Home & Trade Calculator Center
89 focused tools for HVAC, ductwork, windows, doors, plumbing, electrical work, materials and job estimates.
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Complete calculator directory & formulas
Whole-House AC Size Estimate
Get a quick house cooling estimate with editable assumptions. Factors are CalculatorWiser planning scenarios, not coefficients published by ACCA or a calibrated climate model.
Formula: Load = area × selected starting rate × climate × insulation × ceiling × sun scenario factors; tons = BTU/h ÷ 12,000.
Preliminary planning only. This heuristic is not Manual J and may miss the actual load by a large amount. Confirm room-by-room sensible and latent loads with Manual J and select equipment with Manual S. Do not automatically round up or add a safety factor.
ACCA Manual J — residential loads
ACCA Manual S — equipment selection
Carrier — rough square-foot starting rule
Carrier — rough square-foot starting rule
Room & Window AC Size
Size a window or through-wall room AC using the ENERGY STAR area table and stated adjustments.
Formula: ENERGY STAR table capacity × sun adjustment + 600 × occupants above two + 4,000 for a kitchen.
Table assumes an 8-foot ceiling. A room table is not a whole-house or multi-zone mini-split design. High ceilings, unusual glass and disconnected rooms need further evaluation.
Heat Pump Cooling Estimate
Estimate the cooling side of a heat pump. Heating performance must be checked separately at local winter design temperature.
Formula: Cooling BTU/h = area × rate × scenario factors.
Preliminary planning only. This heuristic is not Manual J and may miss the actual load by a large amount. Confirm room-by-room sensible and latent loads with Manual J and select equipment with Manual S. Do not automatically round up or add a safety factor. This does not select a heat pump or size backup heat.
ACCA Manual J — residential loads
ACCA Manual S — equipment selection
Carrier — rough square-foot starting rule
Carrier — rough square-foot starting rule
Heating Load Planning Estimate
Explore a user-selected heat-loss assumption and convert the result to thermal kW.
Formula: Heating load = area × assumed heat loss per square foot.
This is a scenario, not a furnace or heat-pump sizing calculation. Confirm climate, envelope, infiltration and equipment output with a heating load calculation.
ACCA Manual J — residential loads
Cooling BTU, Tons & kW
Convert cooling capacity into tons and thermal kilowatts. Thermal kW measures cooling output, not electricity input.
Formula: Tons = BTU/h ÷ 12,000; thermal kW = BTU/h ÷ 3,412.142.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
ACCA Manual J — residential loads
HVAC Airflow from Tonnage
Estimate blower airflow using an editable airflow assumption. The 400 default is an example, not a universal operating setting.
Formula: CFM = tons × chosen CFM per ton.
Use manufacturer blower tables and humidity requirements. Airflow per ton varies with equipment and operating conditions.
Round Duct Size by Airflow
Find the mathematical inside diameter that carries a selected airflow at a selected velocity.
Formula: Area = CFM ÷ velocity; diameter (in) = 12 × √(4 × area ÷ π).
Velocity-only preliminary sizing. Friction, fittings, flex compression, noise, available static pressure and Manual D may require a different size.
Rectangular Duct Size by Airflow
Calculate one rectangular duct dimension from airflow, target velocity and available width.
Formula: Required area (sq in) = 144 × CFM ÷ velocity; height = area ÷ width.
Area/velocity sizing only. Check aspect ratio, pressure losses and Manual D before installation.
Round Duct Air Velocity
Calculate the average air speed through a round duct.
Formula: Velocity = CFM ÷ [π × (diameter ÷ 24)²].
Average velocity does not prove the duct has acceptable pressure loss or noise.
Rectangular Duct Air Velocity
Find average velocity in a rectangular duct using actual inside dimensions.
Formula: Velocity = CFM × 144 ÷ (width × height).
Check pressure loss and equipment data separately.
Round / Rectangular Equal-Area Duct
Compare cross-sectional area and hydraulic diameter.
Formula: Equal-area round diameter = √(4 × width × height ÷ π); hydraulic diameter = 2wh ÷ (w+h).
