I have just installed a 9000 BTU Pioneer Mariner self-contained unit. It starts smoothly and runs well. My problem is that the unit produces too much cold air and noise, even on the lowest fan speed. I asked the supplier, Parker Davis in Miami, if it is possible to make the fan run slower than it's standard "slow" setting. They responded as follows:

"This means you do not have enough duct external static pressure. You may be using a very short air duct or no duct at all. Try to extend the duct length to create more external air static pressure on the blower.  Also use a heavier, thicker return air filter on your return air grill for creating more ESP on the return side as well. This also helps you to have much better air filtration, less noise and cleaner evaporator."

The delivery and return-air paths are short and smooth and the system already has a return-air screen. Adding extra ducting and a heavier screen will be difficult to do and anyway seems like poor engineering. Is it possible to slow down the fan?

Mike

Steve,

Many thanks for your prompt and detailed reply.

The circuit diagram confirms your assessment: the fan does indeed have a separate wire/winding for each fan speed. I shall leave the electrics well alone for fear of overheating.

My current ducting arrangement is as follows:
Output: 3" diameter blower nozzle feeds 4" PVC duct 18 inches long with 6" louver on end.
Return: 9" square louver mounted 3" from evaporator fins with fine mesh screen.

Removing the output ducting produced no discernable change in fan speed.

I think my options are (a) live with it, or (b) instal a branch in the output ducting and send part of the cold air into the next cabin.

Mike

Steve,

Ooops! my bad: nozzle is 4", same as the ducting. I really don't have space to increase to the next size up as the run of duct is so short.  I think my only option is to install a sweep-T in the outlet line and divert some of cold air into the saloon.

I tested the air-in and air-out temps after the system had been running for about 15 minutes. The differential was between 12 and 14 degrees (F). I believe this is in the "healthy" range. I held the infra-red thermometer about the same distance (3ft.) from the inlet and outlet louvers, not directly in the stream of the oulet air, and aimed at the center of each louver.  I made certain the compressor was still running. I this the right way to do the temperature measurements?

BTW. I tried to post a cople of small pictures. I can upload them, but I can't access the "browse" tab to select them.

Mike

Steve,

I believe the unit is working as it should. The three fan speeds can best be described a fast, faster and fastest. This is likely the main source of my problem. I should probably have shelled out the extra for a Crusiair unit, but that's history now.

I have decided to split the ducting between forward cabin and saloon. When this is complete I will post temperatures and, if possible, a couple of pictures. Thanks for your input and patience.

Mike