- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
A Manual J load calculation is the ACCA standard for working out how much heating and cooling a house needs, room by room. It accounts for insulation, windows, air leakage, orientation and local design temperatures. A heat pump sized from a load calculation runs longer, steadier cycles. An oversized one short-cycles, dehumidifies poorly and wears faster.
Most quotes in the DMV are still sized by rule of thumb or by matching the old unit. The companies below say on their own websites that they size equipment with a Manual J or a heat load calculation. That is a short list, and it is the first thing worth asking any installer about.
Ask for the load calculation report with the quote. It should list each room, the design temperatures used and the total heating and cooling load. Compare the equipment size in the quote to that total. If the house is getting air sealing or insulation first, ask for the calculation to be run on the improved house, because a tighter house needs a smaller system.
All 57: load calculation (manual j)
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Energy audit or air sealing
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Load calculation (Manual J)
- Furnaces and boilers
- Financing
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Emergency service
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Load calculation (Manual J)
- Ductless mini-splits
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Load calculation (Manual J)
- Furnaces and boilers
- Financing
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Load calculation (Manual J)
- Ductwork
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Dual-fuel or hybrid systems
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Energy audit or air sealing
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Energy audit or air sealing
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Load calculation (Manual J)
- Furnaces and boilers
- Rebate and EmPOWER help
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Load calculation (Manual J)
- Ductwork
- Furnaces and boilers
- Load calculation (Manual J)
- Load calculation (Manual J)
- Financing
- Emergency service
- Installs heat pumps
- Load calculation (Manual J)
- Ductwork
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Load calculation (Manual J)
- Ductwork
- Emergency service
- Load calculation (Manual J)
- Ductless mini-splits
- Furnaces and boilers
- Installs heat pumps
- Load calculation (Manual J)
- Ductless mini-splits
- Load calculation (Manual J)
- Ductwork
- Load calculation (Manual J)
- Emergency service
- NATE-certified technicians
- Load calculation (Manual J)
- Furnaces and boilers
Heat Pump Installers Who Do Load Calculations by city
- Frederick 4
- Columbia 3
- Gaithersburg 3
- Manassas 3
- Chantilly 2
- Essex 2
- Forest Hill 2
- Hagerstown 2
- Rockville 2
- Sterling 2
- Upper Marlboro 2
- Westminster 2
- Woodbridge 2
- Alexandria 1
- Annapolis 1
- Baltimore 1
- Crofton 1
- Dumfries 1
- Fairfax 1
- Finksburg 1
- Fort Washington 1
- Glen Burnie 1
- Gwynn Oak 1
- Halethorpe 1
- Hanover 1
- Jefferson 1
- Leesburg 1
- Manassas Park 1
- McLean 1
- Mt Airy 1
- Oakland 1
- Reisterstown 1
- Reston 1
- Rosedale 1
- Salisbury 1
- Silver Spring 1
- Waldorf 1
- Washington 1
- Williamsport 1
Other services
Before you hire
In Maryland, look up the company with the State Board of HVACR Contractors, and for home improvement contracts the Maryland Home Improvement Commission. In Virginia, HVAC tradesmen must hold state certification from the Department of Professional and Occupational Regulation, and contracting businesses are licensed by its Board for Contractors. In Washington DC, the Office of the Attorney General advises that refrigeration and air conditioning mechanics need a trade license and that most home improvement work needs a District permit. This directory does not verify licenses. Ask for the license number and look it up before you sign, and ask for a Manual J load calculation before anyone sizes a heat pump.