Equal area and hydraulic diameter are not equal-friction replacement sizes. Do not substitute duct shapes based on area alone.
Duct Design Friction Rate
Allocate remaining blower pressure over the critical supply-and-return path, including fitting equivalent lengths.
Formula: Available duct pressure = external static − component losses; friction rate = available duct pressure × 100 ÷ total effective length.
Use blower data at design airflow and the correct pressure measurement boundary. Do not subtract an internally accounted component twice. This is one Manual D input, not a finished design.
Duct Pressure Loss from Friction Rate
Estimate path pressure loss from a known friction rate and effective length.
Formula: Pressure loss = friction rate × effective length ÷ 100.
Input friction must match airflow and duct construction. Add component losses separately; do not count fittings twice.
Duct Total Effective Length
Combine straight duct and manufacturer/design-reference fitting equivalent lengths for one selected path.
Formula: Total effective length = straight path length + fitting equivalent lengths.
Use fitting-specific values; generic elbows do not all have the same equivalent length.
Supply Register Free Area
Estimate free area and corresponding gross face area for a supply register.
Formula: Free area = CFM ÷ velocity; gross face area = free area ÷ free-area fraction.
Manufacturer throw, noise and pressure-drop ratings control final selection. Nominal grille dimensions may differ from usable face area.
Return Air Grille Free Area
Estimate a return grille area for your selected airflow and velocity.
Formula: Gross face area (sq in) = CFM ÷ velocity × 144 ÷ free-area fraction.
Filters and grille pressure losses require manufacturer data. This does not size the return duct or guarantee quiet operation.
Room Airflow from Sensible Load
Translate a known sensible cooling load into airflow using standard-air assumptions.
Formula: CFM = sensible BTU/h ÷ (1.08 × temperature difference).
Do not enter total load including latent moisture. The 1.08 factor varies with air density and altitude.
Air Changes per Hour
Calculate how many room volumes a selected airflow represents per hour.
Formula: ACH = airflow × 60 ÷ room volume.
Recirculated air is not fresh-air ventilation. This does not establish code-required ventilation.
Airflow from Target Air Changes
Find airflow for a user-selected air-change target.
Formula: CFM = room volume × chosen ACH ÷ 60.
Target ACH is user selected and not a code recommendation. Specify outdoor/exhaust airflow and verify ventilation requirements.
Duct Insulation Wrap Quantity
Estimate rectangular duct wrap area including a chosen overlap and waste.
Formula: Wrap area = [(2w + 2h + overlap) ÷ 12] × length × (1 + waste/100).
Allow for insulation thickness, fittings and transverse seams separately; check the wrap manufacturer’s stretch-out dimensions.
AC Electricity Operating Cost
Estimate AC electricity use from measured or assumed electrical input and actual runtime.
Formula: kWh = watts ÷ 1,000 × running hours × days; cost = kWh × rate.
Thermal cooling kW is not electrical input. Variable-speed power and runtime change with weather and load.
HVAC Efficiency Comparison
Compare cooling energy under the assumption that delivered cooling demand stays the same.
Formula: New cooling cost ≈ current cooling cost × old rating ÷ new rating.
Compare ratings on the same test basis; do not directly compare SEER and SEER2 without applicable conversion. Installation, ducts and humidity affect actual savings.
HVAC Filter Replacement Date
Plan a filter check or replacement date using the interval you choose.
Formula: Next date = last replacement date + chosen interval.
Use manufacturer instructions and actual filter condition; pets, dust and runtime can shorten intervals.
Window Opening Area
Measure identical openings and calculate their total square footage. Frame dimensions and visible glass dimensions are different.
Formula: Total area = width × height × count ÷ 144.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Door Opening Area
Measure identical openings and calculate their total square footage. Frame dimensions and visible glass dimensions are different.
Formula: Total area = width × height × count ÷ 144.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Sliding & Patio Door Area
Measure identical openings and calculate their total square footage. Frame dimensions and visible glass dimensions are different.
Formula: Total area = width × height × count ÷ 144.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Window Replacement Budget
Build a replacement budget from your own product and labor quotes.
Formula: Budget = count × (product + labor) + extras + product tax.
