New guy in East TX

[dablack]

Hey Guys,

I've been reading the site on and off for a while now. Found this place via ecomodders. I found ecomodders because I'm interested in migh MPG.

Anyway, two years ago we moved out of Houston when my NASA job fell out from under me. Now we are in central east TX and are building on 30 acres. We plan on a garden, chickens, guineas, and maybe goats later. Also putting in an orchard behind the house and using grey water and roof collection. Right now the house is framed and I'm in the middle of the DWV side of plumbing. I've built the entire house myself. 1 1/2 story about 2400 sqft. It has taken me less than a year to get to this point. I've got the front of the house point solar south and the roof pitch is 12:12. I don't know the ideal angle of solar but that has to be pretty close. Anyway, I'm going to be putting in some extra plugs that will later be hooked up to solar. We are literally at the end of the line for power so I won't be surprised if we lose power in storms. We keep lots of food on hand so I need to keep the fridge and freezer running. I'm thinking they will be the first to go on solar.

thanks for a great site. I'm going to go post about the above sheething ventilation roof that I'm putting on.

Austin

[Daox]

Welcome to the site Austin! Looks like a great project you have going on there. We'd love to hear anything you are willing to share I'm sure. There is LOTS you can do if you start from scratch. We'd love to hear what you have designed/done, and other things planned as well as the solar PV stuff.

[Xringer]

Hi Austin,
When that NASA job disappeared, you should have moved to the NSA, they're growing like crazy..

Anyways, here's the best site to use for PV angle finding..
UO SRML: Sun chart program

It gives you a nice printable chart output..

Here's what mine looks like..


I've got quite a bit of swing (north of Boston)..
So, I've made my elevation angle adjustable. I'll have to make a new chart,
if I ever move back home to Texas..

[dablack]

Thanks for the link. It looks like for a fixed mount, a 30 degree slope would have been better than a 45 for me. Oh well. My chart goes from 35 degrees of solar elevation in Dec to 85 degrees Jun 21. Is there a rule of thumb percent loss for ever degree off from perpendicular? I'm sure there is, I just don't know it.

NSA? Uh......I'm sure they are a great outfit to work for but we had been trying to get back to east TX and buy some land for years. We really didn't want to raise our four kids in Houston. I found a great engineering/manufacturing facility in the heart of east TX. I'm pleased.

[Xringer]

I forget how high the sun can get down there in the summer. (Left home in 1963).
When I was kid in Del Rio, 'east Texas' was anything east of Uvalde (like Hondo).
I did spend some time on a farm near Prairie Dell. Off the east side of 35. Nice flat area..


30 deg looks like the better of the two choices.

If there is a season when you will need more power during the day time,
(like boiling hot summers) you might want to favor the appropriate seasonal angle.

Here's another link for you.
It's a pretty good site for solar stuff. They get into a lot of systems detail.
Some of it's too much for me. I just want to set-n-ferget.
Panel Angles


Here's a pic of me in the backyard..
http://i46.photobucket.com/albums/f1...solarfarm2.jpg
I'm doing an experiment, called "Where in the world, is the worse place to mount PV?"..


For good cooling (and heating), inverter type mini-splits are only way to go.
Check them out at Geothermal & Heat Pumps - EcoRenovator
I've been having pretty good luck with a couple of old Sanyos..

[dablack]

Thanks for the link. I will take a look tonight.

I actually looked at minisplits but the house is pretty big and two stories. It was going to cost a pretty penny. Then the wife's little sister got married to an AC installer.....In TX, there aren't many guys that know much about minisplits. My new brother in law installs traditional systems and can get me a deal on a 4 ton system. He will also install it. Too good of a deal to even look at minisplits.

I'm in the part of east TX that is crazy hilly. Lots of iron ore deposits and steep hills around Rusk. Around 1900, a little town called New Birmingham sprang up about 1/2 mile from my property. If you are looking for intersting TX history....

[Xringer]

Wow! I just skimmed New Birmingham, Texas - Wikipedia, the free encyclopedia
and it's amazing! Never heard of it before.
Nice pictures. That doesn't look anything like the Texas that I know..

Those ' traditional systems' use a lot of power compared to Inverter mini-splits.
Anybody who has installed AC equipment can easily install inverter mini-splits.
Even I can do it, and I have zero HVAC training. (But I can read manuals)..

If you install a roof load of PV, in the 3 to 4 kW range and your home has some good insulation,
it's very possible you could cool(or heat) your home without using grid power (when it's sunny).

