Tiny House HVAC

tiny house hvac

I recently wrote an article on the best tiny house heaters. I noticed that many visitors landed on that page while searching for tiny house HVAC. HVAC stands for heating, ventilation, and air conditioning. Mini splits and window units are two main ways people usually heat and cool a tiny house.

 

Mini Splits

Mini splits are my favorite way to heat and cool a tiny house. They are less obtrusive than window units, while being more energy efficient to operate. Since they are ductless, installation is easier and efficiency is increased. Ducting can account for up to 30% energy loss with a central unit. This is a point of contention since some people say proper ducting would not have loss. That same guy also claims a central a/c unit would cost 1/3 the cost of a mini split to operate for a 2000 square foot house. Fortunately, we aren’t interested in such a large space.

The zone nature of mini splits makes it easy to only heat or cool the area of the house being used. The biggest downsides of mini splits are a high initial cost and the fact you are supposed to have a certified HVAC technician do the installation. With a mini split system, you are likely to spend at least $600. Window units with heat can be found on sale for less than $200. If your budget is tight, that might be the main deciding factor for you.

Pros

Energy efficient (SEER 13 to low 20s)

Less obnoxious looking than window units. The outdoor unit can be located up to fifty feet away from the indoor evaporator, increasing the ability to locate in an inconspicuous location. You typically only need a 3 inch hole in the wall to connect the indoor and outdoor components.

Up to 4 zones with unique thermostats. This factor isn’t critical to most tiny houses, but it is still need an adds to the overall efficiency of operation. Many tiny houses would benefit from at least a dual zone system.

Cons

– Installation requires an HVAC technician. Even if you have the electrical know how, you are supposed to have a refrigerant license if the unit does not come pre-charged. Having to hire other people can be one of the biggest costs in realizing your tiny house dreams. The best advice here is to shop around if you need someone to help. Some techs won’t want to install equipment you bought online, while others will be fine with it. They might give you grief about warranty issues, but that shouldn’t be a big factor as long as you bought a good unit in the first place.

The initial cost is higher than a window unit.

Recommended Mini Split Systems

1. Pioneer 12,000 BTU – the cost is right at $700 shipped. The reviews are also outstanding. Amazon marks this unit as the number 1 best seller for single room mini splits. This unit boasts a 17.5 SEER rating. This is certainly better than a window unit, but more efficient mini splits exists. That said, this is one of the best reviewed mini splits on all of Amazon.

pioneer 12000 btu mini split

 

2. Klimaire 12,000 BTU – this unit costs about $150 more than the Pioneer. It is slightly less efficient at 16 SEER. Inverter technology allows for heating in temperatures down to 5 degrees Fahrenheit. While that isn’t a big selling point to me in Texas, I know many of you live in much colder climates.

klimaire mini split

3. LG 12,000 BTU LS120HSV5 – this unit is expensive at right around $1,500. The plus side is a whopping 22.7 SEER along with the renowned quality of the LG brand. It is a lot of money no doubt, but you are likely to be happy with this purchase for years.

lg 12000 btu mini split

 

Window Units

Window and through the wall units are cheap, reliable, and easy to install. Any slightly handy person can install a window unit without too much grief. All you need is a buddy to help since they tend to weigh too much for one person to handle well. You always want to make sure you find a unit with the right amount of BTU’s for your space. This is not a purchase where more is always better. More is frequently just far less efficient. Always check whether you are looking at a 115 or 230 volt unit. You do not want to have to pay to ship back a 90 pound plus window unit and be stuck in the heat or cold for another week or two.

Pros

Cheap. Good units can be purchased for just a couple hundred dollars.

Easy to install

Cons

Not energy efficient. Window units are a damn site better than a portable a/c or heater, but they are not good when compared to mini splits or central air.

– They look trashy. I fully realize this is a subjective claim. I mean several million dollar apartments in Manhattan frequently have window / through the wall units. I still think they look like ass (not the pretty ones).

Loud. Window units are getting better and some are downright quiet compared to other units. You are still likely to clearly hear when these units operate. It is kind of like living next to a train. You are likely to not hear it after a little while or be driven completely mad.

Security Vulnerability. You can secure a window unit well enough that no one is going to kick it out without some extreme effort, but most are not installed that well. It is not uncommon to see stories where robbers gained access to the domicile by pushing out the window unit.

Recommended Window Units

1. FRIGIDAIRE FFRA1222U1 12,000 BTU cool with 11,000 BTU heat – This is at a mid level price point at around $330 shipped. It will get the job down though. When it comes to window units, I personally would only buy Frigidaire, LG, or Frigidaire. The FFRA1222U1 is made for areas up to 550 square feet.

frigidaire window unit with heat

2. Friedrich Chill Premiere with 8,000 BTU’s cool and 3,500 heat. You can purchase this model for less than $400. Friedrich is a highly respected name in window air, so you shouldn’t worry about the quality.

friedrich window unit

Avoid Portable A/C Units

My final note is to avoid portable a/c heater units like the plague. They are incredibly inefficient. They can be a tempting option because of how easy they are to operate and cost, but don’t do it. You deserve better.

