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General => General Forum => Topic started by: n74tg on May 21, 2008, 08:30:29 AM

Title: HVAC Concept Discussion
Post by: n74tg on May 21, 2008, 08:30:29 AM
I don't know if this is the right forum to begin this discussion in.  So, moderators, if you need to, feel free to move it to where you think it belongs.

Like many of you, I too am building my own place.  Glenn's "AC Spacepak" topic made my thinking take a detour down a different road for a while.  I am very worried about the future cost of energy, specifically natural gas for heating, and electricity for cooling (and heating). 

Right now, I am leaning toward central air and heat in the house being built, but I've begun wondering if we get some future significant cost increases in energy, that trying to heat and cool the whole house may become cost prohibitive.  If that happens, then a lot less costly alternative will be to NOT heat and cool the whole house.  In my mind, with a central hvac system closing vents won't make the system run any cheaper (that could possibly be a bad assumption).

So, maybe to begin this discussion I will ask a question or two.

Let's assume that we are in for significant and possibly prohibitive cost increases in the energy that we use to heat and cool our homes.  What do each of you think about merits and demerits of individual room heating and cooling; ie window units, and/or other individual room heating and cooling methods?

 

Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 21, 2008, 08:41:20 AM
We already do that in our house in the Valley where temps go near 100 for much of the summer. 
Title: Re: HVAC Concept Discussion
Post by: ScottA on May 21, 2008, 08:50:22 AM
I think window units are more cost effective for cooling so long as you remember to turn off the ones not in use. Also window units will have a lower upfront cost. If you are in a humid climate removing moisture from the air maybe more important than cooling it. An A/C that's just barely big enough will be more effective at removing humidity. As for heat you should look at the best fuel source. For us it's wood which we can harvest for very little cost in $$$. Unless your place is pretty large having more than one wood stove doesn't make much sense. If wood isn't an option I'd look at some sort of radiant heating which you can zone off. Fuel would depend on your local. If oil runs low electricity may be a better option long term. Regardless a smaller well insulated home that is designed to use the sun to it's advantage will save the most money in the long run IMO.
Title: Re: HVAC Concept Discussion
Post by: CREATIVE1 on May 21, 2008, 02:51:50 PM
One of my clients is involved with this company which provides solar air conditioning..   $$$$, but the website has lots of technical information.

www.solarsa.com
Title: Re: HVAC Concept Discussion
Post by: MountainDon on May 21, 2008, 04:20:39 PM
One of the problems I have with window A/C's is their noise level. The other is it seems more difficult to direct the air flow so it doesn't blow directly on me. Maybe I'm a nit picker.  :( 
Title: Re: HVAC Concept Discussion
Post by: John Raabe on May 21, 2008, 08:21:49 PM
Make sure the design, insulation levels, passive ventilation, landscaping and lot placement are all working in your favor first. These are the free and near free energy choices that will work for the life of the house. Then, zoning the heating and cooling makes a lot of sense. As costs go too high you can retreat into a more core area of the house and let the other areas serve as buffers.

My long term guess is that electricity will be the lower cost fuel of the future. Using small heat pump units for zoned heating and AC should be a good choice in most mixed climates.
Title: Re: HVAC Concept Discussion
Post by: MountainDon on May 21, 2008, 09:34:58 PM
Quote from: John Raabe on May 21, 2008, 08:21:49 PM

My long term guess is that electricity will be the lower cost fuel of the future.

I agree completely. All the more reason to invest in solar PV or maybe wind generation depending on where you are. I really think more people should consider a grid tie system, with net metering, over being totally off grid. My reasoning is that grid tie obviates the need for an expensive battery bank and their maintenance. Grid tie net metering has your meter running backwards when your system produces more than you are using at that time. Then you can draw from the grid when your demands exceed production. With proper system sizing you can average your use and generation out over a year to the point where you owe the power company for very few KwH worth of electricity.

Making electricity is easier than making fuels to burn.
Title: Re: HVAC Concept Discussion
Post by: n74tg on May 21, 2008, 09:48:43 PM
Don:
I don't think Arkansas does net metering yet.  If memory serves, you can give power to the grid, but you don't get any credit for it.  Of course that could change in the future.
Title: Re: HVAC Concept Discussion
Post by: MountainDon on May 21, 2008, 10:09:47 PM
Dang! That sucks. Net metering is about as good as it gets... you get 1:1 credits for your generation, BUT with most systems you can NOT make money at it. Our local power company is typical as far as I can tell when it comes to power companies that do 'net metering". They do not pay you at all. Period. That's why I say size the system correctly so you make just about what you use, averaged over a year. The credits from one month carry forward and are applied against future bills, even months down the road.
Title: Re: HVAC Concept Discussion
Post by: Erin on May 22, 2008, 03:34:07 PM
Neither Nebraska nor Kansas buy power back, either...  :P
(I'm not sure about credit, though)

