nice and still keeps on ticking.

yep, good comments on the forced air

My Shop has off-peak electric, forced air. cost is about the same as gas to operate (or is least it was when installed)

Lost in the 60s · President

Stan, go get Larry's furnace and get a new circuit board...be about the cheapest route for now.

On the home furnace, get one with a stainless heat exchanger and you'll never have to worry about cracks again. We paid a little more for our Goodman when we replaced 10 years ago, but it still looks like new inside.

I would also get a second opinion on the cracks, unless he showed them to you and you could actually see them. When the tune up guy told me our exchanger was cracked, I said I need to see and it was the seam in the casting. I couldn't see a crack but the jerk insisted he had to red tag the furnace and shut it down, after the new one was in I had the guy that took the old one out pull it down far enough to see the exchanger from the outside and there was NO CRACK...it was a scam to make a sale. I didn't go with the company that I hired for the tune up and was glad I hadn't. I called the owner and chewed him a new navel, but I'm sure it made no difference to him.

SShink · 3K+ Club

Yeah Mitch, the thought crossed my mind that the tech pulled up some pics from a different furnace. He did text them to me, but I haven't gone to the trouble to determine when they were taken since we had planned on replacing this 20 year old furnace anyway, and need to do something sooner than later.

When talking about the cracks with the local shop I found, he did tell me there was a tech in the Cambridge area doing exactly what you described, and it finally caught up with him. Unfortunately, they are out there.

Lost in the 60s · President

Just a thought, but have your local guy take a look. If you don't need a new furnace right now, spring/summer is a better time to replace and possibly a better price. Set some money aside over the winter.
We were in a similar situation, where ours was 25 years old and not high efficiency. The A/C was undersized for the house too, so we just had it all changed out, but it was deep November and the furnace had to be up and running the same day. In mild weather, that isn't an issue.
I was, also, running OTR at the time and didn't want to worry about this when 500-1,000 miles from home. You may have a similar concern.

SShink · 3K+ Club

I attached pics for those that are curious what I was shown on the cracks, although they're pretty zoomed in on so they look bigger than they are. The tech was into the furnace for quite awhile, so if it was a scam he spent a lot of time making it look good. He even dug out an old torn portion of an air filter that was jammed in the cold air return full of dog hair. My gut tells me the cracks are real, but I could be wrong too.

We scheduled the furnace replacement for the Monday after Thanksgiving, so will limp along until then. I'm not going to get anymore opinions on the cracks as we planned on replacing the furnace anyway due to it's age and safety concerns.

dashboard · 2K+ Club

When borescoping a jet engine turbine we would slip in a piece of .020 safety wire next to the crack to get a sense of scale.

Enganeer · Mega Poster

Looks like it is cracking out. I just had the garage heater (modine) at the northern house checked and he saw a line in the heat exchanger and used a pick to drag across the line to check if it was a crack. Pick did not catch anything and upon further examination / view point, it was just the seam.

-- Edited by Enganeer on Friday 16th of November 2018 02:40:49 PM

jim larson · 2K+ Club

Garage is 952 sq ft, height 9". Insulated walls, doors, and 8" in ceiling. First went the cheap route with a radiant ventless. Mistake!!! Vented natural gas Modine now, works fine, wish I could find a thermostat to go down to 40 degrees when not working in garage.. If I were building a new unattached garage it would have 30" in ceiling and 6" in wall and a mini split AC with inverted heat, and electric heater for when the temperature drops two low. Those high efficiency furnaces are not all what they are cracked up to be. Online calculators at not reliable to determine your savings. My furnace is a 40 yrs old boiler and still giving me about 70-75 percent efficiency. Cost for heat in a 100+ year old house with updated windows and added insulation runs about $1000 for both the 2 story house at 1800 sq ft and 952 sq ft garage. I figure it would take 40-60 yrs to pay for the $7000 new high efficiency boiler. Then add in the high maintenance costs. Radiators with bathroom at 80 when I get up in the morning. Sleeping temp is 65.

SShink · 3K+ Club

jim larson wrote:
Garage is 952 sq ft, height 9". Insulated walls, doors, and 8" in ceiling. First went the cheap route with a radiant ventless. Mistake!!! Vented natural gas Modine now, works fine, wish I could find a thermostat to go down to 40 degrees when not working in garage..

Jim, what didn't you like about the radiant ventless heater?

I've been told the good old circular Honeywell mercury thermostats work well in a garage if you want one that will go that cold for setback. I found out the hard way that electronic ones only go to 40 degrees when one cold morning after just putting the heater in the shop in Rosemount it got down to 32 degrees and the thermostat quit working so the heat wouldn't turn on. Had to drag out the propane heater to get the temp up enough for the thermostat to kick on the heat.

dashboard · 2K+ Club

Jim check your PMs for a 40-80 degree thermostat.

