Replysounds like you have it already figured out, short line set is good and the eastside is also good...I might rethink the Nordyne system but thats my personal opinion
Regular Guest
We are in the process of building a new home in Georgetown, KY (~1300 CDD 4600 HDD). The cooling days number is a bit misleading due tothe high summer humidity. We will have a 4 ton Maytag heat pump system with variable speed blower, zone control system and ERV. The house is ~2600 sq ft 1st floor ranch on 2600 sq ft full basement + 700sq 2nd floor. The rear of the house is full of windows (low-e) with a covered porch that will shade 90% of them from summer sun. Rear faces almost due south, probably about 190 degrees SSW. All walls will be brick and closed cell foam.
My question is regarding the outdoor unit placement.
We originally wanted to put it on the west side of the house just to the south of the garage doors. From a sound standpoint this was the best option, it would be next to the master closet and bathroom. This location would get full sun from about 1pm - sunset. It is also about 70 feet from the air handler. Our HVAC installer was going to upsize the line set to compensate for the distance.
Option 2: Place the unit on the east wall. Will get sun from sunrise - 1pm. We can place the unit on the wall outside the kids bathrooms. Will be 20' from the closest windows (only 2 on that side of the house anyway). I've been told the Maytag unit is very quiet and with the full brick and foam, I think sound is less of a concern now. This would be <20 feet from the air handler.
What are the thoughts out there? Will the line set length really impact performance/efficiency? What about heating vs cooling days? What side is the best?
Thanks.
Professional Member
sounds like you have it already figured out, short line set is good and the eastside is also good...I might rethink the Nordyne system but thats my personal opinion
Professional Member
I agree with Air but would also add a dehumidifier.
God Speed, Jim. We'll miss you - 2-26-23
The shorter run is better.
Increasing line set size on HPs should be avoided as much as possible.
Regular Guest
Thanks for the quick replies. The Nordyne/Maytag unit is the 15/16SEER line and appears to be a decent model. The warranty is the best I've seen. Have you had a bad experience?
I'm hoping that the variable speed air handler along with the 2 stage compressor will help with the moisture removal during the summers. I think they are installing a "Maytag" branded zone control unit and thermostats. I have specified dehumidification control as part of the package.
Sounds like the east side is the way to go.
God Speed, Jim. We'll miss you - 2-26-23
Haven't heard anything bad about the Maytag, except ypu have to put a tarp over them when planes fly over, so as not to blind the pilots.
Regular Guest
I was hoping that the Maytag VS airhandler would run slow enough (with dehumidify signal from thermostats...) and the compressor would run in 1st stage so that I could get enough water out of the air without over cooling the house.Originally Posted by Daltex
God Speed, Jim. We'll miss you - 2-26-23
If the unit is sized right, very good chance you won't need a dehumidifier.
I would have the system installed without one. You can always install one later if you need it. But if your house is reasonably tight, you shouldn't need one.
Regular Guest
The house should be tight, we are taking every step to make it that way. Manual J called for 4.2 tons, not taking into account the zoning system that our installer says will more than make up the .2 difference. I guess at this point it is wait and see. Once the duct work install is finished I'll post some pictures, maybe we'll even make it on the wall of pride
God Speed, Jim. We'll miss you - 2-26-23
If your going to keep the zones at different temps, it can make up for it.
EG: Bedrooms not kept as cool as teh other zone/zones in the middle of the day.
Regular Guest
Exactly.. We have 700 sq ft on the 2nd floor that will be basically a guest suite zone, not used too often. The other zones are master bed/bath, 2 kids beds/bath, main living area, basement (just to keep it moderately regulated).
God Speed, Jim. We'll miss you - 2-26-23
As long as your installer knows how to install and set up a zone system, you should be find. Small zones can be a problem even for 2 stage.
Is your basement finnished?
Regular Guest
Basement will be unfinished to start, but probably done is 18 months. Will end up around 2000 ft finished. Front 75% is poured concrete walls with R-5 on the outside. Back wall is 6" studs with closed cell foam. 170 sq ft of glass on the back wall (2 pane low-e argon) facing south.
God Speed, Jim. We'll miss you - 2-26-23
Ok, if it wasn't going to be finnished. I was going to suggest using it as a dump zone. But that won't work for a finnished basement.
Regular Guest
My understanding of the plan is to use a bypass damper back to the return duct and the zone controller will slow down the blower when only 1 zone is calling.
God Speed, Jim. We'll miss you - 2-26-23
Even in first stage, you can only slow the blower so much before the coil will freeze, or the zone systems anti freeze protection shuts the A/C off.
You system in first stage is roughly 80% of full capacity. So a overly small zone will require a large amount of bypass air, cooling the coil more yet.
If you have a zone that is only say, 12,000 BTUs at design temps(or 25% of system total capacity). thats about 800CFM of bypass in first stage.
There are zoning systems that are designed with that in mind, and also help to prevent short cycling from one zone calling 5 minutes after another zone is satisfied.
Regular Guest
I'm pretty sure they are using the Nordyne panel with a supply temp sensor and some sort of "modudamper" that controls the bypass based on the blower speed and zones calling.
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