Pool/Spa Heater Information

Pool heater installation and maintenance information

-- [HAYWARD POOL HEATER SELECTION]

-- [OPERATION & MAINTENACE OF HAYWARD POOL HEATER]

- [GAS PIPE SIZING]

Heater Air Venting

Natural gas and liquid propane typically serve as the fuel source for pool and spa heaters. Yet combustion requires two ingredients: fuel and air. All too often, pool and spa heaters fail to perform properly (or at all) because they're starving for the latter ingredient, air. Of course, not only is adequate air supply needed for combustion, adequate exhaust venting is then needed for removal of post-combustion air. Failure to ensure sufficient combustion air supply will choke a heater, while insufficient post-combustion ventilation could result in potentially lethal exhaust problems. Certain aspects of post-combustion ventilation vary from one heater model to the next and some heaters are unable to be installed indoors. Prior to any installation, consult the specific product's installation manual for location and air supply specifications.

The other aspect of air supply - combustion air supply - is relatively consistent for all gas installations regulated by the C.S.A.

Sources of Air Supply 1. Air to the room is supplied FROM INSIDE the building. (A) The vents must provide: 1 square inch of free air per 1,000 BTU's (see Table A above). For air supply openings that communicate directly with adjacent rooms, the adjacent rooms must be of sufficient volume so that the combined volumes of all spaces meet the criteria for an unconfined space. The unconfined space volume requirement is "not less then 50 cubic feet per 1000 81UH. " This translates into 20,000 cubic feet of space (a 50' x 40' x1 0' room) for a 400,000 BTU heater. 2. Air to the room is supplied FROM the OUTDOORS. (B) If the air is supplied through horizontal ducts to the outdoors, they must provide: 1 square inch of free air per 2,000 BTU's (see Table B above). (C) If the vents are placed in an exterior wall that gets air from the outdoors OR from via vertical ducts which supply air from the outdoors, then the vents must provide: 1 square inch of free air per 4,000 BTU's (see Table C at right).

Air Supply (for combustion)

If the heating system is entirely outdoors (not enclosed), air supply will likely never be an
issue, unless trees or shrubbery have overgrown around the heater. Increasing numbers of pool owners are starting to partially or totally enclose the equipment pad - particularly in parts of the country where property sizes are getting smaller. So it's important for technicians to be aware that combustion air supply requirements for gas heaters vary as these and other factors change. Technicians must recognize where the heater's air supply is coming from, and how it is being supplied. Indoor installations and outdoor shelters must be provided with adequate air vents for combustion to ensure proper heater operation. To ensure these air supply needs are fulfilled, the confined space, where the heater is located, shall be provided with two (2) permanent openings (vents) communicating directly with the air supply: . one commencing within 12" of the top, and . one commencing within 12" of the bottom. See the Sources of Air Supply section above along with Tables A, B, and C for determining vent sizes. Also, remember to factor in (add) the air supply needs for any other gas appliances in the same room or enclosure. Air supply openings must be unrestricted, but can utilize permanently opened veins or louvers like those in an attic gable. However, if using louvered panels for air supply openings, the total surface area of the louvers and panel frame must be subtracted when determining actual air supply. (Example: A 7 Ox I 0 louvered panel does NOT provide 100 inches of free area for air supply, but approximately 52 - 56 sq. in.) Most vent manufacturers will provide the "unobstructed free area" for their products.


Propane Gas Usage

Liquid propane is externally compact and portable, but must vaporize to be released as a gas that can be used to fuel your heater. An insufficient gas supply causes reduced efficiency and poor combustion, which leads to soothing.

As a rule of thumb, Propane tank size should be 100 gallons for every 100,00 btu of heater rating.

If you're buying a Propane gas heater, the following information will help you decide how big a propane tank to select.

The rate at which a liquid propane converts to vaporized Propane gas is determined by many factors including: Humidity, Ambient Temperature, Surface Area of the liquid in the Propane tank. The "Rule of Thumb" for factoring these variables is to assume that a heater's Propane tank should be refilled when 60% of it's full-tank capacity has been used.

(BTU per hour - with 60 % Liquid in Tank)

Propane's ability to vaporize decreases with the temperature - particularly as the temperature dips below 60 o/F. On the other-hand, when the temperature outside is warm, say 85 o/F and the Propane tank has been 60% depleted, it will continue to provide sufficient gas flow for a while.

However, as the thermometer dips below 60 o/F, a Propane tank's ability to produce vaporized gas decreases sharply. In fact, as the chart above indicates, a Propane tank will yield barely HALF as much capacity at 20 o/F as it does at 60 o/F.

Also, keep in mind that cooler overnight temperatures can have lingering effect during the following day, causing the tank to not supply sufficient gas to the heater. "Low gas" conditions like these should be avoided, as they result in sporadic, inefficient operation.

Calculating a Propane heater's operating time

A single gallon of Propane will produce 91,000 British Thermal Unit (BTUs) in an hour. This fact coupled with the 60% usable rule of thumb allows anyone to determine how long a propane tank will supply enough gas to properly run a heater.

Calculating a Propane heater's operating time involves three-step formula illustrated below - though we should emphasize that these shortcut calculations are general in nature. The accompanying shortcut calculation are quite convenient, but are not foolproof method for estimating when a heater's Propane tank needs to be refilled. The safes method to use is the 60% rule of thumb.

AS propane tank is used or emptied, the tank contents steadily shift from liquid state to vaporized gas, reaching a point at which the remaining liquid propane no longer vaporizes enough to supply the proper amount of gas to the heater or appliance.

Calculating how long a full-tank of Propane will last

- Multiply the Propane tank's capacity by 0.6 (this is the "usable" Propane available with a full tank)

Step 1: Usable Propane = Propane tank capacity X 0.6

- Divide the heater's BTU rating by 91,000 (this is the gallons of Propane used in an hour)

Step 2: Propane Needed / Hour = BTU Rating / 91,000

- Divide "Usable Propane" (step 1) by heater's per hour gas demand (step 2)

Step 3: Hours of Operation = Usable Propane / Propane Needed per hour

The result estimates how many hours of operation can be expected for a specific BTU rating heater using a specific Propane tank size.

Hayward Heater Technical Information

GAS PIPE SIZING

Hayward heaters use a full gas fire design. To ensure adequate gas firing and proper performance, the following guidelines should be used to size gas piping.

1. Make sure the 1 st and 2nd stage regulators are large enough to handle the BTU I isted for each model.
2. Reduction of the gas supply pipe or tubing to the inlet of the valve must be made at the valve only - Natural or Propane.
3. Do not use flexible connectors on any gas connections.
4. If more than one appliance is installed on the gas line, contact your local gas company or Hayward for proper pipe size.
5. If you have any question concerning the installation of the proper gas line size, call Hayward before you install the line.

Low Pressure Natural Gas Pipe Sizing (Pipe or Tubing):

"Single Stage" Low Pressure Propane Pipe Sizing:

It is VERY IMPORTANT, when installing a Hayward Full Fired propane heater on a two (2) stage regulation system, to follow the gas line sizing chart below - without exception.

"First Stage" High Pressure Propane Gas Pipe Sizing:

"Second Stage" Low Pressure Propane Gas Pipe Sizing: