Arkansas HVACR NewsMagazine March 2022

HVACR NewsMagazine March 2022

Tech News

In the state of Arkansas, we will seldom see this type of equipment selection criteria. Here high humidity is ever present, even in winter. For efficiency purposes we generally focus on a 75- degree dry bulb indoor, 63-degree wet bulb indoor temperature and a 95-to- 100-degree ambient temperature dependent upon location within the state. Please be careful to note heat pump performance in the winter on your Manual J. Some higher SEER heat pump products lose substantial capacity below 35 degrees. You may have to slightly oversize the cooling capacity to meet wintertime requirements, or you may need to find another brand or type of heat pump to deliver the necessary capacity for heating at lower ambient temperatures. Some inverter heat pumps offer performance to below zero.

Manual S adjustments for equipment-

Selecting equipment is an important part of the installation process. The capabilities of the installed equipment are when dependent upon ambient temperature, indoor wet bulb temperature delivered CFM fan setup selection. When we select equipment without regard of these factors, we guarantee the equipment will fail to provide the solutions we seek. The attached table gives examples for indoor dry bulb temperatures of 70 degrees, CFM settings for either 800 or 900 with an ambient temperature of 100 degrees. From these setting we would guess the system is installed somewhere humidity levels are low and daytime maximums are high. We must never forget to investigate where the condenser is located. If on the roof of an apartment building, we should probably move to a higher temperature demonstrated across the top of the chart.