So far as room A/C--  Of the dozen homes I've lived in since childhood, only one had central A/C.  Even my folks' three-story Craftsman in muggy eastern Nebraska, has had nothing but window A/Cs.  (though in their wealthy middle age, they have more of them!  lol)

Like Don, my only real complaint with window units is the noise. 
In our current house (where our utilities are free for as they're a job perk w/ the house), we have three, samll window units.  On truly hot days, we'll have all three running and a couple of fans, too, to circulate.  Part of that though is the fact that this house is a ranch-style and wasn't built for proper circulation.  ::)

In the house we're building we're going to use either window A/Cs or a swamp cooler or two.  But even before that, we're doing as John suggests and building to gain the most from our environment (breeze, shading, insulation, etc)
Title: Re: HVAC Concept Discussion
Post by: MountainDon on May 22, 2008, 04:08:18 PM
Quote from: Erin on May 22, 2008, 03:34:07 PM
Neither Nebraska nor Kansas buy power back, either...  :P
(I'm not sure about credit, though)

Something made me go and check out the local power company regarding their latest solar power info. Lo & Behold! They have made a change for the good!!   :o

There is a program, under which they WILL pay you for all the excess power generated!! And not at some lowball 'avoided' cost rate. Currently they will pay 0.13 per KwH. That's better than even the highest rate we'll be paying, even with the increase that's coming very soon. (Rates are tiered in three steps,  up to 200 KwH a month, 201-700, and 701+, escalating as your use bumps from one to the next.)

The only catches are, your equipment must meet their standards and you must pay a $100 application fee. Otherwise even if you overproduce you will not be paid. Still, a fair enough deal.

Part of the reason for this will be that it helps them meet their legally mandated alternative power generation quotas.
Title: Re: HVAC Concept Discussion
Post by: n74tg on May 23, 2008, 11:09:56 PM
Well, well, well.  After rereading the net metering posts (thanks Don and others) I did a little research tonite and in fact Entergy Arkansas DOES offer net metering.  So far they won't pay you cash if you overproduce, but they will carry your overproduction credits forward for future use. 
 
So, looks like I will be looking into solar pv more, AND after reading all the posts on users who do not have central ac, I may just go that way too.  Sure would make building this house easier.
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 24, 2008, 09:12:51 AM
If planning to us window units ahead of time you can make a dedicated opening in the wall for the unit rather than wasting  window space.  Foam crack filler bars can be used to seal it or as a filler for caulking.  A power plug can be placed inside or out as needed and units can be had that have heat also.  The one pictured is a heat pump unit -- don't waste your time and money on it.  Get the standard room A/C - heat unit.

(https://i35.photobucket.com/albums/d184/glennkangiser/wallac.jpg)

Title: Re: HVAC Concept Discussion
Post by: JRR on May 24, 2008, 10:37:11 AM
Nice looking room!

I agree with the concept of a special/dedicated wall opening for a room ac unit.  "Everything else being equal"; a location near the floor, and near the center of the wall, might be better for noise concerns.  Furniture, tables, rugs, etc ... will all help to muffle the noise.

Of course, a "split unit" would even be better.  Does any USA retailer sell them?
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 24, 2008, 10:55:38 AM
Thanks, JRR.  That is at our conventional house in the valley - 75 miles away.  That was the remodel of the old house I did for Sassy.

My concern there was mostly the A/C and getting the cool air to mix with the warmer air, missing the furniture and having a straight shot toward the kitchen through the archway.

(https://i35.photobucket.com/albums/d184/glennkangiser/kitchentolivingroom.jpg)

Title: Re: HVAC Concept Discussion
Post by: n74tg on May 24, 2008, 05:20:12 PM
Glenn:
Did you build the "conventional" house too?  About how big is it, number of rooms, and number of window units.
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 24, 2008, 07:01:52 PM
It was built in 1952 by a preacher - pretty fair construction - no insulation.  We had the early foam insulation foamed in in 1980 or so.

I remodeled it a bit at that time too and added on a 2 story addition in roughly the shape of a water tower which was a common structure in our area.  I added a extra bathroom and hallway between an existing bedroom and bathroom.  It is around 1700 sf total - about 25 x 50 plus the addition.

