Any HVAC guy's out there?

charley95

Have a question concerning getting a little extra heat to my garage. I have a 20 By 22 attached garage well insulated and very tight. I was thinking of maybe tying into one of my existing ducts from my basement and run to garage. On very cold days it gets no less than 40 degrees and when it's in the 30's outside it stays at 50. In the summertime I would close off the vent to garage when the A/C is on. I don't need it to be 70 out there but, would like it a bit warmer than 40 on days like today. Is this a bad idea?

charley95

The garage is my man cave and I'm out there all the time and don't want to hassle with a space heater. Floor space is minimal with 2 cars in it with a large workbench and tool chest.

tonyb

Run a gas line and hang one from the ceiling. Just running a vent won't do much as the furnace will only kick on and off by the thermostat in the house. So the house can be at 70 and the garage still at 40. You need something thermostatically controlled for the garage. They also make ones that hang on walls too to conserve floor space.

jeremymarcinko

In addition to what Tony said, you will also need a return in the garage. If not, there will be more positive pressure in the garage which will make it more difficult for the blower to force air in that space. Also , at the same time you will be depressurizing the house, which will make it draw in more cold air from outside, making the home insulation much less efficient. If the hvac is large enough you can hear that space but you will also need a return, or keep the garage door to the house open.

charley95

Thanks everyone! I didn't even think about the cold air return. I already ran a gas line behind the wall when I remodeled it a few years back. I just didn't want to hassle with putting a gas heater out there when it's at 50 on average winter days. Wall mount is something to think about. I usually pop the hood on one of the cars after being driven for a short 5 degree increase. Are the wall mounted heaters expensive to run? The only time it wouldn't run is when I go to bed at night or away from home for extended times.

tonyb

Depends.....like every furnace it depends on where you keep the thermostat at. Turn it on 30 minutes before you want to be in the garage for extended periods, shut it down when your not. Gas is going to be the cheapest form of heat anyway.

charley95

Great advice! Thanks guys!

gdb

Don't run a return duct from the garage...... as long as there are internal combustion engines in that space. (for obvious reasons) Your fire codes and insurance restrictions would forbid it, I'm pretty sure. Radiant quartz heaters would be my suggestion.....

trav0810

Depends on your budget. I'm a big fan of the Mitsubishi "Mr Slim" heatpump units. But that is really only a good option if you are wanting cooling as well as heat.

rpf65

Even though it is more expensive to run, I would probably recommend an electric heater. There are quite a few wall mount styles available. Reason is pretty simple.

The most common type of wall mount heater needs to be vented, a flue pipe. These are oval shaped, because they are designed to fit into 2x4 framed walls. Problem is you need to get the burned gas fumes outside the space. These things just aren't hung and started, there is a little more to them. If you decide you want to go this route, I would get a 750 mV type one. They work well, and require no electricity what so ever. Professionally installed, best guess would be 1800 to 2500 range, depending on where you live. Call this a standard 35k BTU.

There is also ventless type wall heaters. Probably the most popular place for these is in your mechanics garage, hanging up by the ceiling. They have different types, including wall mounted. These don't require a flue pipe to be run for exhaust gas. Problem is you're local building codes. You may or may not be able to use these in your application, have to ask an AC contractor, not a general contractor. Couldn't give you an estimate on these, usually commercial applications, and I work residential.

They have wall mounted electric heaters. Probably 3KW will be big enough for your needs. It will require a 240V wire run, but surface mount it inside your garage to save costs. They have conduit that doesn't look like piping for interior use. Again, I would recommend professional installation. Best guess on this one would be 700 to 1K range, depending on if a licensed electrician is required to install and connect a breaker.

jeremymarcinko

I would look for a nice used wood burning stove. I had one in a detached garage many years ago. I really liked it, it would put out a tremendous amount of heat although takes a little effort, but doesn't hardly cost a thing to use. I can remember many nights out there with the brothers and cousins, sippin a few. Cooked lots of beans and chili on top of it too.

WilliamM2

I use one of these:
http://www.amazon.com/gp/product/B0002VG3H6/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Paid $135 for it in 2007, this brand is no longer available, but you should be able to find something very similar. I had to spend another $150 of so for CSST corrugated tubing and fittings to install it, but since you already ran the pipe you shouldn't need much, and you're halfway done already. It was quite easy to install myself.

I have a 26' x 28' garage with 12' ceilings. When it's 20 degrees out, it takes about an hour to reach 60-65 degrees, although my garage is very well insulated, including the door.

tonyb

That's exactly the unit I was describing...^^^^, perfect for garages. Electric quartz heaters will cost a fortune to heat that space.....anything electric actually.

charley95

WilliamM2 wrote: »

I use one of these:
http://www.amazon.com/gp/product/B0002VG3H6/ref=oh_aui_detailpage_o00_s00?ie=UTF8&psc=1

Paid $135 for it in 2007, this brand is no longer available, but you should be able to find something very similar. I had to spend another $150 of so for CSST corrugated tubing and fittings to install it, but since you already ran the pipe you shouldn't need much, and you're halfway done already. It was quite easy to install myself.

