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A cool room should have low enough heat gains to be easily cooled by a small single-zone cooling system such as a mini-split or a window air-conditioner as shown here
A ground source heat pump with an open-loop piping system using vertical injection and recharge
A ground-source heat pump has the same components as a standard air-to-air heat pump except that the liquid-to-refrigerant heat exchanger coil is located inside rather than outside
A ground-source heat pump with a closed-loop horizontal “Slinky™ “piping arrangement
A modern single-inlet direct evaporative cooler draws outside air through an 8- to 12-inch media filter
A properly sized cold climate heat pump can meet 100% of a home’s heating load in nearly any location in the United States
Concept behind an evaporative cooler – warm air is cooled as the air passes through a wet medium and gives up some of its heat to evaporate the water
Cooling air temperatures that can be achieved by a direct evaporative cooler at various outdoor conditions
Ductless indoor units like this one are controlled individually by handheld remote controllers.
Evaporative Cooler Sizing in ACH based on wet-bulb temperatures at 1% summer design conditions
Example expanded performance table from a 1.5-ton air conditioner
In a typical old style multi-inlet evaporative cooler, the blower fan draws outside air in through multiple media filters and blows it into the home
In heating mode, split system heat pumps absorb heat from the outside air and “pump” that heat to the indoor air handler unit, which releases it to the inside air.
National HVAC Design Report - Cooling Equipment Selection (Version 3 / 3.1 (Rev. 09))
Proper refrigerant charging is critical to maximizing performance for compression cooling systems
Right - An energy recovery ventilation (ERV) brings fresh air into the home while exhausting stale air. Both ducts pass through a heat exchanger where heat from the warmer duct is transferred to the cooler duct.
Right - This evaporative cooler is wall mounted to reduce leak effects and allow for ease of maintenance.
Right (decent): For a relatively high-capacity ccASHP sized per Approach 3 or 4 to meet nearly 100% of the heating load, this heat pump’s modulating zone has a decent overlap with the home’s heating load line, reducing short-cycling.
Right: Sized per Approach 1, this heat pump will have minimal short-cycling; since sized using Approach 1, it will require backup heat when temp is below 30°F but could still contribute significant heating down to heating design temp (-6°F) and lower
Right: Sized per Approach 3 or 4, this heat pump’s modulating zone has a large overlap with the home’s heating load line, resulting in minimal short-cycling; the unit may require a small amount of backup heat during the very coldest hours of winter.
Right: Sized per Approach 3, this heat pump’s modulating zone has a large overlap with the home’s heating load line; it will require backup heating but could still contribute significant heating for all hours of the heating season
The ductless air handler of a ductless heat pump can be mounted above the ceiling so that only the register is visible
The NEEP Cold Climate Air Source Heat Pump List allows users to search, sort, and filter for cold climate heat pumps by brand, model, product type, and ducting configuration; an advanced search provides helpful resources for sizing to the heating load
These plots compare sizing approaches in terms of the approximate annual heating load a heat pump might carry throughout the year for a hypothetical home in Minneapolis, MN.
This “high static ducted cassette” heat pump system is similar to a traditional centrally ducted system, serving several areas of a home from one indoor unit
This multi-split heat pump system incorporates several indoor units connected to just one outdoor unit; the indoor units include a wall-mounted unit, floor-mounted, ceiling cassette, and mini-air handler.
This plot shows a heat pump’s minimum and maximum cooling capacities overlaid with a home’s cooling load line, allowing a designer to assess how well-suited the equipment is for the specific home.
This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line as well as the annual heating load hours for the home, allowing a designer to assess how well-suited the equipment is for the specific home.
This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line, allowing a designer to assess how well-suited the equipment is for the specific home.
This plot shows a heat pump’s minimum and maximum heating capacities overlaid with a home’s heating load line, allowing a designer to assess how well-suited the equipment is for the specific home.
This single-zone mini-split ductless heat pump has only one indoor wall-mounted unit and one outdoor unit.
This traditional centrally ducted heat pump heats and cools the entire home through a network of ducts.
This upflow air handler for a traditional heat pump has an electric resistance auxiliary heating element located at the top of the unit (circled in red).
This wall-hung ductless indoor mini-split heat pump contains a fan, filter, and heating/cooling coil just like a traditional central air handler for a ducted heat pump system
Three-zone ductless mini-split system consisting of two wall-mounted and one ceiling-mounted indoor ductless units and one outdoor unit
Three-zone mini-split system consisting of one wall-mounted ductless unit, one ceiling-mounted ductless unit, and one ducted indoor unit, all connected to one outdoor unit
Typical coaxial coil (liquid-to-refrigerant heat exchanger) used in a ground-source heat pump