Other HD Applications List of Simple HD Desktop Apps

Hands Down Software offers a wide variety of simple HVAC desktop applications including apps for acoustical analysis, climatic data, fresh-air calcs, IP-SI conversions, duct design, and much more. All of these apps display both IP and SI units:


HDClimatic provides easy PC based outside air design conditions for over 1,459 domestic and international locations. Winter Heating, Summer Cooling and Wind Data are all based on ASHRAE's 1997 Fundamentals Handbook and are displayed on a single window for easy viewing.

Drop-down selection boxes allow the user to quickly view any psychrometric design variable desired. Both IP and SI Units are provided as well as cities all over the world in most countries.


HDFreshAir provides fresh air estimates based on ASHRAE Standard 62.1-2004. This design tools provides guidance when determining approximate outside air volumes recommended to provide proper indoor air quality.

HDFreshAir is a reflection of Table 6.1 from ASHRAE Standard 62.1-2004. Both IP and SI units are fully supported by HDFreshAir


HDAcoustic accepts source sound power levels in the standard octave bands and based on geometries and construction of the housing plenum, estimates sound power levels at openings in the plenum or air handling unit, as well as estimating radiated sound power levels.

While standard absorption and TL coefficients are pre-loaded in the program, HDAcoustic is extremely flexible, allowing you to input your own custom coefficients providing acoustical estimates for any plenum or AHU construction.

Multiple sound sources and multiple openings are fully supported by HDAcoustic.


HDConvert provides IP (inch-pound or english) units of measure to SI (standard international) units of measure conversions.

Unit conversions include length, area, volume, pressure, velocity, flow rates, weights, concentrations, energy, power, angles, rotation speed and more.

HDConvert provides the user the ability to Add / Edit / Delete unit of measure conversions, enabling an unlimited conversion capability.


HDComfort predicts human thermal response to the environment using several thermal comfort models, including PMV-PPD, ET*-DISC.

HDComfort allows you to calculate the predicted thermal comfort for a human at a point in space.

The program references ASHRAE Standard 55 and ISO Standard 7730.

Both IP and SI units are fully supported by HDComfort.


HDDuctDesigner allows you to calculate quick and accurate answers for duct size and/or pressure drops.

HDDuctDesigner calculations can be performed at Standard Air Conditions, or calculated based on Actual Air (corrected for temperature, humidity and altitude).

HDDuctDesigner performs calculations for Round, Rectangular and Oval Ducts and for virtually any length of duct.

Both IP and SI units are fully supported by HDDuctDesigner.


HDEvapCool allows you to easily obtain evaporative or "swamp" cooling performance in seconds. HDEvapCool properly corrects for altitude and allows the user to specify cooler size and calculates effectiveness, or the user can specify effectiveness and HDEvapCool calculates the cooler size needed.

Both IP and SI units are fully supported by HDEvapCool.


HDElectHeat allows you to easily obtain electric heater performance in seconds. HDElectHeat properly corrects for altitude and allows the user to specify heater size and input either leaving air temperature or heating kW. HDElectHeat also checks design for safety parameters such as watt density.

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