I have a new construction home. Based on some issues I've had from the start, I feel the system is unbalanced and needs one or more fixes.
This is rather drawn out, so please feel free to take on question or area and focus on that.
The HVAC company has been out 20+ times(NO, really - I have all of the invoices. Talk about a tremendous waste of my time!)
... Does anyone have any recommendations for HVAC repair in the future for the North Dallas area?
The front room(study/Bdrm 4), master bedroom, living room, and kitchen have been warmer by approx. the following(these are actually better than before the contractor made several 'fixes').
During the cooling months...
Study - 5-6 Deg.
Master bedroom - 3-5 Deg.
LR - 4-6 Deg.
Kitchen - 3-7 Deg.
The winter is here, and swings/variations are not as bad but I'm still seeing the same trend. The study seems to be affected to a lesser degree, but I believe that can be easily explained by the addition of a new home file server(As of November - Approx a 60W average heat-load).
There are few things I've thought of as possible solutions. I feel wasting my time with the HVAC company will prove frivolous - At this point they claim the variations are very normal, and they have zero obligation to make any corrections.
Possible solutions I've thought of include:
1 - Alter angle of supply box in attic to 45' from the current 90' bend in the 16" flexible duct coming off of plenum supply. Also would facilitate correcting angles/beds in most of the supply lines to registers at or near supply box.
2 - Return air; transfer air grille (Master? LR?)
3 - Ducting size changes in rooms. LR needs one more? Master needs one more; or even a Y?
4 - Perhaps one of the variable and constant on blower setups?(ECM or VS?) I've seen several options for installing a multi-speed blower - I'm very confident I could do this on my own given I have the right wiring diagrams in front of me.(IE, Emerson 5521ET). Or perhaps an IAQ with my current blower or a new blower?(Factory blower has 3 speeds, but low speed is still high for 'circulation' mode).
5 - Thermostat relocation? If I turn the fan on - The rooms seem to balance out fairly quickly. Perhaps the issue is the location. It's by the two rooms with the least amount of heat production. Only 2 windows, South facing wall.
6 - Zoning out the system? I have a strong electrical and mechanical background due to occuptation.... but I don't know enough for placement, location to put makeup air return, etc. Any thoughts based on my floor plan?
-Pictures provided do mark location of return, registers, duct sizing, and thermostat.
-All ducting is R6 Flex. Return is direct - no ducting, just a large non filtered register.
-Home has a central updraft style return in the hallway. Return grille in filtered;filter at handler.
-All doors left open 24/7 with two exceptions - Pantry & Master Closet. Doors also have a 3/4" undercut
-Insulation for problems rooms on outside walls has been inspected by 3rd party utilizing a thermal camera as well as a blower door test. Apparently, as far as air leaks go... my home exceeds Energy Star standards by 2-3 times.
-The supply box is currently level on a horizontal plane. All but one of the takeoffs are taking some rather harsh bends within a few feet or less of the box due to truss webbing and cords. Changing of the angle should allow the 16" return from Plenum to Box be more of a 45' then the 90' plus. It'd also allow more direct ducting to the other supply's from the box with fewer bends(or any at all).
-Contractor has modified the duct run to the study. Now it's 8" all the way to the study. They did a flip on the ducting for Dining and Study. Damper added to 8"run for Bedroom 2 and 3 - These two rooms receive little if any air right now, but they still stay in comfortable temperature ranges
Heat pump make/model: Lennox 14HPX-036-230-12
Air handler make/model: Lennox CBX26UH-037-230-1 (1/3hp 1.7 FLA 825 RPM motor; 37,000BTU)
Geographical loc: North Texas(North Dallas Area)
Filter size: 20x25x1
Fan rated CFM(set on Med): 1,354 CFM