Costs are user inputs, not current local market prices. Verify tax treatment, permits, disposal and repair allowances.
Door Replacement Budget
Build a replacement budget from your own product and labor quotes.
Formula: Budget = count × (product + labor) + extras + product tax.
Costs are user inputs, not current local market prices. Verify tax treatment, permits, disposal and repair allowances.
Patio Door Replacement Budget
Build a replacement budget from your own product and labor quotes.
Formula: Budget = count × (product + labor) + extras + product tax.
Costs are user inputs, not current local market prices. Verify tax treatment, permits, disposal and repair allowances.
Window & Door Rough Opening
Calculate an opening using clearances from your exact product installation instructions.
Formula: Rough width = unit width + 2 × side clearance; rough height = unit height + top + bottom clearance.
Zero clearances are placeholders. Door slab dimensions are not prehung unit dimensions. This does not size headers or authorize structural changes.
Window Casing & Trim
Estimate opening perimeter material and a minimum stock-piece quantity.
Formula: Linear feet = (2 × height + width + optional bottom width) × count × faces ÷ 12; add waste.
Total-length stock count is a lower bound. Long cuts, miters and offcut reuse can require extra pieces.
Door Casing & Trim
Estimate opening perimeter material and a minimum stock-piece quantity.
Formula: Linear feet = (2 × height + width + optional bottom width) × count × faces ÷ 12; add waste.
Total-length stock count is a lower bound. Long cuts, miters and offcut reuse can require extra pieces.
Window & Door Weatherstripping
Estimate opening perimeter material and a minimum stock-piece quantity.
Formula: Linear feet = (2 × height + width + optional bottom width) × count × faces ÷ 12; add waste.
Total-length stock count is a lower bound. Long cuts, miters and offcut reuse can require extra pieces.
Window & Door Caulk Tubes
Estimate sealant for a rectangular joint cross section using cartridge volume.
Formula: Volume (cu in) = length × 12 × joint width × depth; tubes = volume ÷ (fl oz × 1.8046875), plus waste.
Round beads differ from rectangular joints. Follow product joint geometry, backer rod and depth requirements.
Window-to-Wall Area Ratio
Find the fraction of a wall occupied by windows.
Formula: Window-to-wall ratio = window area ÷ gross wall area × 100.
Use gross wall area including openings. This does not calculate solar gain or prove energy-code compliance.
Window Conductive Heat Transfer
Estimate steady-state conduction through rated windows. Lower U-factor reduces this component.
Formula: Heat transfer = U-factor × area × temperature difference.
Excludes solar gain, air leakage, shading and transient effects. Not a whole-house load calculation.
Window Solar Gain Scenario
Explore how glazing and shading change solar gain at a chosen instant.
Formula: Solar gain ≈ area × SHGC × incident solar flux × shading multiplier.
Solar flux is user supplied, not retrieved from ZIP code. Orientation, time and shading matter; this is not Manual J.
Window Screen Mesh & Frame
Estimate screen mesh area and frame length, with trimming allowance.
Formula: Mesh area = (width + 2 × allowance) × (height + 2 × allowance) × count ÷ 144; frame = perimeter.
Check corner connectors, spline, frame profile and cut instructions.
Curtain Width & Length
Plan finished panel quantity or a fabric cutting length from your mounting measurements.
Formula: Total curtain width = coverage width × fullness; panels = ceiling(total width ÷ panel width); cut length = drop + hem.
Measure from the actual rod or track. Fabric repeat, header style and shrinkage need separate allowance.
Blind Mounting Dimensions
Apply your chosen inside-mount deduction or outside-mount extension.
Formula: Order width = measured width + chosen total adjustment; order height = measured height + chosen total adjustment.
Some manufacturers make deductions themselves. Follow their ordering instructions to avoid subtracting twice.
Door Paint Quantity
Estimate paint for flat door faces using the label coverage.
Formula: Paint gallons = door face area × sides × count × coats ÷ coverage, plus waste.
Excludes edges, panels, jambs and texture allowances.
Pipe Water Volume
Calculate water held in a cylindrical pipe using inside diameter.
