Hot water heater timer update

Wolfy:

As Ray mentioned, the biggest drawback to geothermal heat pumps - even if you are in BFE and never have to worry about disturbing neighbors by digging up your yard - is that probably 50% of them are *never* installed properly.

As geothermal heat pumps are *very* expensive to install, they had *better* be as cheap as borscht to operate. The only way to achieve that efficiency is to make sure the heat transfer loop is as warm as possible for heating and as cool as possible for cooling.

So usually the deeper the better.

A friend of mine in Ontario had to build a new house 6 years ago when his old one got zapped by lightning and burnt to the ground. He went geothermal but insisted on digging the heat transfer loop hole himself. This was summer so he was able to borrow a skidder off a nearby logger who was laid off.

He went down 25 ft, put the loops in, backfilled with some sand, put 3 inch styrofoam on top, then backfilled the ground the rest of the way. Since he's a mile from his nearest neigbour, this was easy to do.

Oh, the heat pump "expert" and him got in to a *constant* pi***** match over why that wasn't necessary. It was a huge PITA. But this January, his monthly electric bill was only $140, which for Ontario Hydro is amazingly low.

FWIW this "expert" also put in a heat pump system 5 miles from my friend, done the way the "expert" thought it should be done. It barely works at -20 F, with the supplemental electric resistance heat constantly needed below that temp. Monthly electric bills on an Equal Payment Plan of $380, the same that person had with baseboard electric heat before investing $14,000 for the "efficient" geothermal heat pump.

The geothermal "expert" has since gone out of business and moved away. So if my friend needs the system serviced he is SOL. That tale alone turned me off using geothermal heat pump for my hobby farm, the installation is just too finicky to trust the average crackpot "expert."

You'll be using air-to-air heat pump? That should be able to heat down to 32 F, though depending on conditions you may need supplemental electric resistance heat sooner.

Given your climate, I would think the separate zoned systems would work best for a 2 story house, with improved efficiency. Usually, a 2 story house has different heating and cooling demands: for cooling, it's harder to cool the second story; for heating, it's harder to heat the first story.

For a single system you need zoning controls - a giant finicky PITA - and a system dramatically oversized to meet the heating and cooling needs of both floors. I don't suppose a de-superheater will work with an air-to-air heat pump, will it??

Some tips:

-make d*** sure the ductwork is sealed *and* insulated. This will *dramatically* improve the performance and efficiency of the system.

-The more insulation in your attic, the better. R-50 is better than R-40, and R-60 is even better than R-40. Price it out. You'll have a hot attic from your climate, even if the roof is properly vented.

-Continuous roof peak venting works far better than a few vents here and there. Not sure what your home will have, I have continuous venting on mine to eliminate ice dams in the valleys and edges.

-Low-e films are of different quality. Use the proper heat-rejecting film for South and West windows.

-Have you priced tri-panes? Up here they cost around 20% more than dual panes. With low-e treatments and Argon fill, they offer remarkable performance and make the home quieter too.

-If your cooling needs are primarily for just one area, say a large master bedroom on the 2nd floor, consider a separate wall unit or ductless system instead of overcooling the entire house for your personal comfort. Your cooling season is far longer than your heating season, this is an important consideration.

Some good reading for you:

http://ducts.lbl.gov

http://www.mrslim.com

Hope this helps. Remember it's the little things that make a *huge* difference in how much energy your new home will use. Things like windows and attic insulation are easy to change before the foundation is poured. Once you wait until you're in the house, it becomes an $$$ PITA to fix.

 

wolfman-
Two units can work to your benefit if you operate them properly. Tract builders typically oversize their units. Having two smaller units allows you to run only one, which is more energy efficient and better at removing moisture from the air. In the winter, use the downstairs unit to do the whole house while circulating air with the upstairs unit and do the opposite in the summer. In peak demand times, both units can be utilized. SEER 14 is the best rating that you can get without the extra cost being unrecoverable in energy cost savings.

