Mini-Split Cleaning Between Tenants

If you own long-term rentals in New Hampshire and the units have mini-splits, the turnover is when to clean them. Not spring, not when a tenant complains — the vacancy. The incoming tenant starts with a unit that does not smell, which heads off the one maintenance argument that tends to arrive by text at 9pm in July. Below: what the job involves, what the law lets you push onto the tenant, and what it costs per building.

Why clean a rental mini-split between tenants instead of during the tenancy?

Because the room is empty. A real deep clean means pulling the housing off the indoor mini-split, hanging a bib bag under it, and rinsing the coil and blower wheel with a pump sprayer — 60 to 90 minutes per unit. With a tenant in place you are scheduling access, sliding a dresser aside, and working around their day off.

There is a second reason. Once a tenant puts a complaint in writing, you are working to a deadline: RSA 540:13-d gives a New Hampshire landlord 14 days from written notice to correct a substantial violation of health and safety standards before the tenant gains a defense to an eviction for nonpayment. Most musty mini-splits never rise to that level. But you would rather do this job in an empty apartment in October than fit it into 14 days in August because somebody wrote you a letter.

Is a dirty mini-split tenant damage or reasonable wear and tear?

Wear and tear, in almost every case. A coil fouls because the unit ran, and running it is what the tenant rented. RSA 540-A:7 gives you 30 days to return the deposit with an itemized list of deductions, and missing that can cost you twice the deposit. Deductions cover damage beyond reasonable wear and tear. Dirt is not that.

We say that knowing it costs us the argument for billing it back. There are edges — a bent fin pack, a snapped louver, a line set cut with a string trimmer, an outdoor compressor used as a shelf. Those are damage, and they photograph. A gray coil does not. Put the cleaning in the operating budget next to paint and carpet and stop trying to make the deposit carry it.

Where records earn their keep is the condition report. A dated move-in line — “bedroom mini-split deep cleaned, coil and blower wheel clean, drain flowing” — with a matching note at move-out is how you tell a normal year from a tenancy that wrecked something. Otherwise you are arguing about a photo with no baseline.

What should a NH lease say about mini-split filters?

That the tenant washes the mesh filters monthly and reports any smell, drip, noise, or fault code in writing. Reasonable, cheap, and it genuinely slows fouling. What does not belong in a lease is a clause making the tenant responsible for cleaning the unit, because they cannot do it — the coil and blower wheel are behind the housing.

• Tenant washes and fully dries the mesh filters monthly — same clause as smoke-detector batteries
• Tenant reports smell, dripping, black specks, or a blinking light in writing; you answer in writing
• No aerosol “AC cleaner” sprayed into the unit — it drips onto the control board and glues dust to the coil
• Landlord handles the annual or biennial deep clean and the outdoor compressor, at turnover where possible

The filter clause is not busywork. ENERGY STAR’s maintenance checklist says inspect, clean, or change filters monthly, and warns a dirty filter raises energy costs and can damage equipment into early failure. On the part the tenant cannot do, the same checklist is blunt: dirty coils cut cooling and make the system run longer. The DIY vs. professional guide draws that line.

Does a musty mini-split make a NH rental uninhabitable?

By itself, almost certainly not, and we would rather say so than sell a panic. New Hampshire has no state mold statute. The tenant’s remedy runs through the implied warranty of habitability and RSA 540:13-d, which requires a substantial violation of health and safety standards that materially affects habitability. A smell on startup rarely clears that bar.

Some New Hampshire towns and cities do carry housing codes that reach further than the state does, so a local inspector is a different conversation. But fix it because it is a two-hour, $199 job, not because someone called it a code violation. The musty smell guide covers what is growing in there.

The honest counterweight on the efficiency argument, too. A 2002 Lawrence Berkeley National Laboratory study by Siegel, Walker and Sherman found typical coils foul enough to double evaporator pressure drop in 7 to 11 years — well inside the 15 to 30 year life expected of the coil — but that the resulting efficiency and capacity losses are usually under 5 percent, worse only in marginal or extreme conditions. Translated: on a mild day a dirty rental unit mostly still works. On the coldest week of February, or a 90-degree afternoon in an upstairs bedroom, airflow gives out first.

What it costs per building

Pricing is per mini-split and per compressor, and condition does not change it. A unit that comes out of a three-year tenancy black-specked costs the same as a dusty one — so you can write the turnover number down before you look inside.

$199 is the visit minimum, so one apartment costs the same whether it holds one mini-split or you are only between tenants in one of six. With several buildings, batch them: hold the non-urgent ones and run them the same week. The rental and commercial service handles multi-unit scheduling and per-mini-split records; the deep cleaning service lists what one visit includes.

Landlord questions

Related: short-term rentals and guest complaints, cleaning intervals, the full price list, and the Laconia page for the city rental stock.