Rant about Home Depot

[neanderman]

I'm planning a shop as part of a new garage. I'm planning on an electric heat pump to keep the temperature within a range and keep the humidity manageable. I have an older wood burning stove that I figure to use for cold days.

I have natural gas I the house, but I'm not sure I want to go to the expense of running a gas line and buying a furnace. I'd certainly accept any input. I plan to use 6" outside walls and as much ceiling insulation as possible. The shop side will be one bay of a two bay garage. It will not have an overhead door, but will instead have a door open to the other bay for moving things in and out.

[curtis cutter]

I'm planning a shop as part of a new garage. I'm planning on an electric heat pump to keep the temperature within a range and keep the humidity manageable. I have an older wood burning stove that I figure to use for cold days.

I have natural gas I the house, but I'm not sure I want to go to the expense of running a gas line and buying a furnace. I'd certainly accept any input. I plan to use 6" outside walls and as much ceiling insulation as possible. The shop side will be one bay of a two bay garage. It will not have an overhead door, but will instead have a door open to the other bay for moving things in and out.

Sounds like you are using the same construction techniques as I did with 2x6 walls and R-38 in the ceiling. I particularly sealed all openings from the inside. Before I insulated the walls I caulked the top plate exterior wall to stop convected air loss. I also applied caulking to the top plate prior to putting up the sheetrock at the ceiling level. I also sealed each electrical ceiling box where wires enter.

Basically, I wanted no air to leave the inside envelope outside of my use of fans to mechanically do it.

[neanderman]

Thanks, Gregg. Yes, R-38 in the ceiling. I'll be finishing the inside walls with OSB rather than sheetrock, since I think it's a little more resistant to 'bumps.' I used it in the basement wood shop and it's worked out well.

Good tip on the caulk, and I wouldn't have thought about the electrical boxes.

[Harold_V]

It costs me quite a bit to heat everything, but I am not willing to live with the cold. I'm not all that fond of running my machines in the first place, so not being reasonably comfortable really ruins it for me. I do not keep my shop on the warm side, as the thermostat is set for about 63°, but the machines (and I) benefit from the more stable temperature, and it's not miserable to go to the shop when it's been cold.

I'd suggest you make provisions for adding a furnace in the shop. It could be small, as you'd only be heating a small area, so it wouldn't be all that expensive to heat. It's a lot nicer to enter a shop that hasn't chilled, and it's a lot better for the machinery, too (they don't condense moisture if you keep them warm). Of course, if you don't spend a lot of time there, maybe it wouldn't be necessary. A lot depends on how much time you anticipate spending in the shop, and how cold it gets where you live. Some folks simply put the shop on the back burner when temps swing out of the comfort zone (either hot or cold). That wouldn't be an option for me.

H

[liveaboard]

Because I heat with a hydronic system, an outdoor boiler is considerably more complicated. For one, it's a closed system, which I have yet to find being made commercially. In order for this type of system to operate without issues, it must remain closed. That would mean a heat exchanger would be required, or the auxiliary boiler would have to be built accordingly.
H

I found a whole website devoted to this subject; in the US and Europe, you can buy high efficiency units with closed loop circulation.
https://www.hearth.com/talk/forums/the- ... rnaces.13/
There are links on that site to plans for home building as well as discussion about different factory built units, US and European.

A team from the University of Maine designed and made the plans public in 1979, and that work is still considered definitive.
I have the plans in PDF if anyone wants them. You need to cast the ceramic fire chamber, or build from firebrick. The plumbing and steel work will be easy for any of us.

The factory built ones work about the same as the 1979 plan, but come in a neat enameled metal enclosure. They cost around $5,000 last time I looked.

Generally, they burn at around 800C inside, and 20kw. The flue gas is so cool after the heat exchanger, it has to be drawn by a fan. The burn chamber is closed, it does a complete burn to ash before you open it. There has to be a heat sink capable of absorbing the energy, or there will be trouble.

The high burn temperature makes it possible to burn pine [or any other wood] without soot buildup. Obviously, different woods result in different heat yields.
They don't have to be outside, depending on your local building codes and insurance. An attached shed would probably do.