As far as recovering the cost of using two units on a two story house; I would need to know alot more about the house. I would need to see a manual J report, look over your plans, and study your epuipment specifications. Your lifestyle would have a bearing as well. My seat of the pants guess would be that energy savings might not be fully recovered but quality of life would be improved through more complete control of your living and sleeping environments. Go to this website and learn more about building science. http://www.buildingscience.com/

Finally, check into the DEC ultra aire UH150 dehumidifier. This unit will introduce fresh air into the house in a filtered and controlled manner, while removing excess moisture in the spring and fall. Typically the low cooling demand during these times of year leads to elevated humidity levels due to the reduced dehumidification associated with air conditioning. High humidity levels will contribute to increased levels of mold and dustmites.

Finally, in any new home, it is important to well ventilate for the first year, in order to reduce levels of contaminants from off-gassing of carpet, plywood, and finish materials.

 

That is heat reflective film and in hot climates it works wonders. Though it can reduce the life of shingles. It's a tradeoff.

SInce you prefer a cooler house, it makes sense to have a split system. There are good resources that Ray has mentioned. Will provide more myself later.

 

Wolfman-
Radiant barrier sheathing is very cost effective. On the website that I sent you to, you can learn about unvented attics. You will not be able to go that route with the typical production builder, but read up on it anyway. In the future, most houses in this climate will not have vented attics. Attic ventilation was developed in the north to prevent interior moisture from forming ice in the attic and ice dams on the roof. The studies that established the 1:300 rule for attic ventilation came out of Minnesota in 1939 and became a national building code in 1942. Tyvek was developed for very similar reasons. Both systems are inappropriate for hot humid climates. Your climate is actually quite different from mine even though we are 200 miles apart. You get abit more winter than we do but you would still do better without attic ventilation and spun polyolefin housewrap(Tyvek).

In an unvented attic the insulation is installed just under the roof deck and all the mechanical system is within the conditioned space. All energy losses from duct leakage etc. are then within the house and do not create negative air pressures. These negative pressures draw in outside air through leaks in the envelope. Unconditioned, humid, dusty, pollen laden air is introduced by this effect and leads to energy loss and poor indoor air quality. Ever wonder why you can dust your house and have a fresh layer of dust a few days later? That is caused by duct leakage in your vented attic. You payed to pump that dust into your house!

Unvented attics can be done at no additional upfront cost, but not by production builders. A few builders are currently working to develop these systems and work through the bugs. David Weekly, Pulte, and Centex are all experimenting with various forms of this system in limited markets. This system must be properly implemented in order to not lead to moisture problems in the winter.

The codes are slow to catch up and it is difficult to implement codes that are appropriate to various hygro-thermal regions, but we must. National building codes actually require the same building practices to be used in climates that are vastly different from the climate that they were developed for. South Florida, Las Vegas, Minnesota, Oregon, Gulf Coast, and Chicago are all under the same code but all have far different requirements. Simply requiring more insulation up north is inadequate to the task of differentiation. I have a little first hand knowledge of how difficult it is to modify the codes to different regions and implementing non-prescriptive codes seems to be a daunting task. So here we are, shaking our fist and recognizing the problem, without yet having a soluton that doesn't cause a new set of problems. I think I've gotten way off track so I will just hit the submit button.

 

Manual J is a load calculation that is used to size the AC system. It develops a complete breakdown of cooling and heating loads to assist in the placement of registers and prevent oversizing of the equipment. You can get a clear picture of where heat loss will occur in order to develop a strategy for heating and cooling.

The sizing you mentioned tells me you should spend the money. It will be rare that you will need 5 tons of cooling for this house if they do a halfway decent job with the building envelope. They size for peak load and then round up to avoid complaints. I cool my 4000 sq. ft with 3 tons and it doesn't run much even on a hundred degree day. You will be much happier with the two systems and when you get moved in we can do a little adjusting to improve things for you. More on that later.

