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Community and Q&A

Ductless minisplit for a storefront?

jonathanforddalton | Posted in Mechanicals on

I’ve been reading a lot about minisplits on here and their virtues for heating and cooling homes. I currently rent a 500 square foot storefront on the ground level of a 3 storey brick commercial building. The climate zone is 5B. The only heat is electric baseboard plus a space heater in the back workshop area. This winter I was paying $300 per month to heat the small space and with the heaters full out, it was still 15 degrees (celsius) in here. This is despite the two side walls being cojoined to adjacent buildings and the space is only 12′ wide, so the front and rear walls are very small.

I realize the building is old and leaky and that heat escapes every time someone comes in the door. If I can achieve at least mediocre air sealing (right now it’s probably awful), would a 9000 or 12000 BTU minisplit unit heat the space? I’m sure someone has tried it in a storefront like this, as there are thousands just like it. I’m trying to determine if I should ask the landlord to consider this option and possibly contribute some money and/or labour to it myself.

Thanks for any advice

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  1. mackstann | | #1

    A small pizza place near me has two mini splits in their dining area. Just imagine the heat from that pizza oven in summer time.

    Mini splits should work just fine, but to size them you should really have a load calculation done. Preferably by an energy rater who does commercial work and knows how to account for something like a door that opens frequently.

  2. wjrobinson | | #2

    Every foot of electric baseboard for residential use anyway = 3412btu/4 = 853 btu/foot. You could also figure out from your $300/month cost say divide by cost of a KWH then divide by 720 hours/month and multiply by 3412btu/KW to see what your present btu needs per hour is.

  3. wjrobinson | | #3

    Interesting factoid to me anyway. In my area there are recently many mini splits being installed. And my pizza place has had splits for years. BUT and this is a big but, ALL the installs are for AC only. And my main HVAC supply house when asked about heat use looked at me in shock. The thought of heat with a mini was like mentioning using crack to get a job done faster. Nuts. LOL.

    So there must be a huge market to jump into if someone wanted to be the mini split guy for heat and cooling not just cooling.

  4. jonathanforddalton | | #4

    I'm sure it would work great for cooling - there's a `~20,000BTU air conditioner above the door which barely has to run even on the hottest days. It's the heating that's the issue here.

    What I don't understand is the derating curve for extreme high and low temperatures. According to the primer on minisplits on this site, the inverter units can run at 100% efficiency as low as 5°F. So a 12,000BTU unit will put out 12,000BTU of heat at outdoor temperatures down to 5°. Are there derating curves available for temperatures below that?

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