11 thoughts on “Tiny House HVAC

  1. First off, thank you for all the information about the ductless/mini split units in tiny houses. I have a 335 sq ft tiny home in Savannah, Ga and a fully functioning HVAC unit is absolutely crucial. That being said, I must adamantly disagree with your suggestion to go with the Frigidaire unit (or, honestly, Frigidaire anything at this point). I have that exact unit and even with proper installation (I had it installed professionally) within 13 months of ownership it is completely covered in black mold. I’ve been fighting with them to take at least partial responsibility for the unit’s malfunction and design flaw but even with a 5 year warranty, they refuse to help. Also, if that doesn’t dissuade you from purchasing that particular unit, this might. Frigidaire will not service any unit under 12,001 BTU no matter how new. Don’t waste your money like I did.

    • Do you have duct work and everything? I have a 364 sq ft tiny house and was just kinda wondering on the cost

  2. This is some great information, and I appreciate your point that split air conditioning systems are good for small houses. My husband and I are going to be moving into our first house, and it’s pretty small. We want a good cooling system, so we’ll definitely look into getting a split air conditioner. Thanks for the great post!

  3. Can you address off-grid tiny homes? I can’t imagine that losing 50% to convert energy to an AC application for active cooling or heating can be the best way to go?

  4. I know it’s been over a year since you wrote this and some things may have changed as far as your top three, but do you think it would be beneficial to have more than one air return in a tiny house? Building on a 28ft gooseneck and sleeping quarters are on opposite ends of the house. Floor plan is open but the boys of my house are pretty picky about being too hot or too cold.

  5. Any suggestions are mini split air/heat units. I’m trying to decide between a 115v and a 230v. Any suggestions? Thanks.

  6. Can someone help us? We built a mobile office so its a hybrid tiny house and trailer. installed AC with heat pump. We are in Denver. We need help upgrading our system

  7. To add a few additional points:
    – Window ACs get louder as they age. When I got my Keystone, it was surprisingly quiet, but after 5 years of moderate use, it’s vibrating the walls. The extra noise just tells you to have a new unit on standby to replace it.
    – Window ACs are only designed to live about 5 years. Then you throw them out and buy new. This isn’t as bad as it sounds though. For the cost of that Frigidaire up there, you could afford to buy 5 window units. That’s enough window units to last you 25 years and if you’re honest, you’re not going to be in your tiny home that long. The long-term cost advantage, then, goes to window units.
    – Wall ACs last much longer, especially if you get one of the commercial-grade ACs used in hotels, from a company like Friederich. If you don’t want to replace window units regularly, get a wall unit. You’ll have to cut a reasonably sized hole in your wall, but only once. The mini split also requires a hole in the wall (admittedly much smaller) and you still have to make some kind of platform outside for the condenser unit and find a clean way to run lines down your outside wall. You also have to hire an HVAC technician AND an electrician to connect it up. On the whole, a wall unit is much cheaper to install.
    – Wall units are easy to swap out. Though hole sizes aren’t entirely uniform, it’s usually not terribly hard to find another wall unit to fit in your existing opening should the first unit need replacing. This can usually be done by removing a few screws and sliding it out. What’s involved in replacing your mini split components?
    – Window and wall units are vastly easier to install. These systems are all-inclusive, turnkey solutions. A window unit is ONE box, with every working component inside. In most cases, they have ONE cord that plugs into an ordinary wall outlet. A mini split comes with two big boxes, bare wires and a two refrigerant lines. They take up more space than a window unit and require specialized installation, including HVAC and electrical. Put another way, the installation instructions for a window AC are 9 pages long. For a mini split, they are 27.
    – Mini splits aren’t any prettier than window units. You still have a giant, ugly compressor/condenser unit that has to go somewhere. In most tiny house applications, that condenser unit is going to sit perched right on the same trailer as your lovely home. You still have giant, ugly refrigerant lines going up your exterior wall. You’re going to have to cover those up somehow, or learn to like the aesthetic. You are likely to have excess line that you’ll have to stash somewhere, probably in a big coil next to the condenser.
    – Most of the “efficiency” of mini splits is illusory. The supposed inefficiency of window units has mostly to do with poor installation. If you air seal around the unit properly, you’re never going to justify the additional cost of a mini split with real-world power bill savings.
    – Avoid anything from Frigidaire, or GE. Those companies build garbage. Save yourself the exasperation.
    – Finally to the commenter above, “off-grid” and “AC” are mutually exclusive. You can’t have both. AC simply requires too much power. You can’t put enough solar panels on your property to power even the smallest AC. Sorry.

  8. I need a heat and cool unit that will work in very cold winters that reach -12 at times.I only wanted to install one source in a 394 sq ft house,

  9. Don’t ever buy climateRight air /heat unit-ANYTHING. This is the worst China made junk on the market. The sales pitch makes it seem great- the reality is, it is not made to last past a crappie warranty. They had to send me 2 different units as the first one completely quit working in 3 months and that one fell inside the year before it fell apart. Second unit lasted 13 months and the plastic fan blade parts on the inside deteriorated and fell apart. Horrible product! DON’T BUY ClimateRight- waste of your money.

  10. For a minisplit, do you recommend installing the outside compressor on the loft end (tongue side, the “back” of the house), or is that noisy in the sleeping area? Or, would it be a mistake to install on the “front” under the bay windows?

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