Would This Be Enough Heat?

[Matt M PA]

I'm starting to get excited...the foundation was poured this week, and the structure itself is to be erected this coming Wednesday and Thursday.

It's a 26x32 with three insulated doors, and 8 insulated windows. The attic above two of the bays will have a staircase, the other bay with have a cathedral ceiling for a lift. I was hoping to have spray-in insulation, but don;t think I can swing the cost of that with everything else going one...and I'll put batts in the 2x4 walls, and of course in the ceiling.

I have considered a Big Max propane unit, but am concerned about how often the tanks will be drained, etc. (I'd like to keep it at 50 or so...and run it up when I work out there)

In my current attached garage I have a Dayton G73, 17,000BTU that works great. It's a much smaller space though.

A friend has suggested a pair of these G73s as opposed to propane. another friend suggests an electric heat pump...but again cost may be against me.

Your thoughts are appreciated!

 

[Dragster Racer]

With only 4" in the walls, I think you will struggle to kick up the heat on cold days when you want to work out there. I do think that 50 degrees would be doable, but recovery would be poor. I think a pair would just barely do the trick myself, but they may do better than I think.

 

[GSSFC]

Buy some rigid foam board, use that first and can foam the seams. Then add your fiberglass, should help dramatically.

Tim

 

[hammlm]

Matt M. from SE PA, eh?

I'm also Matt M. from SE PA! Where do you hail from?

Two winters ago, I got a bonus 27x45 garage when I put an addition on the house. Slightly different, but at least in the climatic sense, we're in the same church.

I did 2x6 walls with bats. There is living space above, so that helps greatly. Approximately 2/3's of one wall is common to the house. I was pretty **** about insulating / caulking, etc. I have 2 9-foot garage doors (I can't remember the R-value of them, but I sort of think that's a bunch of hooey anyway on garage doors), and 2 man-doors, and three windows. I didn't know what to do for heat, so I just got online at Northern and ordered the 75K BTU Bigg Maxx. I'm running propane, not NG.

In the end, I definitely could have went with the 45K. Once I get the slab, cars and my tools up to my constant temp (I keep it at 59) it barely has to run. On the coldest nights last winter, it would run 4 or 5 times overnight, for about 10-minutes each time. I think it ran only a handful of times last week when we had our little cold snap.

On a saturday morning, I can go out there, and kick the stat up and by the time I pour a cup of coffee, and get my shoes on, it's downright hot out there.

It's not whisper quiet by any means, but I can have a conversation, talk on the phone or whatever when it's running without a problem.

Interested in hearing where you are.

 

[Matt M PA]

Thanks for all the info!

We had originally planned for spray in insulation, so 2x4 walls would have been fine. But...after hearing the real cost of this...I have to abandon the spray insulation. (Apparently those that suggested this were not informed)

Since this is detached...I really need to make sure that it can stand on it's own with heat.

hammlm...I am near Newtown, PA. I also wonder what size propane tank you have as well as how often you need to refill.

I have no problem with either propane or electric...but do have concerns about when the PECO rate caps end.

Finally, I can say that in my little 18x18 the G73 works great...but it's much smaller with 7 foot ceilings...I too have concerns that these G73s are not up to the task.

 

[hammlm]

I'm out in the western part of Chester County, but one of our offices is in Newtown.

I have a 500 gallon tank. It was filled for the first time in February of 2007. I haven't had to re-fill it yet, and it's about 30% remaining. It also provides fuel for backup heaters in two electric heat-pumps that condition my living space. I was fairly picky about how the house and the garage was insulated, and I guess that is paying off. The structure is wrapped in Tyvek; I did cellulose in the living spaces (2x6 walls) and bats in the garage (also 2x6). I caulked and sprayfoamed everything pretty tightly before I put the bats in. Yesterday, I was working on painting the garage walls, and got it from 60-82 degrees in there in about 10 minutes. Then I had to crack the doors and open the windows......

 

[carguykeith]

You know you really don't loose that much heat through your walls, just make sure you keep infiltration to a minimum and insulate the hell out of your ceiling (R38 min and R50 if you can swing it). Also I assume your foundation is insulated? If so 34kbtu should be plenty if that's the actual output, if it's input and they are say 80% efficient than you could definitely have some isssues with recovery time as it would only be 27kbtu. Still doable but plan on waiting for temps to come up when you bump the t-stat...

 

[Matt M PA]

Thanks guys!

I think, yesterday...it was solved. An HVAC Tech friend asid he found a deal on a 3 ton electric furnace with an indoor coil. It'll cost about $700 to put in. It's somewhere around 45,000 btu. Later, we can add the ouside heat pump and A/C if needed. But, this will get me over the hump.

I was concerned about running without the heat pump, but we figure that the heat pump would not function under about 30 anyhow...so with winter coming, we won;t see a huge incresae in cost to operate.

I can also mount this beside the attic floor, in the attic, so I'll lose no floor space.