Formula: Gallons = π × (inside diameter ÷ 2)² × length × 12 ÷ 231.
Nominal pipe size is not necessarily inside diameter.
Pipe Flow from Velocity
Convert an assumed water speed into pipe flow.
Formula: GPM = cross-sectional area (sq ft) × velocity × 448.831.
This does not establish available flow from a supply pressure or size a code-compliant plumbing system.
Water Pipe Velocity
Find water velocity from flow and inside pipe diameter.
Formula: Velocity = GPM ÷ 448.831 ÷ cross-sectional area (sq ft).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Water Pipe Friction Loss
Estimate water-pipe friction pressure loss with Hazen–Williams.
Formula: Pressure loss (psi) ≈ 4.52 × length × GPM^1.852 ÷ (C^1.852 × diameter^4.87).
Applicable to conventional turbulent water flow. Excludes elevation, meters and valves unless included; not for gas, steam or laminar flow.
Drain Pipe Slope & Fall
Calculate vertical drop from your selected drain slope.
Formula: Fall (in) = run (ft) × slope (in/ft).
The slope is an input, not a code recommendation. Verify permitted slope, pipe size, venting and local requirements.
Hot Water Demand Scenario
Estimate hot water used by simultaneous fixtures over a chosen period.
Formula: Demand gallons = combined hot-water flow × minutes.
Fixture mixing, storage temperature, recovery and first-hour rating affect water-heater selection.
Water Heating Energy & Power
Estimate energy and average input power required to warm a batch of water.
Formula: Delivered BTU = gallons × 8.34 × temperature rise; input kWh = BTU ÷ 3,412.142 ÷ efficiency.
Excludes standby and distribution losses. Instantaneous heater selection requires manufacturer flow-versus-rise data.
Watts, Amps & Volts
Calculate DC or single-phase real electrical power.
Formula: Single-phase real power (W) = volts × amps × power factor.
Not for three-phase power or circuit/breaker selection. Equipment startup and nameplate requirements matter.
Current from Electrical Load
Estimate current drawn by a known real-power load.
Formula: Single-phase amps = watts ÷ (volts × power factor).
Does not establish permitted wire size, breaker size or service capacity.
Two-Wire Voltage Drop
Estimate a two-wire DC or resistive single-phase circuit drop from user-supplied conductor resistance.
Formula: Voltage drop ≈ 2 × one-way length × amps × resistance ÷ 1,000.
Neglects reactance and temperature changes. Resistance must match the conductor. This does not check ampacity, grounding or code compliance.
Appliance Energy & Cost
Estimate appliance electricity cost using actual average power and runtime.
Formula: kWh = W ÷ 1,000 × hours × days; cost = kWh × price per kWh.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Connected Electrical Load
Add identical connected loads and show a resistive current equivalent.
Formula: Connected watts = count × watts each; resistive single-phase current = total watts ÷ volts.
Connected load is not a residential service load calculation. Code demand factors and circuit requirements are not included.
Lumber Board Feet
Calculate lumber volume in board feet.
Formula: Board feet = thickness × width × length × count ÷ 12.
Use the supplier’s pricing basis; nominal and actual dimensions differ.
Wall Stud Quantity
Estimate a straight-wall stud count with explicit extras.
Formula: Basic studs = ceiling(wall length × 12 ÷ spacing) + 1; add extra studs.
Quantity only. Does not design bearing walls, headers, spans or structural connections.
Joist Quantity
Estimate joist quantity across a chosen spacing layout.
Formula: Count = ceiling(layout distance × 12 ÷ spacing) + 1 + extras.
Does not select joist size, span, species, load rating or hangers.
Rafter Geometry
Find a geometric slope length for a simple rafter.
Formula: Sloped length = (run + horizontal overhang) × √(1 + (pitch/12)²).
Not a cut list or structural design. Ridge deduction, birdsmouth, heel height and end cuts need separate layout.
Stair Rise & Run Layout
Explore equal risers and a straight flight with the upper floor serving as the final landing.
Formula: Risers = ceiling(total rise ÷ target); actual rise = total rise ÷ risers; treads = risers − 1.
