Heating/Cooling a Shed
Zone 4a (Maryland), 10’x15’ shed, no windows, ZIP system walls/roof, 3” ccspf walls and 5” in unvented roof. Sits on a slab and there’s no ceiling (open view to roof deck). It’s a tight box.
I want to use the shed for remote office work as well as storage. My concerns are controlling humidity, and keeping the temps comfortable while I am in there, but also be able to keep from extremes at other times (e.g. above 40 in winter & below 85 in summer to protect things inside).
I’ve looked at minisplits, through-wall A/C & heater units, and portable A/C units for combo solutions, and individual piecemeal solutions (a portable A/C, a small heater, and a dehumidifier).
I’m looking for feedback on solutions. Thanks
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Replies
First I would add a window. Working in windowless place is soul crushing.
For such a small, well sealed and insulated place, your best bet is to get one of the fancier inverter window units (ie Midea U shaped one) for cooling and electric baseboards for heat.
For ventilation, you can't beat the cost of a cracked window, but if you want better a Panasonic spot ERV is not too expensive and a simple install. Make sure to get the dual wall cap for it. If you plan the layout well, the wall cap can connect directly to the unit without needing any extra ducting.
Instead of putting the AC unit in the window, I would frame a separate opening and mount it somewhere higher so that it won't be blowing on you directly.
Thanks for the suggestions, Akos. My aversion to windows has to do with my previous shed that was broken into and tools stolen (through a broken window).
I received a $4,500 quote for a 6k BTU Mitsubishi Mini-Split. That's high, but this is a nice shed. Not sure what I'll do yet. I looked at the Panasonic FV-04VE1, but it seems a bit much for a 150' shed.
Jacob,
We heat my wife's 100 sq ft shed with a portable heater. It's a nice shed too, but $4500 buys you a lot of electricity.
If somebody wants to get into your shed, they will. Window or not doesn't matter. Prying open a door is seconds with a good crowbar. If you want to avoid that, don't store any valuables in there.
If you really don't want a window at least install a skylight. If the budget allows get one that can be opened.
If $4500 is not silly to heat/cool the place, I'm not sure why spending $400 on ventilation seems like a lot. In a small well sealed place, the CO2 will spike in no time if you are working in there, decent air quality is worth a couple of dollars.
I have to say that if it's a small tight volume, my first thought is for ventilation. Secondly, I agree with Akos that any type of natural light will vastly improve the feel of the place. Small light tube through the roof? Short transom windows mounted high on a (north or south) wall? Acrylic block?
Consider a Packaged Terminal Air Conditioning PTAC as is found in most hotel rooms. Likely the lowest cost solution.
Note If you want a hard wired AC and electrical outlets in the shed to be code compliant you will need a sub panel in the shed with 36 inches of clear space in front of the panel.
https://www.homedepot.com/p/Ramsond-14-700-BTU-Packaged-Terminal-Air-Conditioning-1-25-Ton-and-Pump-and-Backup-Electrical-Heater-10-6-EER-230-Volt-KCD45-HP/318722646
Walta
Thanks for all the suggestions. I added a window and will purchase the U-shaped Midea to keep the window opening to a minimum. I also added a hole w/PVC pipe for the Midea Cube dehumidifier so it can run continuous and empty to the outside. The shed has CAT6, so I will add Simplisafe motion detectors and window detectors to it.
May also want to look at Gradient Comfort's u-shaped window heat pump unit. Should provide cooling capabilities similar to the Midea but is also a heat pump heater.