Under development

Known problems on this page right now: the proposed cooling efficiency used in the savings math is a fixed placeholder rather than the unit we recommend, and SEER and SEER2 ratings are compared without converting between them. Treat any dollar figure here as a rough sales estimate, not a utility-bill projection.

The calculation engine has not yet been checked against a reference tool on a real house. Treat every number here as a starting point to verify, not a finished answer.

Check the results before you act on them. Verify against the equipment data plate, the manufacturer's installation manual, and your own measurements. You are responsible for what you install — Cheek Heating & Cooling LLC is not liable for decisions made from this tool's output.

Free HVAC change-out proposal

Replacing a system? Enter what's there now plus a few things about the house. We size the new equipment to an ACCA Manual J 8 Abridged Edition load calculation and hand you a customer-ready side-by-side proposal — no signup, free PDF.

← Just need a load calc? Use the plain calculator instead

1 · The job

Customer / job name

Service address

Appliance location

Selects which code subsection the report's access checklist cites — each location carries a different set of requirements. Leave it blank if you don't know: the report will say the location wasn't recorded rather than assume one.

Equipment access and service space (optional)

Measurements taken at the appliance. Everything here is optional and every field may be left blank: a blank field is reported as not recorded, which is not the same as passing and not the same as measuring zero. Fill in whatever you took a tape to.

If the appliance is in an attic

Attic opening, clear width (in) The unobstructed opening, measured after any framing, trim or lining. Attic opening, clear length (in) Solid continuous flooring, width (in) The floored walkway from the opening to the appliance, and the working platform at it.

If the appliance is under a floor

Under-floor opening, rough-framed width (in) The framed opening, before any lining or trim. Under-floor opening, rough-framed length (in) Under-floor opening, clear width (in) The unobstructed opening. Rough-framed and clear are two different measurements taken at two different planes, so both are asked and neither is derived from the other. Record the one you actually took and leave the other blank. Under-floor opening, clear length (in) Clearance above the adjoining ground (in) Passageway or service space depth below adjoining grade (in) Below the code trigger depth the wall-lining requirement does not apply at all, so this figure decides whether the next question is even asked. How the appliance is supported The required ground clearance is not the same figure for the two, and for a ground-supported appliance it is a per-jurisdiction lookup, so no figure is printed here. Without this answer the clearance above cannot be judged at all. Are the passageway or service space walls lined with concrete or masonry extending above grade? Only reachable when the depth below grade above exceeds the code's trigger depth; at or under it the requirement does not apply.

Passageway to the appliance

Passageway height (in) Passageway width (in) Passageway length (ft) Measured in feet, not inches. Does that height and width hold for the entire length of the passageway, not just at the opening? This answers one thing only: entire length, or only at the opening. Answering yes cannot on its own buy the longer-passageway exception, because the height and width you entered above still have to clear that exception's own higher bar, and the checker re-reads them to decide. Where the exception does apply it raises or removes the length limit, so answer it honestly.

At the appliance

Working space at the appliance, depth (in) Level working space in front of the service side. Working space at the appliance, width (in) Largest appliance footprint, width (in) Used to check that the opening is large enough to get the appliance back out. Leaving this blank does not make the opening pass -- it makes that clause unevaluated, and the report says so. Largest appliance footprint, length (in) If the appliance is in a room or basement, does that room have a door?

Getting the appliance back out

Can the appliance be serviced and removed entirely through the opening, without entering the space? Answer yes only if it is true. Yes invokes the code exception, and the checker then stops evaluating the passageway geometry below rather than reporting it. Does removing the appliance require removing permanent construction? Does removing the appliance require removing another appliance first? Whether this is a defect depends on the jurisdiction, which the report resolves; record what is true on site either way.

Light and power at the appliance

Is there a lighting switch at the access opening? Is there a receptacle outlet near the appliance? Are exposed lamps protected from damage?

2 · What's there now

Add each piece you're replacing. Snap the rating plate to auto-fill, or type it in.

3 · About the house

Just enough to size the new system correctly.

Conditioned area (ft²)

Stories

Ceiling height (ft)

Occupants

Bedrooms (optional)

Roughly when was it built / last updated?

Windows (% of floor area)

% · typical homes are ~15%

10% is the lowest this tool models. A house with less glass than that is calculated as if it had 10%, which errs toward a larger system, not a smaller one.

Envelope tightness class (optional — overrides the era) Fireplaces (open hearth or vented gas) Blower-door CFM50 (only if tested)

Adjust insulation assemblies (optional)

Walls

Ceiling / attic

Floor

Soil around the slab

Window U-factor (NFRC sticker)

Window SHGC (NFRC sticker)

ACCA Manual J 8 Abridged Edition method. Equipment sizing follows ACCA Manual S principles (smallest standard size meeting the calculated load). This is design-assist documentation, not an ACCA-certified report.