This does not certify code compliance, landings, headroom, guards or stringer strength.
Deck Board Coverage
Estimate deck-board rows and total lineal footage.
Formula: Rows = ceiling[(deck width × 12 + gap) ÷ (board width + gap)]; lineal feet = rows × deck length.
No structural design. Board stock lengths, seams and diagonal layouts change purchasing quantities.
Roof Area from Pitch
Estimate a simple roof with a uniform pitch from its horizontal projected area.
Formula: Sloped roof area = plan area × √(1 + (pitch/12)²); add waste.
Mixed pitches, dormers, valleys and complex roofs should be measured as separate sections.
Roof Shingle Bundles
Estimate shingle bundles using your product’s actual coverage.
Formula: Bundles = ceiling(area × waste factor ÷ coverage per bundle).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Metal Roof Panel Rows
Calculate rows of full-length panels for one rectangular roof section.
Formula: Panels = ceiling(section width × 12 ÷ effective cover width).
Use effective cover width after side laps. End laps, trims, fasteners and expansion need manufacturer guidance.
Roof Underlayment Rolls
Estimate rolls using coverage after required laps.
Formula: Rolls = ceiling(area × waste factor ÷ effective roll coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Gutter Material Length
Estimate gutter stock length and section count.
Formula: Purchased length = measured length × waste factor; sections = ceiling(length ÷ stock length).
Not a drainage-capacity calculation. Roof catchment, rainfall, slope and outlets determine gutter/downspout sizing.
Concrete Slab Volume
Estimate ready-mix volume and bag quantity using actual product yield.
Formula: Cubic feet = length × width × depth ÷ 12; cubic yards = cubic feet ÷ 27; bags = ceiling(adjusted volume ÷ bag yield).
Quantity only. Foundation depth, reinforcement and structural dimensions require appropriate design.
Concrete Footing Volume
Estimate ready-mix volume and bag quantity using actual product yield.
Formula: Cubic feet = length × width × depth ÷ 12; cubic yards = cubic feet ÷ 27; bags = ceiling(adjusted volume ÷ bag yield).
Quantity only. Foundation depth, reinforcement and structural dimensions require appropriate design.
Concrete Block Quantity
Estimate masonry units using face dimensions including the intended mortar joint.
Formula: Units = ceiling(net wall area × waste factor ÷ module face coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Brick Quantity
Estimate masonry units using face dimensions including the intended mortar joint.
Formula: Units = ceiling(net wall area × waste factor ÷ module face coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Mortar Bag Quantity
Estimate mortar bags using coverage for your brick/block and joint specification.
Formula: Bags = ceiling(wall area × waste factor ÷ product coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Drywall Sheet Quantity
Estimate drywall sheets from net wall and ceiling area.
Formula: Sheets = ceiling(surface area × waste factor ÷ sheet area).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Joint Compound Quantity
Estimate compound containers using coverage for the intended finish level.
Formula: Containers = ceiling(area × waste factor ÷ label coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Wall Paint Quantity
Estimate wall paint including chosen coats and waste.
Formula: Gallons = area × coats × waste factor ÷ label coverage.
Surface texture, porosity and application method change coverage.
Wallpaper Rolls
Estimate wallpaper rolls after allowing for pattern matching in the coverage input.
Formula: Rolls = ceiling(area × waste factor ÷ usable coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Flooring Box Quantity
Estimate boxes using product-specific coverage and a chosen waste allowance.
Formula: Purchase units = ceiling(area × waste factor ÷ product coverage).
For grout, use coverage specific to tile size, thickness and joint width. Layout and cut loss can change quantities.
Tile Quantity
Estimate tiles using product-specific coverage and a chosen waste allowance.
Formula: Purchase units = ceiling(area × waste factor ÷ product coverage).
For grout, use coverage specific to tile size, thickness and joint width. Layout and cut loss can change quantities.
Grout Quantity
Estimate bags using product-specific coverage and a chosen waste allowance.
Formula: Purchase units = ceiling(area × waste factor ÷ product coverage).
For grout, use coverage specific to tile size, thickness and joint width. Layout and cut loss can change quantities.
