Good Afternoon all,
I have gathered up 3 quotes in my local area regarding the Actron ESP Ultima setup. The quotes seem to vary in price by around $2000 and in different zone setups. Controllers etc. But I’m trying to get my head around what will be the better installation because one quote has all bedrooms zoned but I’m sceptical that there will be far too much pressure on some of these rooms due to the small size.
I understand that the 17.5kw Single Phase Actron ESP Ultima has a minimum zone duct pressure of 185 Litres per second. What I would like to know is what pressure rating the duct work can withstand for 8inch and 10inch ductwork. I found reference from Google that 8 inch Duct can hold between 50 - 90 Litres per second and the 10 inch Duct 90 - 160 Litres per second but unsure how credible these figures are and would like to ask any installers on Homeone if these values are roughly correct?
Some quotes are referring to a common zone that will always be on but from what I gather as long a zone has enough ducting to support the minimum airflow of 185 L/s each zone should be able to run independently without the need for a common zone. Having a common zone defies the whole point to me of installing the ESP ULTIMA is this correct?
I have a few rooms in question which I think will possibly be too much for the ductwork. I have an example below of my study from the quote which states an 8 inch duct.
Its 3.9 meters X 3 Meters which equals 11.7 SQM, from what I can gather to get KW ratings needed for rough air con cooling is to multiply the SQM by between .125 and .150. Ill use the higher end (11.7 * .150 = 1.755KW) this is roughly the power needed to cool the single room. I also found reference on Google that around 60 Litres of air a second is needed per KW of cooling. Some quick maths on 1.755KW * 60 = 105.3 Litres per second of air to effectively cool a room of that size, this pressure appears to be over the duct rating of an 8 inch duct and under the minimum pressure rating for a single zone on the ESP Ultima. 1) Would this amount of pressure be likely to blow the duct apart or create substantial problems with noise and other issues in the future? 2)Should this room be zoned with my theatre room that will have a 10inch duct allowing over the minimum 185 Litres a second?
If the pressure figures I have been using for 8 inch ducts are correct and they can withstand a maximum of 90 Litres per Second and zoning 2 bedrooms together with 8 inch ducts = 180 Litres per second would this be borderline enough to run a single zone on since the ESP Ultima's minimum fan speed is 185 Litres per second or would the extra 5 litres per second be negligible?
I would like to stress I’m no expert and my formulas are most probably incorrect. I just would like to see if I’m on the right wave length and get the best out of my install!! It’s a big outlay.
Cheers and sorry for the long winded post
Steve