It has the kitchen/dining combo plus the living room, 4 bedrooms (1 used as an office) hall/bookshelf library, 2 walkin closets, bath and a half, utility room and enclosed porch, with a small foyer at the front door between the living room and dining room.  We have 2 player piano's there and a built in wall shelf.

(https://i35.photobucket.com/albums/d184/glennkangiser/piano.jpg)

(https://i35.photobucket.com/albums/d184/glennkangiser/shelf.jpg)

We have one window unit in the master bedroom/bath/walkin closet section and the other shown in the living room/kitchen side of the house.  We also have a small wall mounted A/C in each of the addition rooms. The one remaining bed room is used for storage and is excessively hot in the summer.  The heat pump freezes up soon after it is started and does not heat in the winter.  The combo unit in the master bedroom is pretty good. 

The house is heated with a Toyo oil heater in the winter - about 120 gallons diesel per year.

(http://www.toyotomiusa.com/products/laserventedheaters/images/L-60ATa.gif)

http://www.toyotomiusa.com/products/laserventedheaters/L-60AT.mv

Title: Re: HVAC Concept Discussion
Post by: FrankInWI on May 25, 2008, 10:30:59 PM
just bought LP water heater, it was a clearance, and floor model, and I got 10% more off by taking out credit card. 
After I left with it, and sent it up to our dacha with my sons, I wondered why the heck I bought an LP one.  Seems like gas / electric prices diferential is changing, and it's easier to turn off and turn back on electric for the weeks we're not up there.
oh well.... now to decide on heater for the upper (have LP garage heater for lower).  Seen the Toyo you have glenn, and wonder about the practicality of getting fuel oil these days. 
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 26, 2008, 02:59:25 AM
We just use diesel but the cost is going up.  It's easy for Sassy to use though.  It's pretty high tech and about 98%? efficient recovering even most of the exhaust heat.
Title: Re: HVAC Concept Discussion
Post by: mvk on May 26, 2008, 07:37:18 PM
Glen
Nice looking place, not bad for a chainsaw and adz, but how did you get the Bobcat out ;)
Mike
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 26, 2008, 10:45:44 PM
Sorry you had to see that, Mike.  It was before I realized I was an earthdweller.

Can't imagine living in a place like that anymore, but Sassy has to go there every other week to work.
Title: Re: HVAC Concept Discussion
Post by: Dilly on May 27, 2008, 04:07:45 PM
I am not certain how you buy diesel in the states but in Canada you can use farm diesel which is a lot less.My farm buds have been using farm diesel in their trucks for years.  Just don't get caught but for home use maybe you can by a tank or put a pumper at one of your farm friends and go over and fill your Jerry cans once every week or so.  Just a thought.
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 28, 2008, 12:42:30 AM
I have equipment so have a red diesel card.  About a buck cheaper here I think- regular diesel was $5.19 today.
Title: Re: HVAC Concept Discussion
Post by: Dilly on May 28, 2008, 06:28:04 AM
Your price of diesel and ours is getting closer. We are running at 1.27 a liter which is about 5.65 an imperial gallon which equates to about the same. Our regular gas is just about the same price. I have an suv so it gets scary.  I am not travelling far these days. Travelling in Ontario which is a long drive anywhere is down about 30% after our holiday weekend.
Title: Re: HVAC Concept Discussion
Post by: peternap on May 28, 2008, 07:13:44 AM
I have central heat/AC in my burb house.  I haven't used the AC in 10 years. It's a lot chwaper to use window units. The noise doesn't bother me (too many years shooting without hearing protection :-[)

Glenn, I looked at your remodel......I hate you! :)
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 28, 2008, 09:22:26 AM
Thanks, Peter.  I think I now have myself successfully under control. [crz]
Title: Re: HVAC Concept Discussion
Post by: Okie_Bob on May 29, 2008, 08:23:10 AM
You had me worried there Glenn, I go away for a week and come back to pics I couldn't believe I was seeing! Glad to know you have things back under control!! (BTW caught a bunch of rainbow's up in New Mexico last week, 10,000' up in the cold mountains!)

I HATE window A/C units and find them extremely expensive to operate. Seem very inefficient, noisy and impossible to control mixing of air. Mine was built into the wall of the garage apt I built to live in while building the house over the past 5 years. HATE IT.

