Question Category: Testing

Question: Twinned furnaces I have 2 80,000 btu/3ton blower twinned. Measuring static and calculating is this actually supposed to be a 6 ton blower? when measuring we found that tesp was the same through both totaling .1 Other job, separated systems with common return. static is ok when only one system running. when both are running static goes off the charts to 1.2 or 1.5 How do we calculate for Heat/coolmax.

Question Category: Air Flow

Question: It seems to me one could determine airflow CFM with a pitot tube and anemometer if we took enough readings to get a representative average. That is what a traverse measurement is, correct? Of course the location in the air flow changes the value. By the same token does not changing the location of the static pressure tube in the air flow also give you different values and should we not also take several readings to get a representative average?

Question Category: HeatMaxx & CoolMaxx

Question: On the CoolMaxx report, section 1 system pressures where exactly do we measure the 2 pressures to add to obtain a total staic pressure?

Question Category: Static pressure

Question: When refering to fan rated pressure either from a manufacturers chart or the generic table is this for the total static pressure from behaind the fan (I always refer to a direction of from return to supply) to after the furnace element, before the coil or the total system from before the return register to after the supply register? Or what?

Question Category: HeatMaxx & CoolMaxx

Question: Can we determine duct leakage based on the values in the CoolMaxx report, if so how?

Question Category: Heating

Question: Do you have anything in writing I can share with my customer about High Low fire or staged equipment?

Question Category: Test Instruments

Question: I'm thinking of buying a TSI flow hood. It seems that it will read up to 2000 cfm, but I will be reading values much lower than this that may total 2000 cfm. How accurate is it when reading individual 4" to 9" supply ducts that are no where near the high range? Is it more accurate as the volume of air increases or is uniform accuracy across all volumes? I have read where some lose accuracy at low volume levels. I just want to trust my measurements if I fork out that kind of dough.

Question Category: Air Flow

Question: I recently finished servicing a montgomery ward furnace model # SRM54-4345B 80 BTU. The blower had not been cleaned ever. My before static pressure readings were return .016 supply .041 after cleaning the S.P. were return .042, supply .095. here is my question. The before and after delta T remained at 70 degrees. I expected the temp. difference to drop by some amount say 5 degrees? If I'm moving more air across the heat exchanger why did the temp. reading stay the same? Is this usually the case?