Tile Rows & Columns
Estimate an edge-start straight grid and full tile count before cut reuse.
Formula: Rows = ceiling[(room length × 12 + joint) ÷ (tile length + joint)]; similarly for columns.
Centered, diagonal and patterned layouts differ. Expansion joints and cut reuse are not modeled.
Insulation Package Quantity
Estimate insulation packages using coverage at the required installed thickness.
Formula: Packages = ceiling(area × waste factor ÷ package coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Layer R-Value Comparison
Compare nominal resistance of layers in series.
Formula: Series-layer R = R1 + R2; U ≈ 1 ÷ R.
Whole-wall R differs because of framing bridges, air films and installation defects. Use consistent US R-value units.
Topsoil Volume
Estimate bulk volume or bag quantity for a rectangular area.
Formula: Cubic yards = length × width × depth ÷ 12 ÷ 27; add allowance; bags = ceiling(cu ft ÷ bag volume).
Settling and compaction vary by material; select your own allowance.
Mulch Volume
Estimate bulk volume or bag quantity for a rectangular area.
Formula: Cubic yards = length × width × depth ÷ 12 ÷ 27; add allowance; bags = ceiling(cu ft ÷ bag volume).
Settling and compaction vary by material; select your own allowance.
Gravel Volume
Estimate bulk volume or bag quantity for a rectangular area.
Formula: Cubic yards = length × width × depth ÷ 12 ÷ 27; add allowance; bags = ceiling(cu ft ÷ bag volume).
Settling and compaction vary by material; select your own allowance.
Sod Piece Quantity
Estimate sod units and total coverage with a waste allowance.
Formula: Pieces = ceiling(lawn area × waste factor ÷ piece coverage).
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Irrigation Zone Demand
Add emitter flow and estimate water used by a zone.
Formula: Zone GPM = count × emitter GPH ÷ 60; gallons = zone GPM × minutes.
Check supply pressure, nozzle data, pipe losses and local watering requirements.
Trade Job Quote
Build a quote from costs, markup and optional tax.
Formula: Cost = materials + hours × rate + extras + overhead; subtotal = cost × (1 + markup/100); add selected tax.
Markup and profit margin differ. Tax treatment varies; choose the correct taxable amount outside this simplified scenario.
Trade Labor Hours
Estimate labor effort and elapsed time from your productivity assumption.
Formula: Worker-hours = units ÷ productivity; elapsed crew hours = worker-hours ÷ crew.
Crew scaling assumes equal productivity without coordination or site delays.
Markup & Profit Margin
Compare markup on costs with profit margin on revenue.
Formula: Profit = price − cost; markup = profit ÷ cost × 100; margin = profit ÷ price × 100.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Job Sales Tax
Calculate tax on the amount you identify as taxable.
Formula: Tax = taxable amount × rate/100; total = taxable amount + tax.
No jurisdiction lookup. Verify whether materials, labor or the full invoice are taxable.
Project Contingency Budget
Add a chosen contingency and compare with your available budget.
Formula: Planned budget = base × (1 + contingency/100); remaining = available − planned.
Estimate quantities from measured dimensions. Check product coverage, ordering sizes and installation instructions before buying.
Understanding AC and ductwork estimates
A whole-house square-foot estimate is a starting scenario. Climate, insulation, air leakage, windows, solar exposure, people and duct location can materially change the actual cooling requirement. A large unit can cool the air before removing enough moisture.
Manual J calculates sensible and latent loads. Manual S selects equipment using performance data. Manual D designs the duct system using room airflow, the blower’s pressure capability and the losses of ducts, fittings and components. Velocity-only duct dimensions do not complete that design.
One ton of cooling equals 12,000 BTU per hour. Thermal cooling kW describes heat removed; electrical input kW describes power consumed. Room/window AC estimates use the ENERGY STAR room table separately from the whole-house scenarios.
For heat pumps, cooling results alone cannot select the system: heating output at winter design temperature and backup heat need a separate evaluation. Material calculators estimate quantities; they do not size structural members or establish electrical or plumbing code compliance.
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