The difficulty with the closed loop for these high efficiency high output systems is you need a large heat buffer, a big pressurized water tank. The pressure isn't very high but you need a lot of insulation so it's a whole project of its own.
Many people use a scrap bulk propane tank.

Such tanks are available factory made, but as the production is low volume they're expensive, and due to size shipping is expensive too.
This sort of elaborate setup is probably only worthwhile if you use it to heat your home as well as your shop.

Here's my work on stratified heat storage; http://aljezurfarm.com/Stratified%20hea ... eating.htm

[RMinMN]

Thanks, Gregg. Yes, R-38 in the ceiling. I'll be finishing the inside walls with OSB rather than sheetrock, since I think it's a little more resistant to 'bumps.' I used it in the basement wood shop and it's worked out well.

Good tip on the caulk, and I wouldn't have thought about the electrical boxes.

Use the sheetrock and cover it with something that will be resistant to bumps. If you ever have a fire get started in that portion the sheetrock will help contain it there and the rest of the structure may be able to be saved or at least give you time to get things out of the part not involved in the fire. OSB is the wrong wall covering.

[tornitore45]

I just installed this summer a Mitsubishi 1.5 tons mini split system in a 3 bay garage. Is AC/HeatPump
Have not used the Heat Pump yet but I am very pleased with the AC performance.

[curtis cutter]

Thanks, Gregg. Yes, R-38 in the ceiling. I'll be finishing the inside walls with OSB rather than sheetrock, since I think it's a little more resistant to 'bumps.' I used it in the basement wood shop and it's worked out well.

Good tip on the caulk, and I wouldn't have thought about the electrical boxes.

Use the sheetrock and cover it with something that will be resistant to bumps. If you ever have a fire get started in that portion the sheetrock will help contain it there and the rest of the structure may be able to be saved or at least give you time to get things out of the part not involved in the fire. OSB is the wrong wall covering.

Thinking along the lines of fire, if you are going to plumb a shop with water be sure to put a garden hose connection in an interior wall so that you have that readily available should a fire start. Being in the "fire business", I have found that most shop fires are wither started amidst debris in the shop or fed by debris in the shop. Welding is a particular hazard as a spark can start a small fire that goes unnoticed when the lights go out and one goes back to the house or can build into larger flames while the welding hood is down.

Shops with good "housekeeping" habits and attitudes have fewer fires but that could be due to a lot of factors. Those shops tend to look at fires as real threats and have that in their mindset even during construction. I now regret that I did not run a 14-3 wire to my shop to tie into my smoke detectors in the house. Bad planning there.

[steamin10]

I am on natural gas, but have sought to augment my heat with an outdoor boiler. Its initial cost is about $5k with the space limits imposed by the county. The furnace must be 50 feet from a structure making the runs for piping less efficient and costly at about $5 a foot for material. Another hook is the insurance companies triple the fire insurance with stoves and heaters here because they can.

I use propane to fire my metal furnaces with 100lb bottles, as my garage has no line to it.

[Harold_V]

I found a whole website devoted to this subject; in the US and Europe, you can buy high efficiency units with closed loop circulation.
https://www.hearth.com/talk/forums/the- ... rnaces.13/
There are links on that site to plans for home building as well as discussion about different factory built units, US and European.

Thanks for the link! I was never successful in any of my searches, so it is very welcome. That's especially true of today, as I noticed a 10¢ increase in the price of offroad diesel, which is what I've been buying for heating. The price increase is only for one location, putting their price at $3.29/gallon. I managed to purchase 56 gallons for $2.99/gallon.

If I was just a few years younger!

H

[liveaboard]

Cheer up, over here we pay $5.20; but that's only supposed to be used in the tractor.
For road or any other use [heat, generator, anything] diesel costs $6.60 per US gallon.

Other fossil fuels are similarly priced, pellets are cheaper, firewood cheaper still, and solar home heating is what I'd like to do.

[Harold_V]

Terrible price you pay, for sure.
I can still remember when diesel, here, was only 18¢/gallon. (Did I mention I'm quite old?)
The first year we put our heating system in use, we paid 72¢/gallon for #2 heating oil (same as off road diesel). That was way back in 1999 as I recall. Things got a lot worse here, although we've never had to pay what you folks do. I expect that is going to change, however. I'm trying to keep a good thought.

H