External Static Pressure

External Static Pressure can best be deﬁned as the pressure difference (drop) between the Positive Pressure (discharge) and the Negative Pressure (intake) sides of the blower. External Static Pressure is developed by the blower as a result of resistance to airﬂow (Friction) in the air distribution system EXTERNAL to the VERT-I-PAK cabinet.

Resistance applied externally to the VERT-I-PAK (i.e. duct work, ﬁlters, etc.) on either the supply or return side of the system causes an INCREASE in External Static Pres- sure accompanied by a REDUCTION in airﬂow.

External Static Pressure is affected by two (2) factors.

1.Resistance to Airﬂow as already explained.

2.Blower Speed. Changing to a higher or lower blower speed will raise or lower the External Static Pressure accordingly.

These affects must be understood and taken into consideration when checking External Static Pressure/Airﬂow to insure that the system is operating within design conditions.

Operating a system with insufﬁcient or excessive airﬂow can cause a variety of different operating problems. Among these are reduced capacity, freezing evaporator coils, premature compressor and/or heating component failures. etc.

System airﬂow should always be veriﬁed upon completion of a new installation, or before a change-out, compressor replacement, or in the case of heat strip failure to insure that the failure was not caused by improper airﬂow.

1.Set up to measure external static pressure at the supply and return air.

2.Ensure the coil and ﬁlter are clean, and that all the registers are open.

3.Determine the external static pressure with the blower operating.

4.Refer to the Air Flow Data for your VERT-I-PAK system to ﬁnd the actual airﬂow for factory-selected fan speeds.

5.If the actual airﬂow is either too high or too low, the blower speed will need to be changed to appropriate setting or the ductwork will need to be reassessed and corrections made as required.

6.Select a speed, which most closely provides the required airﬂow for the system.

7.Recheck the external static pressure with the new speed. External static pressure (and actual airﬂow) will have changed to a higher or lower value depending upon speed selected. Recheck the actual airﬂow (at this "new" static pressure) to conﬁrm speed selection.

8.Repeat steps 8 and 9 (if necessary) until proper airﬂow has been obtained.

EXAMPLE: Airﬂow requirements are calculated as follows: (Having a wet coil creates additional resistance to airﬂow. This addit ional resistance must be taken into consideration to obtain accurate airﬂow information.

Checking External Static Pressure

The airflow through the unit can be determined by measuring the external static pressure of the system, and consulting the blower performance data for the speciﬁc VERT-I-PAK.

Determining the Indoor CFM: Chart A – CFM

			Model
	VEA09/VHA09		VEA12/VHA12		VEA18/VHA18
ESP (")	Low	High	Low	High	Low	High
.00"	340	385	420	470	430	480
.10"	300	340	350 *	420 **	400	450
.20"	230	280	290	350	340	400
.30”	140	190	250	300	290	330

Highlighted values indicate rated performance point. Rated performance for

*VEA12

Rated Performance for

**VHA12

		Model
	VEA24/VHA24
ESP (")	Low		High
.00"	690		740
.10"	610		700
.20"	560		640
.30"	510		580
.40"	450		520

Highlighted values indicate rated performance point.

H)A09K25L, H)A12K50L, H)A09K50L, H)A24K10L, H)A24K25L specifications

Friedrich R410A is a refrigerant blend that has become a cornerstone in the HVAC industry, particularly for air conditioning systems. This hydrofluorocarbon (HFC) is known for its efficiency and environmentally friendly properties, making it a popular alternative to older refrigerants like R22.

One of the main features of R410A is its exceptional thermal efficiency. It has a higher cooling capacity compared to R22, which allows for smaller and more efficient equipment. This efficiency translates to reduced energy consumption and lower operating costs for users. Additionally, the higher pressure capability of R410A enables the design of more compact systems, which is particularly beneficial for residential and commercial applications where space is often limited.

R410A is characterized by its zero ozone depletion potential (ODP), which is a significant advantage over its predecessors. This makes it a more environmentally responsible choice, aligning with global initiatives to phase out substances that harm the ozone layer. However, it is essential to note that while R410A does not deplete the ozone, it does have a global warming potential (GWP) of approximately 2,088, making it less favorable in terms of climate impact compared to natural refrigerants.

In terms of technology, R410A is typically utilized in systems that are designed specifically for this refrigerant. Equipment compatible with R410A often features advanced components that can handle the higher pressures required. Many modern air conditioning systems equipped with R410A also incorporate variable-speed compressors and advanced electronic controls, enhancing overall performance and comfort.

Additionally, R410A systems often come equipped with variable refrigerant flow (VRF) technology, which allows for precise temperature control in multiple zones of a building. This versatility makes R410A an ideal choice for both residential and commercial installations, providing optimal comfort throughout various spaces.

In summary, Friedrich R410A stands out due to its high energy efficiency, zero ozone depletion potential, and suitability for modern HVAC technologies. As the industry moves towards more sustainable practices, R410A serves as a reliable refrigerant that balances performance with environmental responsibility. It’s a significant choice for anyone looking to invest in efficient and eco-friendly heating and cooling solutions.

Friedrich H)A24K25L, R410A, H)A12K25L, H)A09K34L, H)A12K50L, H)A12K34L External Static Pressure

Models: H)A09K25L H)A12K50L H)A09K50L H)A24K10L H)A24K25L H)A24K34L H)A18K34L H)A12K34L H)A09K34L H)A24K75L H)A18K25L H)A24K50L H)A12K25L R410A