EG4 · Single-Zone DIY
~$1,400
EG4 12K Hybrid Solar Mini-Split
Off-grid cabins, garages, and sunny-climate rooms where free daytime cooling justifies dedicating a few panels.
- BTU/h
- 12k
- Volts
- 230
- Refrig.
- R-32
- SEER2
- 22
- HSPF2
- 10.5
- Heats to
- 5°F
EG4 · Single-Zone DIY
EG4 24K Hybrid Solar Mini-Split
EG4 24K Hybrid (SKU 1510986)
~$2,100approximate retailer price at last check, equipment only
- BTU/h
- 24k
- Volts
- 230
- Zones
- 1
- SEER2
- 21
- HSPF2
- —
- Heats to
- 5°F
- Refrig.
- R-32
- Covers
- 1,000 ft²
- Wi-Fi
- Built in
Best forOff-grid cabins, shops and sunny-climate rooms where a dedicated array can power most daytime cooling.
Overview
The 24k is the larger sibling of the EG4 12k hybrid: an R-32 heat pump that can run straight off DC solar panels, off grid AC, or both at once, switching automatically. It accepts up to 2,200 W of panels with no separate inverter, which is roughly five to six 400 W modules. EG4 quotes 21 SEER2 and an HSPF2-5 of 7.9; EG4 publishes no Region IV figure. Heating is rated for outdoor temperatures from 5°F up, so this is a cooling-first unit for a cabin, barn or sunny-climate room, and it does not belong in a cold-climate primary heat role. It sells for about $2,100 at Signature Solar. For off-grid users the draw is running a 2-ton unit on panels without paying for an inverter and battery bank to do it.
- Runs on 90-380 VDC solar or grid AC
- 2,200 W solar input, no inverter
- Pre-vacuumed quick-connect lineset
Cold-weather output
No current listing on NEEP's cold-climate heat pump list (checked October 8, 2026). EG4 rates it to keep running down to 5°F; without a listing there's no certified 5°F capacity figure to check that claim against.
Strengths and catches
Strengths
- +Direct DC solar input up to 2,200 W with automatic switching to 208-240 VAC
- +Pre-vacuumed quick-connect lineset means no vacuum pump
- +Wi-Fi app and IR remote included
- +Cheaper than a battery-plus-inverter setup sized to run a 2-ton unit
Catches
- −Heating operation is rated only from 5°F up, so it is not a cold-climate heat source
- −Only 16.4 ft of lineset ships and extensions are not offered
- −Cannot be paired with EG4 multi-zone systems
- −No Region IV HSPF2 was found; the maker lists 7.9 for Region V
- −Dedicated panels are needed to get the solar benefit; sharing an existing array is awkward
Questions buyers ask
How does the EG4 hybrid solar mini-split work?+
It takes 90-380 VDC from solar panels, up to 2,200 W, and a 208-240 VAC grid feed as backup. Solar covers the load when the sun is up and the grid fills in the rest, so it suits an off-grid cabin or a shop with a small array.
How much of the EG4 install can I do myself?+
The refrigerant side is DIY-friendly: it ships with a 16.4 ft pre-vacuumed quick-connect lineset, rated to 82 ft per the maker's page. Signature Solar says lineset extensions are not offered. You also need a small PV array wired correctly, which is the harder half.
Can it be primary heat in a cold climate?+
The maker's low-ambient floor is 5°F, which is much higher than most cold-climate units, and HSPF2 is not published. It is not NEEP listed, so there is no certified capacity or COP at 5°F. Treat it as a moderate-climate or shoulder-season unit.
Can I add it to an EG4 multi-zone system?+
No. Signature Solar says the unit cannot be used on EG4's multi-zone systems. It works only as a standalone single-zone.
How long is the EG4 warranty?+
EG4 and Signature Solar list a 5-year limited warranty, though one reseller shows 5-year compressor and 3-year parts, so check the listing you buy from. The refrigerant is R-32, an A2L type, but the pre-vacuumed lineset means you never handle it.
How does its price compare with other 24k DIY units?+
At $2,100 it sits near the MRCOOL Easy Pro 24k ($2,109) and below the Perfect Aire Quick Connect 24k ($2,350). Those two are plain grid-powered units with certified cold-weather data. The EG4 earns its place only if you want to run it from solar.
Similar systems
Everything from EG4
Series photoMRCOOL · Single-Zone DIY
~$2,109
MRCOOL Easy Pro 5th Gen 24,000 BTU
A large shop, addition or bonus room in a mild-winter area where a cheap self-install 2-ton is the goal.
- BTU/h
- 24k
- Volts
- 230
- Refrig.
- R-454B
- SEER2
- 18.9
- HSPF2
- 8.7
- Heats to
- -13°F
DiscontinuedMRCOOL · Single-Zone DIY
~$2,200
MRCOOL DIY 4th Gen 18,000 BTU
A master suite, large basement, or small apartment where 12k won't keep up but a multi-zone is overkill.
- BTU/h
- 18k
- Volts
- 230
- Refrig.
- R-410A
- SEER2
- 22.7
- HSPF2
- 9.8
- Heats to
- -13°F