Heating and Cooling planned new shop

[Bob Vavricka]

I am retiring July 1 of this year and plan to start construction of a new shop this spring. It will be approx 1,000 sq. ft. and will be attached to my current small two car garage (shop). I don't have enough space to make it detached and the size I would like.
I plan to spend a lot of time in it so I want to make it so I can work comfortably in it year round. It will be insulated well, I'm just not sure with what yet--thinking closed cell foam if I can afford it. I live in central Oklahoma and I am considering radiant heat in the slab for heating, but wonder if that might be overkill for my location. If I went that way for the heat, what would be the best way to cool it in the summer?
How do you cool and heat your shop and what would you use if you were dong it over?
Thanks for your thoughts.
Bob V.

[Scott T Smith]

Bob, a well insulated 1000 sq ft shop could be managed by a mini-split HVAC system, or a fairly large through the wall unit.

You want an AC unit that will run fairly frequently, so as to keep the humidity level down in the shop. If you oversize the unit, it may keep it cool but the humidity will be higher.

I have radiant heating - nothing beats it for comfort.

Spray foam insulation (either closed cell or open), is definitely your most efficient insulation method.

Scott

[David Hostetler]

The spray foam insulation is great, but pricey... Shop the job around, you may find a good deal from a contractor on that!

Even here in the Houston area, I would do radiant floor heat if I could. Hot air rises, so if the floor is warm, everything is warm... Instead of warm 2' off the ground and up, below that is freezing... I Hate having cold feet!

Agreed on the make sure your AC cycles at least a few times an hour. The humidity needs to get sucked out of the air...

[Bob Vavricka]

Bob, a well insulated 1000 sq ft shop could be managed by a mini-split HVAC system, or a fairly large through the wall unit.

You want an AC unit that will run fairly frequently, so as to keep the humidity level down in the shop. If you oversize the unit, it may keep it cool but the humidity will be higher.

I have radiant heating - nothing beats it for comfort.

Spray foam insulation (either closed cell or open), is definitely your most efficient insulation method.

Scott

Scott, thanks for the reply. What do you use for a heat source for your radiant heating?
Bob V.

[Don Jarvie]

You may want to factor in how long and hot it gets. Radiant heat is a great option for heat but depending on how hot it can get you may need the AC more.

Having a wall or window AC can be noisy and not as efficient as a central AC type AC.

If you put in a wooden floor to insulate it you may want to consider one of the hotel room systems that have heat and AC.

[Robert Parrish]

Bob, I have a 1000 sq ft shop and use a Mr Slim mini-split system and it works great.

[Bob Vavricka]

Bob, I have a 1000 sq ft shop and use a Mr Slim mini-split system and it works great.

Robert,
What size and SEER rating is your unit? I see you are in Florida so are you using just an AC unit or is it a Heat Pump unit? I've never seen one of these in person. Is it very noisy and last but not least does it seem pretty efficient (not expensive to operate). Thanks for posting--the more info I get the better.
Bob V.

[Bob Vavricka]

You may want to factor in how long and hot it gets. Radiant heat is a great option for heat but depending on how hot it can get you may need the AC more.

Having a wall or window AC can be noisy and not as efficient as a central AC type AC.

If you put in a wooden floor to insulate it you may want to consider one of the hotel room systems that have heat and AC.

Don,
I think you are right, it will probably cost me more for the cooling than the heat particularly since I can use natural gas for heating and that is one of the things I am wondering about. If I do the radiant floor, I will still need a seperate system of some kind for the cooling.
I agree that the window units can be pretty noisy. I have what I think is called a PTAC unit in a sun room that is a heat pump we use for heating and cooling. I think it may be over sized for the space because it is hard to regulate the temperature very well although it would probably be better it it had a remote thermostat instead of the controls on the unit.
I wasn't planning on a wooden floor, just an insulated concrete slab with the radiant heat tubes embedded in the slab. Thanks for taking time to reply.
Bob V.

[Ken Garlock]

Hi Bob. I live about 140 miles south of you, as the car drives. My shop is a separate building that is about 600 sqft with a 10 ft ceiling. I use a a 2 ton Trane heat-pump to keep the shop at 60 in the winter and 74 in the summer. However, I must point-out that my 8" SIP walls are R30 and the attic has 10" of Icynene foam insulation. My windows are mounted near the top of the walls on the north and south sides and are non-opening thermo-pane.
The heat pump does have supplementary resistor heat, and it was needed when it got down to 9F a couple weeks ago.

If I were you, I would take my shop plans to a local HVAC contractor and let them size up your system. When we built, I had two separate HVAC bids for comparison purposes.

[Don Jarvie]

Since you can run a gas line look at HVAC units that would be used for your home.

We has a Heat/AC unit put in for our 3rd floor and it was 6000.00 but that included the heater, ac coil and all duct work.

It may seem like a lot of money but if you plan on being in the shop a lot it would be a small investment over time to be comfortable.

[John Davidson]

When I built my shop I went though all the option for HVAC. In the end I decide on a 2 ton heat pump with emergency heat strips for my 800sq ft shop. Some of the thoughts that went into my decision: It’s a hobby shop, I want to be comfortable but I got to be realistic: Since I am not retired my shop will sit idle for days, even weeks between uses: I’ve got 15 to 20 more years before I retire, by then what ever system I choice it will be worn out and in need of replacement: When you consider the amount of use, if I spring for high efficiency how long will it take me to recover the additional cost? And finally how much can I do myself?

