The heat is a modest enemy when renovating DIY in the summer. Even if it's indoors, working in a skeleton with the insulation removed or in a non-winded space can quickly raise your body temperature and increase the risk of heat stroke. In this article, we have thoroughly compared portable spot coolers (portable coolers) that can be used as "air conditioning for yourself" in DIY sites in the middle of summer.

I'll also be using the author's experience in actually doing self-renovation, and I'll answer questions from people who say, "Can I use it without a roof?", "Is it OK for home use?", and "I just want something cheap!"

What is the difference between home and commercial use? Which one can be used on DIY sites?

Spot coolers can be broadly divided into "home use" and "commercial use."

• Home use: It also looks smart and is designed for use indoors in a home.
• Commercial use: It is highly durable and designed to be used in harsh environments such as factories and workshops.

It is definitely "commercial" for use in DIY sites. The reasons are as follows:

• It is difficult to stop even in direct sunlight (compatible with ambient temperature of 45°C)
• Metal housing and fully enclosed motor are dust resistant
• It is not easily broken even when operated continuously

However, the prices are high, mainly around 50,000 to 80,000 yen. Therefore, in this article, we will focus on "realistic options that can be used even in the range of 20,000 to 40,000 yen."

Is a cool air fan not allowed? Really cold is "refrigerant"

first,

• A cheap portable air cooler (cooling fan) worth around 10,000 yen

You need to be careful about this. These are "evaporate water and cool the air" methods.

• You cannot lower the room temperature itself
• It can increase humidity and can have the opposite effect during work

A cool fan may seem cool at first glance, but it is difficult to use during humid summer months or during painting.

If you really want to choose a "cold" model, be sure to choose a "refrigerant (compressor type)."

What is cooling capacity (kW)? How many tatami mats should I choose?

It is often seen in spot cooler specifications, such as "cooling capacity: 2.2 kW". This is an indicator that shows how much heat can be removed from the room.

• 2.2 kW → 6 tatami mats
• 2.5 kW → 8 tatami mats
• 2.8 kW → 10 tatami mats

That's the guideline (assuming good insulation).

However, at DIY sites, insulation is peeled off and windows are left open, so in reality, you need to get an output of one rank higher.

Even in a 6 tatami mat space, it is safer to have a capacity of around 2.5 to 2.8 kW. Conversely, if the roof is not covered, the basic principle is "spot cooling" which directly blows air onto people.

You can buy it for around 20,000 yen! 5 recommended spot coolers for DIY

Nichido Kangeki-kun 2 (YNC-B160)

• Cooling capacity: 2.2 kW
• Weight: 26 kg
• Actual selling price: Approximately 24,000 yen
• Features: "A classic commercial spot cooler." The metal body makes it highly durable and moves smoothly.

A "fast model" for DIY renovations. Although it is the cheapest class, it comes with a fully enclosed motor and heat exhaust duct, and has sufficient specifications.

This may be a good option for small spaces or for individuals to prepare one for each individual's individual needs. Working in a hut might be good.

Yamazen YECLD03C

• Cooling capacity: 2.3 kW
• Weight: 26 kg
• Actual selling price: Approximately 26,000 yen
• Features: It has relatively high quietness and excellent dehumidification performance.

The impression is located exactly halfway between home and commercial use. Recommended for those who are also considering daily use.

Iris Ohyama IPP-2225U

• Cooling capacity: 2.2 kW
• Actual selling price: Approximately 37,000 yen
• Features: It has a touch panel and timer function, making it easy to use. The dehumidification performance is also sufficient at 25L/day.

The appeal of this product is that it can be used as a "room cooler" even after renovation. There are also plenty of panels for terrace windows.

Muji Non-brand 2.2 kW model

• Cooling capacity: 2.2 kW
• Actual selling price: Approximately 29,000 yen

The specs are free of problems and have the ability to "cold" performance. However, due to variations in accessories and support, please check the reviews and seller.

---

If you are wondering, "How much can I do DIY myself?"This guidePlease see.

Click here to learn more about the process and installation procedures for each process. Self-renovation Advanced Guide

---

Can spot coolers be used on sites with no roof?

In your home or vacant house under renovation,The ceiling is peeled off and there is no roofSometimes you need to work in a state. In such an environment, is it really okay to use a home spot cooler?

To put it simply, it can be used for a short period of time and after taking measures. However, due to the following risks, advance protection, heat insulation, waterproofing, and filtering are essential.

Possible risks

• "Direct sunlight": The unit becomes hot, causing lower cooling efficiency/The safety device is activated and stopped
• "Dust": Dust during construction can enter the filter or internal motor, causing performance degradation and malfunction.
• "Rain/Moisture": Since it is not waterproof, there is a risk of electric shock or short circuit if it gets wet in the rain while the power is turned on.

In particular, household grades (such as Chestnut Gen, Iris Ohyama) are often made with the environment temperature up to 35°C, so care must be taken when using on extremely hot days or in unsealed structures.

---

Three points to ensure safe use even on roofless sites

1. Sun protection: "Cover with blue tarp + insulation"

To avoid direct sunlight,Stitch simple tarp or blue tarp with stepladders or woodThe basics are: Furthermore, if you apply an aluminum insulation sheet (about 1,000 yen on Amazon or at a home improvement store) inside it, you can expect to reduce radiation heat.

There are air intakes on the top and back of the spot cooler body, so "overcovering" is not allowed. at leastAir passages of over 15cmLet's secure it.

2. Rain protection: "Hisashi" + "Waterproof tarp"

To prevent sudden evening showers,Embed a simple roof (OSB board + square timber)We also recommend this. Protect the connections of drain hoses and extension cords with vinyl to prevent electric shock and leakage.

If you're really worried about this, you can also use the **transfer method of discharging heat indoors (reverse installation).**.

3. Dust prevention: "Add an external filter"

In a place where wood scraps and insulation powders flutter,Performance degradation due to clogging of filtershappens often.

Therefore, the intake grill is used.How to attach a range hood filter (available at 100 yen stores) with Velcrois effective. After the work is finished, vacuum cleaner to absorb dust and replace it the next day to maintain cooling performance.

---

How to buy cheaply second hand or outlet items and things to be aware of

"Even a brand new one is probably over 30,000 yen... I want to make it even cheaper!"
For those people, we also recommend the option of second-hand or outlet items.

Recommended purchase locations

• Mercari/Rakuma: Many individuals list, making it easy to negotiate prices
• Hard Off Second Street: The peace of mind you can see the actual product in the store
• Amazon Outlet/Rakuten Used Items: Manufacturer's warranty also offers a targeted Refrubikable item

Checklist to check second hand

Check items	reason
New year of manufacture (within 3 years)	Reduces compressor life and risk of refrigerant leakage
Comes with a heat exhaust duct	Additional charges of 4,000 to 5,000 yen sold separately
Clean filters and water trays	Check for clogs or mold growth
It is stated if it has been confirmed to work	If you have tested the power supply, you can be more secure

Even if it is second-hand, if it has a 2.2kW cooling capacity, it will be cool enough for a space of 4 to 6 tatami mats.

---

Can a cool air fan or Peltier style be used as a substitute?

Some people may be thinking, "Is it better to use a cooler or a small cooler instead of a spot cooler?"

We have summarized the characteristics of each.

Model	Cooling principle	price	effect	Points to note
Cold air fan	Evaporation heat (water + fan)	5,000 to 15,000 yen	It's cool but the room temperature doesn't drop	湿度が上がるため日本の夏には不利
Peltier type air cooling machine	Electronic cooling device	1〜2万円	Compact but super-slightly cooled	6畳以上では効果なし。局所送風向け
Compressor type (introduced in this article)	Refrigerant circulation	From 25,000 yen	Lower room temperature	Heat duct and drainage are required

In Other Words,"If you want to cool the whole room, compressor type.".
If you want a little better wind than a fan, a cool air fan is enough.

---

Summary of recommended models by use

Purpose of use	Recommended models	Features and estimate price
Authentic, super hot DIY scene	Nakatomi SAC-30	3.0kW / Heat resistant 45℃ / Commercial use strongest (approx. 85,000 yen)
Price-oriented and want to use on-site	Kangeki-kun 2 YNC-B160	2.2kW/Metal housing/26kg (approx. 24,000 yen)
Quiet & for both home use	Iris IPP-2225U	Dehumidification 25L/with remote control (approx. 38,000 yen)
Super budget-oriented	Chestnut Gen 2.3kW model	Responsive to extreme heat, with window panels (approx. 28,000 yen)
It's cool for around 10,000 yen	Cooling fan + ice pack	It's cooler than a fan but the room doesn't get cold

*When posting affiliate links, please place the link in each product name above.

---

Finally: Choose the best air conditioner for DIY renovation sites

DIY and self-renovation have restrictions such as "they can't choose the season" and "the site is harsh",If you incorporate air conditioning skillfully, your work efficiency and physical condition will change dramatically.

There is a high risk of heat stroke, especially in the summer, and it can be dangerous if you overdo it.
To protect the health of yourself, your family and your friends,We recommend that you consider a "on-site cooling system" as soon as possible.

---

How much DIY is it okay to do in the first place? For those who:

Many people are worried, "I would like to introduce a spot cooler, but can I do my own renovations?"

• If you want to know the range of DIY you can do at your own home, Here Check it out!
• If you would like to know the specific steps and construction methods, Here It's packed with useful information too.