Phoenix Manufacturing, MasterCool and Aerocool: An Owner and Buyer Guide

Phoenix Manufacturing is an evaporative cooler manufacturer based in Phoenix, Arizona, one of the hottest and driest large metro areas in the US and one of the biggest evaporative cooling markets. Its best known residential lines are MasterCool, built around rigid media, and Aerocool, which covers conventional aspen pad coolers. If you own one, the key to easy service is knowing which line you have, because the media and some cabinet parts are completely different between them.

This guide covers the company and its products in general terms. For the wider market see our evaporative cooler brands overview, and for budgets see what a swamp cooler costs.

What Phoenix Manufacturing is known for

The company is associated with whole-house coolers designed for desert conditions, where coolers run long hours from spring through fall and face hard water, dust storms and summer monsoon humidity. Two things set its lineup apart:

• A dedicated rigid media line. MasterCool has long been one of the familiar names in rigid media residential coolers in the Southwest, offering higher saturation efficiency than aspen.
• A full conventional line. Aerocool coolers follow the traditional aspen pad design that most DIYers and cooler techs already know.

Product names, sizes and features change over time, so treat the descriptions below as general categories and confirm specifics with current literature for the model you are considering.

MasterCool vs Aerocool: the two main families

The physics behind those numbers is explained in our guides to wet bulb temperature and aspen vs rigid media.

Construction details that matter in service

Cabinets

Traditional Phoenix Manufacturing coolers use galvanized steel cabinets, and steel pans will eventually corrode where water sits and minerals build up. Some models may use protective coatings or non-steel components in key areas; check the specification sheet for the specific model rather than assuming. Whatever the material, bleed-off, regular cleaning and complete winter draining are what extend cabinet life. See cabinet rust and pan repair.

Rigid media fit and orientation

Rigid media is made of cross-fluted sheets, and the flutes are angled to channel water down the face while air passes through. Installing a panel upside down or reversed can push water out the air-leaving face, causing drips into the duct and carryover. A panel that is short by even a fraction of an inch leaves a gap where hot, dry air bypasses the media. When you replace media:

1. Measure the old panels. Record height, width and depth, and photograph the flute direction before removal.
2. Order by model. Give the dealer the model and serial number, not just the measurements.
3. Check the distribution. Clean the distribution header or pad on top of the media so water spreads evenly across the full width.
4. Run the pump alone first. After installation, run the pump for 5 to 10 minutes and confirm the entire face wets evenly with no spray or drips on the dry side.

Our pad replacement guide covers both aspen and rigid media.

Water distribution

Aspen units typically use a spider or distributor with tubes to each pad trough. Rigid media units generally feed a header across the top of the media. Both clog with scale and debris, and a partially clogged header is a classic cause of a dry vertical stripe in rigid media. See the water distribution system guide.

Parts availability and cross-compatibility

Phoenix Manufacturing coolers are common in the Southwest, and parts support is generally easiest in Arizona and neighboring states. Elsewhere, you may rely more on dealers and mail order.

For the generic side, see the universal replacement parts guide, choosing a replacement pump and choosing a replacement motor.

How to find the model and serial number

1. Shut off power at the disconnect before opening panels.
2. Look for the identification label on the cabinet, commonly on a side panel, near the electrical box, or on the inside of the cabinet behind a pad frame or media access panel.
3. Photograph the full label including model, serial, voltage and amperage. Serial numbers often encode production period, which helps when a part changed mid-run.
4. Record the motor and pump labels too. If the cabinet label is unreadable, those let you buy replacements by specification.
5. Measure if needed. With no label, record cabinet height, width and depth, media or pad sizes, and discharge opening size for the parts counter.

What to check when buying or servicing

• Size first. Get a target airflow from the cooler size calculator, then shortlist models by rated CFM.
• Water quality plan. Rigid media lasts longest with adequate bleed-off. If your water is very hard, read bleed-off and water quality before you buy.
• Configuration. Match down-draft or side-draft to your duct. See down-draft vs side-draft coolers.
• Roof load. Larger rigid media coolers with a full reservoir are heavy; have an installer confirm the roof structure and stand.
• Spring check on a used unit. Look for scale crust on the media face, sagging panels, rust-through in the pan, and dry streaks when the pump runs.

Warranty considerations

Manufacturers commonly apply different terms to the cabinet, the motor and other components, and terms change between product years. Check the current warranty with Phoenix Manufacturing or your dealer before you buy, and keep the receipt and installer invoice. Ask whether the warranty requires installation by a licensed contractor in your area, whether labor is included, and how corrosion claims are evaluated. If your cooler is still under warranty, call before swapping in a generic part.

How to choose between MasterCool, Aerocool and other brands

A practical rule: if your summer wet bulb depression is regularly 30 F or more (check your city in the climate index), rigid media's extra efficiency is worth several degrees at the register. If you are in a milder or more humid area, the cheaper aspen option gives up less.