I have a 26' x 28' garage with 12' ceilings. When it's 20 degrees out, it takes about an hour to reach 60-65 degrees, although my garage is very well insulated, including the door.

And here I ran the gas line from the basement to the attic. At first I thought I was going to do a ceiling mount forced air furnace. I then decided that was overkill for such a small space. Of course the gas line now is buried in spray foam in the wall and finished over with drywall. I think I'll wait and decide next winter what to do. In the process now of a pricey kitchen remodel and don't need another project at the moment.

westmassguy

gdb wrote: »

Don't run a return duct from the garage...... as long as there are internal combustion engines in that space. (for obvious reasons) Your fire codes and insurance restrictions would forbid it, I'm pretty sure. Radiant quartz heaters would be my suggestion.....

Agreed, national fire code and quite sure local and state codes would forbid this.
Do not use vent-less gas heaters, they're illegal in my state for good reason.
If you do go that route, make sure you have CO and O2 depletion sensors/detectors

gdb

There are combination, window a/c-heat pump units available if you've got a window or if you can frame an opening in the exterior wall.

mrbigbluelight

IMO, anything with a flame is going to need 100% outside air for combustion,
Anything less leaves you open to a "Puff the Magic Dragon" event, ie, any small gasoline leakage from your vehicle can cause a BIG "Holy Cow" incident.

WilliamM2

mrbigbluelight wrote: »

IMO, anything with a flame is going to need 100% outside air for combustion,
Anything less leaves you open to a "Puff the Magic Dragon" event, ie, any small gasoline leakage from your vehicle can cause a BIG "Holy Cow" incident.

Gas heaters have an open flame, I'm not sure how using outside air for combustion would stop gasoline from igniting.

For safety, I have mine mounted about 15 feet from any vehicle, and I never let it run unattended if there is a vehicle in the garage. I also store gas cans for the lawn equipment in my shed, not the garage. Don't have to worry about knocking a can over that way. But I did that even before installing the heater, I don't like the idea of storing gas in the same building I sleep in.

MetropolisLake

gdb wrote: »

Don't run a return duct from the garage...... as long as there are internal combustion engines in that space. (for obvious reasons) Your fire codes and insurance restrictions would forbid it, I'm pretty sure. Radiant quartz heaters would be my suggestion.....

We looked at several fairly nice houses before we ended up building, if they did have a register for the garage, they never had return air. You don't want to constantly heat the thing as if it is an inside room anyway, you just want to take the edge off of extreme temperatures. Even if toxic air wasn't an issue, add a return air and actually heat the space as if it is a room and you will lose a ton of money due to heat loss through the concrete floor and drafty overhead doors. There were two houses that did this after converting the garage and back porch into a permanent living space and the heating bills were just ridiculous. One literally racked up nearly $1,400 in heating bills within a month and a half. They emptied two 500 gallon propane tanks plus $200 worth of electricity from a second service that heated the upstairs.


http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/56495/Want-Bad-Air-Put-a-Heating-Cooling-System-in-Your-Attached-Garage

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/68883/Are-You-Making-These-Mistakes-with-Your-Garage

gdb

IF....I were fortunate enough to have a garage, I'd use one of these to heat it. I use one in my uninsulated shop building (20' X 30') with a box fan up in a corner of the ceiling for circulation. Works great and it really doesn't smell because I always light it and extinguish it outside the building. Some areas do not permit these but, fire averse Japan has em everywhere......... (just keep a window cracked a little for fresh air exchange)

westmassguy

Those are illegal in my state

charley95

MetropolisLake wrote: »

gdb wrote: »

Don't run a return duct from the garage...... as long as there are internal combustion engines in that space. (for obvious reasons) Your fire codes and insurance restrictions would forbid it, I'm pretty sure. Radiant quartz heaters would be my suggestion.....

We looked at several fairly nice houses before we ended up building, if they did have a register for the garage, they never had return air. You don't want to constantly heat the thing as if it is an inside room anyway, you just want to take the edge off of extreme temperatures. Even if toxic air wasn't an issue, add a return air and actually heat the space as if it is a room and you will lose a ton of money due to heat loss through the concrete floor and drafty overhead doors. There were two houses that did this after converting the garage and back porch into a permanent living space and the heating bills were just ridiculous. One literally racked up nearly $1,400 in heating bills within a month and a half. They emptied two 500 gallon propane tanks plus $200 worth of electricity from a second service that heated the upstairs.


http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/56495/Want-Bad-Air-Put-a-Heating-Cooling-System-in-Your-Attached-Garage

http://www.energyvanguard.com/blog-building-science-HERS-BPI/bid/68883/Are-You-Making-These-Mistakes-with-Your-Garage

Thanks! These links are good info. to know.

obieone

Simple and fast: IF you have a window on the back wall, I'd go with a window heat pump, 12,000 btu's. That way you'll have heat in winter, and cooling in summer.
They usually come with fresh air dampers.

More complicated: Run a supply register to the garage, install a zoning damper that only opens at a certain temperature (58*f) and tie that to an exhaust fan.
If you want it to work for heat AND cooling, you could install a programmable t-stat, with heat setting for 58*f, and cool for 80*f.