SECTION 2 - HEATING DATA

Page S2-4

EMPIRICAL TRACKING

The data supplied below is an example of the PCS1’s actual performance near Jacksonville,

Florida during 1989. It can be observed that the PCS1 raised the pool’s temperature from 3 to 8º F

in a single day. A more typical rise in the pool’s temperature is 1 to 2º F per day. Thus, over the

course of two weeks, the pool is raised to the desired swimming temperature. The pool in the

example below used a pool blanket during periods of extended non-use.

The format provided below is a good one to use for determining the overall performance of

the PCS1 in your own installation. Take the temperature readings at the same time each morning

[7-9 a.m.] and each afternoon [4-6 p.m.].

EMPIRICAL DATA

Date
4/19
4/20
4/21
4/22
4/23
4/24
4/25
4/26
4/27
5/2
5/2

Air Temp
87
80
74
83
85
88
90
90
90
84
80

Conditions
Sunny
Overcast
Cloudy
Sunny
Sunny
Sunny
Sunny
Sunny
Sunny
Sunny
Sunny

Pool ºF a.m.
82
85
---
83
86
87
89
90
96
84
86

Pool ºF p.m.
87
88
86
88
91
92
94
98
stopped heat
90
91

ºF Gained
5
3
---
5
5
5
5
8

6
5

What is the PCS1 capable of doing? The following curves show designed verified

performance. The performance curves assume constant temperature differentials. In reality, the

temperature differentials will vary somewhat throughout the course of the solar heating day.

SECTION 2 - HEATING DATA

Page S2-5

PCS1 Operating Curves

FLOW RATE IN GPM

These operating curves show the heat transfer range of the PCS1. By knowing the flow

rate in gallons per minute, the attic's temperature and the pool's temperature -- both the BTU

hourly rate of heat transfer and the output rise in degrees Fahrenheit from the PCS1 can be

accurately predicted.

Example: If the flow rate is 30 gpm and the temperature differential between the attic and

the swimming pool is 32º F, the output rise will be approximately 4º F [PCS1 output temperature

minus input temperature]. This can be found by simply locating the flow rate on the horizontal

scale and going up vertically on the graph until you find the curve with the correct temperature

differential between the attic and the pool. Discussion continues on the next page.

SECTION 2 - HEATING DATA

Page S2-6

This is the attic temperature minus the swimming pool temperature. Then, simply draw a

horizontal line to the left scale from the curve and read the output rise in ºF. An example of a 32º F

temperature differential is an attic at 110º F and a swimming pool at 78º F.

Observe that as flow rate decreases for a given and constant temperature differential that the

output in º F will increase. Conversely, as flow rate increases, output temperature in º F will

decrease. The amount of heat transfer, however, is the same in both instances as long as the

temperature differential remains constant and is governed by the formula BTUS = 500 x ∆T x

GPM. The constant 500 is derived from the weight of water at 8.34 pounds per gallon times the

factor 60 used to convert the heat transfer to an hourly rate.

Observe also that as the temperature differential increases between the attic and the pool that

the rate of heat transfer also increases. The attic temperature should be measured inside the attic at

or near its peak. Once operating, the PCS1 will stratify the attic with lower temperatures at the attic

floor and higher temperatures at its peak. The PCS1 will simply take the solar radiation off the

inside of the roof at the same time it emanates into the attic. The roof will function as a massive

solar panel!