It's 80F outside today and our Sanyos are idling along at 0.7 kW per hour.

Our computer gear and the Plasma TV are using almost that much right now!

My old Sanyos can provide cooling on pretty low power..
http://i46.photobucket.com/albums/f1...L/poweruse.jpg
Check the power ranges at the top of the chart..

Here's heating info.
http://i46.photobucket.com/albums/f1...CL/heatcap.jpg
On a mild winter day, one 24k Sanyo can do 36k of heating. 3 tons..

[dablack]

Yes, that is why I was looking at minisplits in the first place. I know I can install them. The problem is, the cost. From what I remember, you can have one out door unit (condenser) and up to four indoor units. Right? But upstairs we are going to have three bedrooms, two bathrooms, and a laundry room. Lets say we have a unit in each bedroom and a unit downstairs (one big open room). How will the cool air get to the bathrooms and laundry room. Are the units big enough to cool 2500 sqft? Then if they are big enough to cool that, are they still energy efficient and how much would they cost?

I'm not afraid of AC systems and have built the whole house myself. When I restored a 71 F100, I put a modern AC system in it and made all the lines myself, pulled the vac and filled it up. No big deal. In the middle of Houston, in traffic, behind a ford 460 engine, that cab was COLD!

thanks
Austin

[MN Renovator]

Minisplits come in all sorts of sizes, find some model numbers of multi-zone units and then go to AHRI Certification Directory, scroll down the list to find variable speed mini-split and multi-split heat pumps and you can compare the efficiency ratings.

Smaller single head mini-splits will get you the best efficiency and larger ones and multi-split units a little bit less efficiency but it is still very good for what you are getting.

Since you built the house, you know how well insulated it is, it would be a good idea to do a load calculation to know the required BTU output so you can properly size the unit for cooling. If you are going to use it for heat, you'll want to make some decisions there regarding sizing to accommodate that too. In my case I want to size for cooling and use a smaller unit than what could heat my house in an extremely cold Minnesota winter but I plan to keep my natural gas furnace anyway and natural gas is extremely cheap where I live in comparison to even the most efficient mini-splits and the balance point on cost is around the freezing point, oddly enough that is also roughly the point where the unit is running full capacity on heating too so if I use it for heating, I would still be in decent shape for sizing. I'm also undersizing my mini-split consideration with plans to use the central air that I already have if it ever gets too hot but I'm also planning on putting in 90% solar blocking screen over my large sun facing windows through the summer and I think that will make a 12k mini-split into the appropriate size for my house and weather conditions in my area for nearly any temperature. I learned from the 6th Manual J book that I found cheap on ebay to calculate everything and I've done a whole bunch of going through the latest manual J book at the reference only(can't check it out) section of the main branch of the library in my county to be sure that my heating needs could be met with the smallest furnace I can install but I'm not willing to heat with a mini-split getting that cold, too many compromises to the size of system I'd need to install and the detriment to cooling EER and SEER in the summer.

[jeff5may]

Austin,

The main question is: What do you like and how much control do you want to have? This will help you determine what's best for your house. You and your family will be living in it, so you might as well think about it for a while. Each type of system has its own merits and disadvantages, so after some research is done, you will gravitate towards one or the other pretty quickly.

I assume you have a good idea of central ducted HVAC systems and their virtues. Unless you are planning to install a home automation system and zone controls, these pretty much deliver air to everywhere you might want it, how and when you want it. Performance comes from having a highly competent (ace) contractor do the inital design/install. The energy savings comes from:

1. a well-insulated and balanced duct system
2. zone control, either manual(at each vent) or automatic(expensive)
3. a high efficiency, multi-speed outdoor unit (expensive-r)

In contrast, a multi-mini-split unit like you are considering usually has an infinitely variable (inverter) compressor built in that uses only the amount of energy your zones command. Some have programmable, hard-wired controls as an option, but most are simply adjusted at each zone as needed. The indoor units have a decent amount of throw, so they do a much better job than a typical window shaker unit, and can be strategically placed to condition adjacent zones when doors or vents are opened. Performance comes from doing your homework up front, both in choosing a unit that will fulfill your needs and carefully considering indoor units' placement.

It sounds as if you are already leaning towards a central, ducted system. Make sure and pick a unit that will satisfy your demands (including free hot water), there are literally thousands to choose from! Above all, ensure the ductwork is well insulated and sealed before enclosure. These two steps wil pay for themselves over and over again.