Can I talk you out of the fireplace? From a building science standpoint, they suck. No, literally, the negative pressure developed by a fireplace will suck in cold outside air in the rest of the house. This phenomena is why a wood burning fireplace usually contributes zero net energy to the house. The rest of the year they negatively impact your air tightness. How about a chimenea on your porch? Fireplaces in this climate cost alot upfront and add a substantial amount to you electric bill year round.

 

Jayman-
You've done your homework. Let me disagree on one point here though.

Shingle life reduction is overblown. Shingle temperatures on radiant barrier sheathing are increased by 5 degrees. Dark brown comp shingles heat up 40 degrees warmer than white comp shingles. That never seems to be mentioned. Most of the heat disapation from shingles happens in the form of radiation to the sky, not through the decking.

 

Hi Ray:

I did a bit more research on the shingle life issue. It was a problem up here around 10 years ago. Upon closer examination, it turned out a combination of factors caused curled and destroyed shingles here:

1. Lack of roof ventilation which caused ice dams on the edges and valleys.

2. Dark or black shingles with the radiant barrier was a definite no-no.

It's one h*** of a lot easier to build a house in a predictable climate, say one that never dips much below freezing. Up here, it can dip to -40 in winter. We've had summers with record-breaking 100 F, although usually 85-90 F max.

If I move back to Utah or Nevada, I wouldn't even bother with ductwork in the attic. I'd seal the attic - nonvented as you said - and use ductless ceiling mounted evaporators. For what little heat you need in a climate like St. George UT or Mesquite NV, baseboard electric units work fine and are cheap to put in.

Fresh air - controlled fresh air - is very important in any climate. When they first mandated the tight homes up here (Tyvec house wrap, etc) it created huge problems with interior moisture buildup and IAQ issues. No matter where you live, an HRV (Northern climate) or ERV (Warm climate) is a good investment.

 

The jury is still out on ERVs due to the high upfront cost. We use a large capacity dehumidifier for mechanical ventilation. The vest ERV that we have found is the Venmar with a 79% efficiency. Installed price is around 2000 USD. That's around 20,000 Kwh. That is enough to dehumidify my house for 40 years or so. If you want to have absolute control over humidity levels you will still need a dehumidifier. The ERV simply reduces the amount of sensible and latent load added by ventilation. It's a great product but pricey. By contrast, in the north, a good HRV is about a third the cost and the pay off is around 5 years.

 

By the way Jayman-
How did you get so interested in these subjects?

 

Well, because I've learned the hard way, by having 10 new homes in the past 16 years, that most general contractors, HVAC installers, electricians, etc etc can't be trusted. I'm not saying most of them are a** holes out to rip you off: most of them are just uninformed and too stubborn to change.

Fortunately, I never lost money on any of the homes I've had. Though on some I've only had break-even. It seems I only find out about the more serious problems long after the ink dries.

So I've had to do a lot of research on my own, ask a lot of questions, and try to figure out the best way to do things. This is reflected in my newest house that I had built at the hobby farm. It has turned out the best, though there is always room for improvement:

1. The HRV intake vent hood, despite being 6 ft above finished grade, will still ice up at 0 F or colder. Doesn't appear to be any practical solution except for some sort of electric defroster in the vent hood.

2. The cement sidewalk from the garage to the house has settled 2 inches in the past 1.5 years. I wanted to put SM Styrofoam along the edge to block frost/ice and heaving, but the cement guy said it wasn't necessary. Bulls*** now I have to do it all over again.

3. The Bryant Evolution Plus 90i is sensitive to power fluctuations and the entire Evolution control network will latch up if power quality is very bad. Will have to look at hard-wired surge suppression and power filtering from APC or Tripp Lite.

The sad thing is, when it comes to homes, the vast majority of home owners are simply not in a position to be able to afford to fix something once they discover it is royally f***** up. I, on the other hand. can afford to plunk serious change but deeply resent doing so.

I tend to blame myself for not knowing more about home construction. So I snoop around - if that's what you want to call it - ask a lot of questions, and demand answers.

And despite the fact 9 homes ago I swore upon my own grave that I would *never* get involved in another home ever again, I'm already thinking about the next one. So I'm already taking notes of all the pitfalls and caveats I've learned to apply to the next one.

