MRCool launches do-it-yourself monoblock heat pump without outdoor unit

MRCool has released a new heat pump that skips the outdoor unit altogether. Normally, ductless mini-split heat pumps (systems with an indoor unit connected to an outdoor condenser by refrigerant lines) need that outside component. This new "monoblock" version packs everything into one wall-mounted box, so there's no condenser to place outside and no refrigerant lines to run between indoors and out.

The unit plugs into a standard 115-volt outlet, the kind already in most homes, so it likely won't require an electrical panel upgrade or special wiring. It's sized for smaller spaces — garages, home offices, accessory dwelling units, studios — with a cooling capacity of 10,000 Btu/h and heating capacity of 9,000 Btu/h (a little under 1 ton of cooling power). MRCool rates its efficiency at SEER2 15, EER2 9.9, and HSPF2 7.5, and says it runs at 32 to 46 decibels depending on speed.

Like MRCool's existing mini-splits, this one is built for do-it-yourself installation, since the refrigerant components are sealed at the factory and there's no refrigerant to handle on-site. That means no licensed HVAC technician or vacuum pump is needed for setup. You'd still need to cut the required wall opening and follow local building and electrical codes, so some basic construction work is still involved. For homeowners with a small space that's hard to heat or cool — one where running ductwork or installing an outdoor condenser isn't practical — this offers another option, particularly for replacing a space heater or window unit with something more efficient.