Outdoor Reset v Setback Thermostats

For years the Department of Energy has promoted the programmable setback thermostat as a means of saving energy.  In 2005 several field studies by the Department of Energy determined that in most cases the introduction of a programmable thermostat didn’t conserve energy and in some cases actually increased usage.  The biggest problem they found was that the thermostats either were not programmed correctly or in some cases were not programmed  at all.

Now along comes outdoor reset which adjusts the water temperature based on the outdoor temperature in an attempt to match the heat loss.  When coupled with a programmable thermostat it can be a recipe for customer discomfort.  As the water temperature is reduced the BTU’s into the space are reduced as well since the heat loss is less, the goal is to only put into the space what is leaving.  However if a setback thermostat is in play and not only are we trying to match the heat loss but raise the space temperature 10 degrees it could take a few hours.  To combat this many thermostat manufacturers have added to logic in their thermostat to learn a systems response time and come on a few hours earlier.

If a customer is setting their thermostat back at night to save energy they are better off to just set it and forget it and allow outdoor reset to manage the system.  The long run time to heat the house back up will offset any energy savings.

Or take a look at the next step in the energy saving evolution indoor feedback, with indoor feedback a system can tailor the water temperature to the actual heat loss, synchronize the zones to eliminate short cycling and ramp the water temperature up for those times when it has been setback or turned off.

Article by George Carey about Indoor feedback
Tekmar House Controls

Altherma provides a Solution

A recent renovation on the Cape sent the HVAC contractor looking for a solution to a unique set of conditions, provide heating and cooling to a home that sets on the beach, without using a fossil fuel, not be affected by the salt air and fit in to the aesthetics of the house and surrounding area. 

Enter the Daikin Altherma Monobloc this all in one unit will provide heating and cooling with a SEER rating of up to 27 and a COP of 4.  The small footprint of the Altherma and its built in pump allow for an installation over 40' from the house and will be enclosed on 3 sides by a small structure to match the home.  And with Daikin's PE Fin the fins are covered with an acrylic and hydrophilic coat that has efficient corrosion resistance.

More reasons why Daikin is the world leader in Absolute Comfort. 

Energy Consumption in America?

Keeping people comfortable in their homes is what the HVAC industry is all about, when energy was cheap grossly oversized boilers operating at 70% and 8 SEER air conditioning systems with Ozone depleting refrigerants where the norm.  As energy prices increased higher efficiencies and SEER ratings have begun to take over the market.  However, the United States still wastes approximately 58% of its total energy consumption, according to the US Department of Energy.  In 2012 the United States is forecast to consume 99.46 Quadrillion [i]BTU’s of energy at an estimated overall efficiency of 42%.

The answer to energy waste in the US is not that simple since people still want to be comfortable in the homes, have plentiful hot water at the disposal and drive their car to the mall.  A lot has been said about the emerging renewable energy market yet it will produce a little over 2% of all the energy consumed in 2012. 

While we have a long way to go to eliminate the energy wasted in this country there are a few changes we all can make that can have a big impact on saving energy with little or no impact on comfort. 

1. Reduce the thermostat setting on your water heater by 10° to save between 3-5%.   While there is a very slight risk of promoting legionellae bacteria when hot water tanks are maintained at 120 degrees, this level is still considered safe for the majority of the population.[ii]
2. If you have an Indirect Water Heater lower your boiler setpoint by 10° this week if you still have sufficient hot water lower it again.
3. If you have an oil furnace check your nozzle size, many of these units have adjustable firing rates.  When my wife and I lived in Maine we changed the 1.00GPH nozzle for a .65GPH nozzle, the house heated fine the unit was much quieter and we reduced our oil consumption by 20%.
4. When setting up the outdoor reset curve on a hydronic system lower the top and bottom end down 10° below where you normally do and explain the benefits to your customer.
5. If you have a boiler without a reset control that is set to 180° drop the setting to 170°
6. If you haven’t already done so take Masssave up on their offer to audit your house and give you free energy efficient light bulbs, money toward insulating and weather responsive controls.
7. And if you’re a contractor next time you offer a high efficiency heating system don’t forget to offer an Indoor feedback system, which is basically automatic outdoor reset, that Masssave will pay about ½ the cost of the control.

For 2012 lets all find a way to be part of the energy consumption solution in America.

---

[i] U.S. Energy Information Administration

[ii] U.S. Department of Energy

BYE BYE Incandescent Light Bulbs

The Lighting Energy Efficiency portion of the Energy Independence and Security Act began phasing in January 1, 2012 this effectively bans the manufacturing and importing of 100 watt incandescent light bulbs.  In 2013 the ban will eliminate the 75 watt with the 60 and 40 watt being eliminated in 2014.  What does this mean to the typical consumer?  They have 4 options; stockpile all the incandescent bulbs you will need, switch to Halogen bulbs, CFL (compact fluorescent light) or LED.  Will this affect your wallet?

Based on the life expectancy, purchase and annual operating cost the 4 options match up like this:

Bulb Type	Unit Cost	Total Cost to own & operate
Incandescent	$0.62	$12.50
Halogen	$1.75	$10.58
CFL	$1.66	$2.95
LED	$19.78	$2.50

Interesting how the LED bulb that cost almost as much as 32 incandescent bulbs will actual cost less to purchase and operate over the course of a year and with a $10.00 a year savings the payback is 2 years. And in terms of payback the CFL is indeed the winner with a 1.25 month payback.

 

How can this help the HVAC industry?  As the consumer becomes more aware of looking in terms of higher upfront costs being offset by energy savings, it should hopefully make the conversation easier when discussing High Efficiency Heating and Cooling equipment. 

ARE DEGREE DAYS IMPORTANT

Absolutely, they can really make the difference in calculating your return on investment.  Let’s take a quick look at how this October with the unseasonably warm weather, could impact our perceived savings not only historically but in the future. By using my house as an example, which has a single pipe steam system with a standard efficiency boiler we can see the weather related impact.  Last October we used 82 therms for heating and hot water production, this year that dropped to 50 therms or a reduction in use of 39%.  Since I did not make an efficiency upgrades these savings are strictly weather related.  Now let’s look at my usage factoring in degree days, last October we had 271 degree days vs. 157 days this year.  So my usage last year was .30 therms per degree day and this year .31 therms which is actually an increase.  If next year the weather pattern is the same as 2010 some customers who have made high efficiency upgrades may actually see an increase in the fuel usage, so it is important when discussing energy savings to base it on degree days.

ICFs emerge as building blocks of sustainable construction

Take a look at this interesting article on a house built with Insulated Concrete Forms.Read the full article.

Fuel Savings Analysis Calculator

NORA-Oilheat has a fairly simple to use fuel savings calculator available to download from their website। You can use this to compare the cost savings of several different heating systems at one time।

Click Here to Download