Maybe I just like punishment. I suppose I'm some sort of hidden S&M freak when it comes to homes. I'm a Systems Analyst, not a GC. Though I recently purchased a Paslode gas-powered framing gun.

 

Wolfy - I'm with Ray on this one. A regular fireplace is incredibly inefficient. Also, with homes being built ever tighter, they can even become dangerous due to back-drafting.

How about a direct-vent natural gas fireplace? I have one in my high-rise condo and it given the illusion of flames while being clean and relatively efficient. That bugger really throws the BTU's too: the cat loves to stretch out on a pillow in front of it.

Or how about a direct-vent airtight wood fireplace insert? In this case you have a "real" flame but it's efficient as all the combustion air is drawn from outside. I have had them in the past and they work well.

http://www.regency-fire.com/Wood/Inserts

About the only advantage to a wood-burning appliance of any sort is that if the power is off for a long period of time, you can still heat your home and do some cooking. I think that's more of a concern if you live in BFE.

Don't get me wrong, I didn't mind firing up my Husqvarna 61, slicing up some trees, and chopping firewood. It's d*** good exercise for one thing. And it's also good to learn how to sharpen a chainsaw too. But you'll never catch me touching a chainsaw ever again.

 

Nope.

Up here, a good high-capacity HRV with auto-defrost is around $2,500 Cdn and up. And that model needs electric core defrost, which really adds to the power bill.

My Bryant HRV with automatic dampers uses recirculation to defrost the core. This takes longer but is *far* more energy efficient than electric defrost. I have the model with Evolution control networking at the hobby farm, it set me back around $3,200 Cdn.

 

Whoa, that is really pricey. I was talking about one that is good for 60 cfm. What kind of capacity are you using? Is this for the kitchen vent hood? How do you handle make-up air for that and what about the grease. Oh wow I just looked at the topic of this thread. hehehe

Your environment is a truly hostile thing to overcome in building residential construction. That's why some og the best building science comes from there.

 

Well, homes up here either have to have "central exhaust" (Kitchen, bathrooms, basement, laundry room) or a true HRV. The exhaust piping is the same whether central exhaust or HRV: the central exhaust blower then exhausts the air outside and a large insulated pipe allows fresh outside air to enter.

The HRV puts the exhaust air into the core, which also has the fresh outside air pass through. The two air streams never mix, but heat transfer occurs. It's a h*** of a lot more efficient than just having raw air dump into your house, especially in temps colder than 0 F.

I think this is my unit:

http://www.bryant.com/corp/details/0,1312,...ETI8706,00.html

It's rated for 169 CFM. A big reason for the higher price is the Evolution control network interface. The system uses logic to determine when the HRV should run, considering factors like outdoor temp, indoor humidity, heating or cooling mode, etc.

The kitchen stove exhaust hood is separate from the HRV. It's illegal to hook up a kitchen hood to an HRV. The HRV port in the kitchen also requires a mesh filter to meet code.

Although my kitchen stove hood is vented directly outside, I still have a charcoal filter on the hood itself. A lot of folks don't realize all that grease can be sucked up by the fan and put into the duct. Eventually you get a nasty fire.

The kitchen hood makeup air is made up from the HRV supply, as the HRV is self-balancing.

As far as the cost of an HRV up here, the cheapest model I've seen was around $900 Cdn for a tiny one. It would be ok for a small condo but not a typical bungalow.

 

A whole house fan!

It definitely won’t work in all areas, especially high humidity. If you live in a non-humid area and the temperatures cool off at night, a whole house fan a is a very smart investment. Mine paid for itself in less than two years

I installed one four years ago and now my summer electric bills are lower than my winter! (Akin to the Prius having better milage in the city than freeway). We rarely turn on the A/C.

In the Spring and Fall, I turn the whole house fan on in the heat of the day to warm the house. I then have no need for the central heater.

My brother just installed this model whole house fan. I am jealous as it is quieter than my Nutone Ultra-Quiet bath exhaust fan!