Facilities & Energy

HVAC Cooling Load Calculator

Area-based budgeting scenario with an assumed 0.9 electrical kW per refrigeration ton.

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1 Inputs

Minimum: 1

Minimum: 0

Minimum: 0

2 Results

Cooling load
5.8 tons
Cooling load (BTU/h)
70,000
Cooling load (kW)
20.5 kW
Est. running cost
$1,260/yr
Q(ton) = A × q / 12000; Pₑ = 0.9Q
Area-based budgeting scenario with an assumed 0.9 electrical kW per refrigeration ton. It has no guaranteed accuracy and is not equipment sizing. Obtain a building-specific heat-load calculation covering climate, envelope, ventilation and internal gains.

Worked example

Example values are illustrative. Replace them with your measured data.

InputValue
Floor area2000 ft²
Space typeOffice, typical (~35)
Electricity rate (for cost)0.12 $/kWh
Cooling hours / year2000 h

Cooling load: 5.8 tons

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About this calculator

How it works

You enter floor area (ft²), a space type that sets a BTU per ft² factor, electricity rate and cooling hours. Load = area × factor in BTU/h; tons = BTU/h ÷ 12,000; thermal kW = BTU/h ÷ 3,412. Running cost assumes 0.9 kW of electricity per ton.

Worked example (illustrative inputs)

2,000 ft² of typical office at 35 BTU/ft²: 70,000 BTU/h = 5.8 tons ≈ 20.5 kW thermal. The suggested unit rounds up to the next half ton, 6 tons. Cost ≈ 5.83 × 0.9 × 2,000 × $0.12 ≈ $1,260 per year.

How to read the result

This is a rule-of-thumb figure for early sizing and budgeting. It does not account for climate, insulation, glazing, orientation or internal gains.

When to use it

Use it for a first budget or to sanity-check a quote. Use a full load calculation for the actual design.

À propos de ce calculateur

Traduction (brouillon) — à relire.

Fonctionnement

Vous saisissez la surface (ft²), un type d'espace qui fixe un facteur BTU par ft², le tarif électrique et les heures de refroidissement. Charge = surface × facteur en BTU/h ; tonnes = BTU/h ÷ 12 000 ; kW thermiques = BTU/h ÷ 3 412. Le coût suppose 0,9 kW électrique par tonne.

Exemple chiffré (valeurs d'illustration)

2 000 ft² de bureau type à 35 BTU/ft² : 70 000 BTU/h = 5,8 tonnes ≈ 20,5 kW thermiques. L'unité suggérée est arrondie à la demi-tonne supérieure, 6 tonnes. Coût ≈ 5,83 × 0,9 × 2 000 × 0,12 $ ≈ 1 260 $ par an.

Lire le résultat

C'est un ordre de grandeur pour un premier dimensionnement et un budget. Il ne tient pas compte du climat, de l'isolation, des vitrages, de l'orientation ni des apports internes.

Quand l'utiliser

Utilisez-le pour un premier budget ou pour contrôler un devis. Faites un calcul de charge complet pour la conception réelle.

حول هذه الحاسبة

ترجمة (مسودة) — للمراجعة.

طريقة الحساب

تُدخل المساحة (ft²) ونوع الحيّز الذي يحدد معامل BTU لكل ft² وتعرفة الكهرباء وساعات التبريد. الحمل = المساحة × المعامل بوحدة BTU/h؛ والأطنان = BTU/h ÷ 12,000؛ وkW الحرارية = BTU/h ÷ 3412. وتفترض تكلفة التشغيل 0.9 kW كهربائية لكل طن.

مثال محسوب (قيم توضيحية)

2000 ft² من مكتب نموذجي عند 35 BTU/ft²: ‏70,000 BTU/h = 5.8 طن ≈ 20.5 kW حرارية. تُقرَّب الوحدة المقترحة إلى نصف الطن التالي، أي 6 أطنان. التكلفة ≈ 5.83 × 0.9 × 2000 × 0.12 $ ≈ 1260 $ سنويًا.

قراءة النتيجة

هذا رقم تقريبي للتحجيم المبكر والميزانية. لا يأخذ في الحسبان المناخ أو العزل أو الزجاج أو الاتجاه أو الأحمال الداخلية.

متى تستخدمه

استخدمها لميزانية أولية أو للتحقق من عرض سعر. واعتمد حساب أحمال كاملًا للتصميم الفعلي.

In one line

Area-based budgeting scenario with an assumed 0.9 electrical kW per refrigeration ton. It has no guaranteed accuracy and is not equipment sizing. Obtain a building-specific heat-load calculation covering climate, envelope, ventilation and internal gains.

Worked example

EXAMPLE

Illustrative values (the calculator defaults), not data from a real site.

Inputs
Floor area2000 ft²
Space typeOffice, typical (~35)
Electricity rate (for cost)0.12 $/kWh
Cooling hours / year2000 h
Results
Cooling load5.8 tons
Cooling load (BTU/h)70,000
Cooling load (kW)20.5 kW
Suggested unit6 tons
Est. running cost$1,260/yr

Frequently asked questions

How accurate is this cooling-load estimate?

It is a rule-of-thumb figure, generally good to within about plus or minus 20% for early budgeting. It does not account for climate zone, insulation, window area and orientation, air infiltration, or internal heat gains, all of which a formal Manual J or equivalent load calculation includes.

Why does space type change the BTU-per-square-foot figure so much?

Different space types generate very different internal heat loads — a server room packed with equipment produces far more heat per square foot than an empty warehouse, and a busy restaurant kitchen adds cooking-equipment heat on top of occupant load. The multiplier accounts for these typical internal gains.

Should I round up or down when choosing equipment size?

Round up to the nearest standard equipment size, which is what this tool's suggested unit already does, but avoid rounding up by more than necessary — oversizing causes short-cycling, poor humidity control and wasted energy, so bigger is not automatically better.

What electrical efficiency assumption does the running-cost estimate use?

It assumes roughly 0.9 kW of electrical input per ton of cooling delivered, representative of a reasonably efficient system. Older or less efficient equipment will draw more electrical power per ton, so your actual running cost could be higher than shown here.

When do I need a real Manual J calculation instead of this tool?

Use this tool only for rough early budgeting or a first conversation with a contractor. Before purchasing or installing equipment, get a proper Manual J (residential) or equivalent commercial load calculation that accounts for your specific climate, building envelope and occupancy — sizing purely off a rule of thumb can cause real comfort and energy problems.

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