Lost in the 60s · President

Just got a Northern flyer with a 17,000 BTU, ceiling mount for $90...

SShink · 3K+ Club

As I walk by the sad looking Malibu without it's hood on and the crate engine sitting 2 ft away...I keep coming back to getting the house garage heated so that I can work on the Malibu. My biggest hangup is having to put the gas heater exhaust tubing either through the side wall or ceiling/roof, and I'm not comfortable with that part of the install (especially now that it's so cold!).

After being at Karl's Bowtie Brunch and enjoying the warmth of his radiant NG heat, I started looking at it again and landed on this for $300 at Northern Tool:https://www.northerntool.com/shop/tools/product_200455645_200455645

From everything I found it's considered 'ventless' as long as there's some natural air flow in the space, which should be enough from the air leaking around the garage doors and as frequently as they open and close every day. to bring in fresh air. I have 12' ceilings, so have enough for the clearances above and below the heater.

Worst case on the venting, I could put in a bathroom style exhaust fan in the ceiling above the unit as recommended by the mfg:

"This heater does not require direct venting with a flue but does require venting in the building to dilute the products of combustion and provide fresh air for combustion. Power ventilation such as an exhaust fan in the ceiling located near and above the location of the heater is recommended. Exhaust fan is not included with the heater and must be purchased separately."

Install should be easy enough since my gas line is already run to the ceiling and I just need to add a sediment drop and flex connection line. Electrical is fairly close as well.

Other than Jim's negative comment about radiant heat, anyone else see any concerns about using this in a garage that has insulated side walls (I'm going to insulate the ceiling this Fall), and would keep it around 40 degrees most of the time and only run it around 55-60 degrees on the weekends when working in the garage, so it wouldn't cause too much heat loss through the ceiling to cause roof/ice dam issues? I ran through one full winter in the other shop I had with only 3/4 foil insulation on the ceiling all winter, and didn't have any issues with that.

jim larson · 2K+ Club

I put a infared unit in with no vent. Used it 3 months Created way to much moisture. Unattached garage like yours, 900 sq ft, not as tall as your garage only 9’ ceilings. I would be careful about running with no outside vent.

Bobs_Place · Vice President

Have you checked with the city? Will they allow any type gas heat with out venting? How big is this garage and is it attached? My first garage was 22*24 well insulated walls and sealing and attached. The heater was a 50,000btu, and took a long time to bring the temp up. I am skeptical that 40,000btu be enough while your out in the garage.

Chris R · 2K+ Club

Richard from This Old House installs one of those on an older episode.

https://www.thisoldhouse.com/how-to/how-to-heat-garage-workshop

Lost in the 60s · President

Give it a few more weeks to get past the coldest part of winter, then fire up the portable propane heater you already have and get that engine in. I have one too, that you could use, to heat up the garage quicker/better.

Normally, I would not be concerned about a city ordinance, but that subject does bring up a concern for insurance. IF a heater were installed bootleg and you had a fire, would the carrier deny coverage based on that install ????

SShink · 3K+ Club

All good questions. This is for the attached 3 car garage, not the detached garage (I'll deal with that one this summer/fall).

I'm guessing insurance wouldn't cover anything on a home owner installed unit unless it was professionally installed. To be on the safe side, that's probably what I'll do. I'm just being cheap...

Enganeer · Mega Poster

I would wait and get a one of those Big Maxx NG units. I have a 75K Modine up north and heats a 30x35 pretty good.

This one is on sale at Northern Tool.

https://www.northerntool.com/shop/tools/product_200577751_200577751

-- Edited by Enganeer on Wednesday 23rd of January 2019 09:19:36 AM

bowtie · Secretary

We have radiant at work, but in a much larger space. I like it, though it seems very directional (like LED bulbs are) where you can really feel when it is on, but only in direct line with it's aim. I would think forced air is OK, but heats the air so it probably takes way longer for materials to warm up?

I have electric baseboards in my garage. I typically flip the breaker on in late November and keep the t-stat at whatever minimum temp it has unless I go out there. I don't have a large door open much, so it keeps a pretty constant temp, but can take a little bit to make up if an overhead is open. I have a ceiling fan, and it takes maybe 10-15 minutes to go from 40-65 when I turn it up. Not what you were asking, but in case someone runs across this later.

jim larson · 2K+ Club

If you have the cash I would install one of those mini split heat and AC units. Some work down to -14 and install a couple of electric baseboards units for weather like today. Maybe you could jack hammer out the floor and do radiant hear.