King County HVAC GuideKnow what you're buying
King County homeowners

Buying a new HVAC system?

Understand your options before you spend thousands of dollars. Learn how sizing, equipment selection, ductwork, installation quality and contractor proposals fit together.

Read the buyer's guide Get local quotes

Independent educational resource. Contractor relationships are disclosed — this guide is published by Allred Heating, Cooling, & Electrical; see About.

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Replacing your system?

Know what should be included in a proposal.

Replacement basics →
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Considering a heat pump?

Understand sizing, performance and fit.

Heat pump guide →
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Already have quotes?

Compare the details — not just the price.

Compare quotes →
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Not sure what you need?

Start with the basics and work forward.

Repair or replace? →

The buyer's guide

Four questions should drive the conversation. A good HVAC replacement starts with the home and the design — not with a box on a truck. ACCA's residential design framework covers load calculation, equipment selection and duct design.

1

Manual J

Estimate the home's heating and cooling loads.

2

Manual S

Select equipment using loads, climate and manufacturer performance data.

3

Manual D

Evaluate or design the duct system and airflow.

4

Install + verify

Make sure the installation, setup and commissioning match the design.

Manual J, S & D in plain English →

HVAC systems

Learn the system before you choose the system. Different homes and priorities can lead to different solutions. The goal here is to understand the tradeoffs before you talk price.

Heat Pumps

Heating and cooling from one system, with performance that depends on equipment, sizing, installation and climate.

Learn & get quotes →

Furnaces

Understand fuel type, efficiency, capacity, airflow and what should be included in replacement work.

Learn & get quotes →

Air Conditioning

Compare capacity, efficiency, matched equipment and installation scope instead of shopping by tonnage alone.

Learn & get quotes →

Ductless / Mini-Split

Explore when zoned or ductless equipment can make sense and what installation details matter.

Learn & get quotes →

Compare quotes

Don't compare HVAC proposals on price alone. Two proposals can look similar while including very different equipment, design work, warranties and installation scope.

01

Equipment

Look for manufacturer and exact model numbers, capacity, efficiency and matched components.

02

Design

Ask how the contractor determined capacity and whether existing ductwork and airflow were evaluated.

03

Installation

Review permits, electrical work, refrigerant work, condensate, startup/commissioning, cleanup and warranty terms.

New · AI assisted

Have quotes already?

Upload photos or PDFs of two or three HVAC proposals and turn them into a side-by-side checklist comparison of price, equipment, sizing, ductwork, installation scope, permits and warranties.

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Resources

Build confidence before the sales appointment. Our education is designed around the questions homeowners actually need answered.

HVAC Replacement Cost

Understand the factors that move a project price: equipment, capacity, efficiency, ductwork, electrical, permits and installation complexity.

Heat Pump Cost

Look at upfront cost alongside equipment performance, installation requirements and expected operating considerations.

Repair vs. Replace

Think through equipment age, repair history, comfort, reliability and the condition of the overall system.

HVAC Sizing

Learn why a contractor should consider the home's actual heating and cooling loads rather than relying only on rules of thumb.

Manual J, S & D

Plain-English explanations of load calculation, equipment selection and duct design.

Quote Checklist

A homeowner-friendly checklist for comparing contractor proposals and identifying missing scope.

Service area education

Helpful HVAC buying guides across King County — local planning questions, answered without confusing an educational guide for an installing contractor.

Seattle

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Bellevue

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Auburn

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Kent

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Renton

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Federal Way

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

Kirkland

Understand HVAC sizing, compare itemized bids, and verify Washington contractor registration.

King County

County-wide guidance on heat pumps, sizing, ductwork and complete, comparable bids.

Tell us what you're looking for.

Answer a few questions about your home and your project. Your request goes to Allred Heating, and we respond with next steps and a site-specific, itemized proposal — not an advertised starting price.

Request local HVAC quotes Call 206-418-9153