With the slow response of radiant floor heat and the extra cost in both the prep for the slab and the need to provide separate cooling this was easy to eliminate. I wanted a system that would respond fast so I could set the temperature low in the winter when the shop was not being used and high in the summer. I wanted to be able to adjust the thermostat to a comfortable setting and be comfortable in 10 to 15 minutes.

I have gas in my house but with the increases in efficiency in heat pumps I would need to opt for a 95% efficiency unit to make it less costly to run a heat pump. That would add cost that would take years to recover when you consider the amount of usage.

I thought a lot about a package unit that is mounted in the wall. This would have been the least expensive option but I just could not come to terms in cutting a hole that big in the side of my shop. Also I wanted good air flow and temperature balance in the shop. I don’t think a single source would have accomplished this. For the same reason I eliminated a mini split system.

In the end I installed a 2 tom heat pump from Goodman that I purchased through a contractor friend. I installed the unit myself including all the duct work. I had another friend that is an HVAC tech inspect my work, braze the lines and adjust the charge on the unit. I paid him $300 to do this. When my total cost was accounted for I had around $2500 in everything. The unit heats and cools the shop quickly with the thermostat set to 50 degrees in the winter and the unit off in the summer. I average about $25 a month on my power bill.

[Bob Vavricka]

Hi Bob. I live about 140 miles south of you, as the car drives. My shop is a separate building that is about 600 sqft with a 10 ft ceiling. I use a a 2 ton Trane heat-pump to keep the shop at 60 in the winter and 74 in the summer. However, I must point-out that my 8" SIP walls are R30 and the attic has 10" of Icynene foam insulation. My windows are mounted near the top of the walls on the north and south sides and are non-opening thermo-pane.
The heat pump does have supplementary resistor heat, and it was needed when it got down to 9F a couple weeks ago.

If I were you, I would take my shop plans to a local HVAC contractor and let them size up your system. When we built, I had two separate HVAC bids for comparison purposes.

Ken, Thanks for taking time to reply. I plan to insulate my addition pretty good--still checking into options and cost, but I think spending some extra money for insulation will pay for itself pretty quickly. I have done some looking a SIPs, who did you get yours from? Is your roof SIPs as well? It doesn't sound like it if you used foam in the attic. Did you foam the underside of the roof deck? I have considered doing that. I am also planning on 10' walls with windows high on the wall to leave the wall space open. I will get a HVAC contractor to size up the system once I decide what I am going to do. If I go with radiant heat, I plan to do most if not all the installation myself with design help from one of the online radiant heat sites.
Bob V.

[Bob Vavricka]

When I built my shop I went though all the option for HVAC. In the end I decide on a 2 ton heat pump with emergency heat strips for my 800sq ft shop. Some of the thoughts that went into my decision: It’s a hobby shop, I want to be comfortable but I got to be realistic: Since I am not retired my shop will sit idle for days, even weeks between uses: I’ve got 15 to 20 more years before I retire, by then what ever system I choice it will be worn out and in need of replacement: When you consider the amount of use, if I spring for high efficiency how long will it take me to recover the additional cost? And finally how much can I do myself?

Good points, I will be retiring in July and plan to spend quite a bit of my time in my shop, so I will probably be the one worn out in the next 15 to 20 years. I don't see energy costs getting any cheaper so I'm willing to spend some extra now. How much I can do myself is also a consideration.

With the slow response of radiant floor heat and the extra cost in both the prep for the slab and the need to provide separate cooling this was easy to eliminate. I wanted a system that would respond fast so I could set the temperature low in the winter when the shop was not being used and high in the summer. I wanted to be able to adjust the thermostat to a comfortable setting and be comfortable in 10 to 15 minutes.

The need for some kind of separate cooling is probably my only hesitation on the radiant floor. I would plan to do installation of the radiant heat. Either way, from what I can read, the slab needs to be insulated so the materials would be the only extra cost.

I have gas in my house but with the increases in efficiency in heat pumps I would need to opt for a 95% efficiency unit to make it less costly to run a heat pump. That would add cost that would take years to recover when you consider the amount of usage.

Sounds worth looking at.

I thought a lot about a package unit that is mounted in the wall. This would have been the least expensive option but I just could not come to terms in cutting a hole that big in the side of my shop. Also I wanted good air flow and temperature balance in the shop. I don’t think a single source would have accomplished this. For the same reason I eliminated a mini split system.

In the end I installed a 2 tom heat pump from Goodman that I purchased through a contractor friend. I installed the unit myself including all the duct work. I had another friend that is an HVAC tech inspect my work, braze the lines and adjust the charge on the unit. I paid him $300 to do this. When my total cost was accounted for I had around $2500 in everything. The unit heats and cools the shop quickly with the thermostat set to 50 degrees in the winter and the unit off in the summer. I average about $25 a month on my power bill.

Again thanks for taking time to make a detailed reply. I appreciate it and it gives me more to consider when making my decision.
Bob V.

[Eric Gustafson]

My shop is only ~700 sq ft. I put in a 2 ton Mr slim heat pump. It required putting a 3" hole in my block wall surrounding the shop. My shop is insulated well, but I have only used the heat so far. I live in the SW and the winters are mild. The heat works excellent. The mini spilt is a little oversized for the space, but the invertor function allows it to "throttle down." It is very quiet.

I talked to several contractors who agreed I needed the higher tonnage to compensate for the heat generated from my dust collector and tools when summertime comes.

[Greg Portland]

I'm in a 25x40 and use radiant heat in my slab. I use a gas fired water heater to drive the system. I'm in Oregon so cooling just requires an open door and a fan.