2015 - Higher Efficiency Water Heaters

[Mikesolar]

Originally Posted by SDMCF

I don't follow that, but maybe it is climate-dependent. Here, in winter, my attic could be over 50C colder than my house, so putting the water heater there would be crazy.

These are mostly in the southern US where there is often no basement and it doesn't get too cold. I personally think it is silly to have any mechanical equipment in an attic space unless it is within the building envelope (and then, only the cooling air handler).

[Servicetech]

Having a furnace/air handler in an attic costs more than going from 13 to 15 SEER would save.

[gasstingy]

Having your air handler and ductwork in the attic is not as energy efficient as running them in the crawl space, or should I say under the floor since all homes don't have a crawl space.

That said, attic air handler / ducts done right aren't that crippling of a liability. Because we did not want to have ducts in our floor, we put our ducts through the ceiling. Did it cost more? Maybe, I did not price putting them in the floor. What are the benefits? You don't have to arrange furniture to suit your floor registers, you don't have dirt and trash falling into your floor registers, you don't have to carefully fit your flooring materials around..... you get the idea.

We have put some effort into making our house energy efficient, and we had a home energy audit done June of last year. I was fortunate that the QA selection of my auditors work chose my home to verify his work. With our old gas furnace / 12 SEER AC unit we had a HERS score of 28. {We had the audit to verify sizing of a new, more energy efficient all electric unit.} With our new 19 SEER/10.2 HSPF unit installed and a bit more caulk and 10 more inches of attic insulation, the HERS score after the QA was 16. The old furnace and air handler as well as the new unit were/are mounted in the attic above my attached garage.

[Elwin]

"The Delegated Regulation enters into force on 26 September 2013 and the requirements will be strengthened gradually. Two years after the entry into force, a scale from G to A for conventional heaters (i.e. presumably G–D for electric boilers, C–B for non-condensing boilers in collective buildings, B–A for condensing boilers) with higher classes A+ for cogeneration and A++ for heat pumps will be introduced. Six years after the entry into force of the Delegated Regulation, a further class A+++ will be added on top of the labelling scale, while classes G to E will be abolished due to more ambitious ecodesign requirements. This will ensure dynamic market transformation toward highly efficient heaters using modern energy technologies." http://www.rehva.eu/publications-and...space-heaters/

With respect to the use of boilers, here in the Netherlands we mostly use condensing boilers although they are rapidly being replaced with heatpumps and geothermal, as well as solar boilers.

[Servicetech]

Originally Posted by gasstingy

Having your air handler and ductwork in the attic is not as energy efficient as running them in the crawl space, or should I say under the floor since all homes don't have a crawl space.

That said, attic air handler / ducts done right aren't that crippling of a liability. Because we did not want to have ducts in our floor, we put our ducts through the ceiling. Did it cost more? Maybe, I did not price putting them in the floor. What are the benefits? You don't have to arrange furniture to suit your floor registers, you don't have dirt and trash falling into your floor registers, you don't have to carefully fit your flooring materials around..... you get the idea.

We have put some effort into making our house energy efficient, and we had a home energy audit done June of last year. I was fortunate that the QA selection of my auditors work chose my home to verify his work. With our old gas furnace / 12 SEER AC unit we had a HERS score of 28. {We had the audit to verify sizing of a new, more energy efficient all electric unit.} With our new 19 SEER/10.2 HSPF unit installed and a bit more caulk and 10 more inches of attic insulation, the HERS score after the QA was 16. The old furnace and air handler as well as the new unit were/are mounted in the attic above my attached garage.

How many sqft per ton are you running on the super tight house?

[gasstingy]

Our heated sqft is 1519. The old unit was a bit oversized at 3.5 ton. The new unit is 2 tons. I was told when my energy auditor said I could go with 2 tons it would be a marginal fit. Then he added that if I would add 5" more insulation in the attic, it would be exactly right. So, I added 10" since insulation settles.

[Servicetech]

Why don't more people do the downsizing thing? Saves a LOT in energy costs.

[Mikesolar]

Originally Posted by Servicetech

Why don't more people do the downsizing thing? Saves a LOT in energy costs.

Simple, idiot installers never want to get a call back when the equipment cannot meet the heat/cooling load. Out utility is famous for doing this. Pisses me off to no end...

[oil pan 4]

Originally Posted by Mikesolar

The cost of a 90% + water heater doesn't make sense unless you can couple it with an air handler or floor heat and do the space heating. It must be used for more than just water heating and with lower heat load buildings it will be a good system.

I suspect that the min 13 seer AC will be replaced with a 15+ seer soon.

Whats SEER 15+ going to look like?
3 phase powered with solid state coolers pumping heat into a geothermal heat sink?

[Mikesolar]

Nothing weird. I put in an 5 ton 18 seer a few years ago and the only difference was a 2 stage compressor and control.