I totally agree with Don about solar PV and net metering as the solution long term. Glenn walked me through his off-grid system and it just seems too expensive with the battery bank plus the maintenance required. Much cheaper to eliminate the batteries  and use the grid for those times you can't generate your own power.
Largest cost to do this are the PV panels. BUT, there are several companies that claim to have new technologies about to be introduced that will drastically lower the PV cost. IF that happens, everyone should get on the bandwagon and at least put up PV for hot water, I would think???? Check out www.heliovolt.net and look at Ramala University in Israel for two of the newer players.
John's point is especially important. You need to decide very early on about all the environmental factors regarding location of your proposed building site. Once built, it's usually too late. Sometimes there is nothing you can do about it but, exploring it in advance can make a huge difference.
I went with open cell foam envelop, an 18 SEER A/C electric heat pump, variable speed, two stage compressor and electric operated duct for seasonal zoning. Expensive to install but, hope it pays for itself soon. Also suggest set back thermostats.
Okie Bob
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on May 29, 2008, 11:23:03 AM
Sorry, BoB.  I promise I'll never do it again. [crz]

Paint - sheetrock -- plastic-- they're for other people - not troglodytes. d*
Title: Re: HVAC Concept Discussion
Post by: peternap on May 30, 2008, 08:06:58 PM
Bob, Ascent Solar has a true flex panel in limited production now. It should be available to the general public in 2010 and the projected cost should be a dollar a watt.
Title: Re: HVAC Concept Discussion
Post by: Okie_Bob on June 02, 2008, 08:09:18 AM
Peter, if they can produce a high quality panel at $1 per watt, we can all go solar. Current prices I have seen are $5/W and if you figure even 2KW you are looking at $2,000 vs $10,000 per application. Why wouldn't someone want to go solar at those prices?
Okie Bob
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on June 02, 2008, 10:23:38 AM
If it gets into that good of production and comes down to that price, demand will be so great, supply will likely raise the price to near the $5.00 in 2 years anyway - that and the declining dollar. 

In 2010 a panel that would be $1.00 will likely cost $2.00 due to the decline, but I see demand for the low cost panel driving the price to near the existing price anyway. 

This is a global market now and I don't see anyway one company could supply the demand of the world for low cost solar panels.

Just my opinion.  Please tell me I'm wrong.  I want some. :)
Title: Re: HVAC Concept Discussion
Post by: MountainDon on June 05, 2008, 11:52:28 PM
Quote from: Okie_Bob on May 29, 2008, 08:23:10 AM
(BTW caught a bunch of rainbow's up in New Mexico last week, 10,000' up in the cold mountains!)

Where'd you go Bob??

It snowed up at 8800 ft this AM at our place.
Title: Re: HVAC Concept Discussion
Post by: MountainDon on June 06, 2008, 12:01:03 AM
Quote from: glenn kangiser on June 02, 2008, 10:23:38 AM
Just my opinion.  Please tell me I'm wrong.  I want some. :)
You're wrong. There.  ;D   Feel better?   ;D

If one company can do it, so can others. That's the way I see it. The price of 'regular' PV panels has done nothing but drop over the past 5 years that I've followed; there have been momentary peaks, but the prices have fallen overall. [Sorta like the prices of the Model T over its years of production.] And that is with increasing world wide demand.

Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on June 06, 2008, 01:04:00 AM
Declining dollar should keep the price up though. [crz]

At that price the waiting list will be so long we won't be able to get them.  What's the cheapest you've seen lately - we may want some. :)
Title: Re: HVAC Concept Discussion
Post by: Okie_Bob on June 06, 2008, 07:17:57 AM
Sorry Don, just now saw your question. We went up next to the Philmont Boy Scout Camp...it's called the Express UU Rance, 160,000 acres and 10,000 head of cattle. Two weeks ago today it snowed pretty good as I was catching some rainbows and we had pretty heave ice on the vehicles the next morning before we left. One of the most beautiful places on earth. And so far our in the boondocks there was no cell phone service, no tv, not even radio where we were..nothing and not a sound that wasn't natural. God what a place!!

Glenn, I hope you are wrong on this one. If enough mfgr's start making the lower cost panels, maybe the prices will stay low? I'm probably just being the optimist here. But, at $1/watt, I'm going totally solar just as quick as I can get the material.
Okie Bob
Title: Re: HVAC Concept Discussion
Post by: glenn kangiser on June 06, 2008, 09:59:24 AM
I'd really like to see it, but I can't see them leaving that much money on the table for one thing.

The drop to low pricing will have to happen over a long time as in computer technology.  There will likely be patents the others will have to work around.  I don't see anybody giving away the technology unless it' an individual.

If China happens to get the technology and ignore the patents that could change things.  Likely an American company will take the work over there to be done anyway unless it is a totally automated process where they do not need employees so that could cut the time it will take to get the cost down.

You have to remember that this will start to put some competition to the oil companies at that price also.  They won't want that to happen unless they have a major piece of the pie.  That will either raise the price or stop the project.

...but just guessing from the way I see things. [crz]