Choosing the Right HVAC System

All-too-many people focus on the heating and cooling system (HVAC) without putting first things first. We’d like to believe that we kept things in their proper order by first addressing the building envelope before deciding on the proper unit.

We had originally hoped to install a geothermal system to establish lifetime low maintenance and operating costs. However, our small lot, steep slopes and heavy tree canopy all served to thwart horizontal fields for necessary underground coils. The option to drill wells for coils proved cost prohibitive. Therefore, we turned our attention to creating the best overall fit for our site.

Calculating – Not Guessing – About Unit Size
With proper framing techniques, the best insulation and top-of-the-line windows – “Creating an Energy Efficient Envelope” – we then turned our attention to the proper HVAC system. We opted for all-electric split-system heat pump (even before the run-up in natural gas prices in the winter of 05/06) because all other appliances and our on-demand water heater would be electric. Our electrical engineering and construction advisors completed a “Manual J” (Air Conditioning Contractors Association of America) calculation to determine need. As a result, and with a zone control, we were able to go with a single three-ton HVAC system versus traditional recommendations for two two-and-one-half ton units of cooling capacity.

Amana – The Right Choice
We opted for Amana – one of the best known names in HVAC – now owned by Goodman Manufacturing (http://www.goodmanmfg.com/). We looked first at the then-current code requirements for a 10-SEER (Standard Energy Efficiency Ratio) system. With units now being manufactured with SEER ratings of 18 or more, we scoped the spectrum of efficency versus cost and arrived at a 14-SEER as the optimum decision. As the project took six months longer than originally planned, code requirements as of January 2006 required 13-SEER systems. Thus, our original plan still proved appropriate. The 14-SEER Amana also has an ultra-high rating for heating capacity of 8.5 HSPF (Heating Seasonal Performance Rating). HSPF ratings range from 7.0-9.4.

Easy Facts
For a great resource on how to go about choosing the right HVAC for your project, see http://www.southface.org/web/resources&services/publications/factsheets/1heat_cool.pdf

Using the Power of the Sun

We tried to use the power of natural lighting and take advantage of sun-power wherever possible. In addition to the therapeutic gains from natural lighting already mentioned – “Attacking SAD With Lights On” – we worked to take full advantage of the sun’s energy.

Passive Heating
We re-oriented the footprint of the house to align the aspect so as to “manage” the sun. The orientation means that the largest “face” of the house is oriented toward the sun. The extra wide overhangs will serve to block the hot afternoon summer sun when it sits at a high summer angle but will let the light in during winter months when it rides a lower angle. Even though we have high-efficiency thermal windows, the natural sun that penetrates in the winter will help warm floors and other surfaces.

Solar Water Heating
Traditional Hot Water Heaters are Full-time Energy WastersThe traditional 30- or 50-gallon hot water heater is always on. Whether you need hot water only for your morning shower or even when you head to the beach for a week and don’t need any at all … your hot water heater is steadfast about its task of heating and re-heating that water should you ask for it. It’s that full-time 24/7 heating that accounts for one of the most easily identified sources of wasted energy and added cost in the average home. We knew we could do better.

We added a 50-gallon passive solar panel on the roof (www.solarcart.com). Water “pre-heated” by the solar system will then go directly to a whole house “on-demand” water heater manufactured by Eemax, Inc.(www.eemax.com) Doing away with the traditional hot water heater means that we’ll only use electricity to heat water when we need it, not 24 hours/day, as is true with traditional systems. Additionally, the pre-heated water coming from the solar system means that the on-demand unit will have limited work to do to bring the water to the desired temperature.

Stopping Allergies at Their Source

Nothing has gotten more attention in recent years than the emergence of mold and mildew as major -- and costly -- problems in schools, offices and homes. Like most of their fungal relatives, these unwanted guests must have favorable conditions to thrive, among them moisture and a food source. Needless to say our humid southern climate provides a hospitable start. But, we don't have to put out the welcome mat.

As the costs of treating "sick" homes and offices grows along with the plethora of lawsuits against builders, it is imperative that new construction minimize the potential for mold and mildew growth. In Upstate House we've taken a number of steps to ensure that we haven't invited these unwelcome pests.

First, by semi-conditioning the basement and attic, we've eliminated major potential problem areas. Next, the super tight spary-in foam insulation further provides a tight envelop by limiting unwanted air/moisture infiltration.

In our case, because allergies have long been a personal problem, we took additional steps. We've gone with solid floors throughout and thus eliminated carpet -- another major allergy factory. And, we sprayed the most likely spots (under sinks and in bathrooms) with a non-toxic product guaranteed to retard growth of mold and mildew. That product, FortiCel, was applied by Building Environmental Solutions, Inc. -- www.buildingenvironmentalsolutions.com

So, we've limited many of the factors that would lead to problems. Yet, if you've ever had a leak through the roof or a small flood from a busted pipe, you know that your drywall, once wet, often sprouts a chronic crop of mold or mildew. The only option is to rip out the affected areas and replace them with fresh board. This can be very disruptive and costly. Enter, GP's DensArmor Plus. DensArmor is a totally new generation of drywall that replaces the paper face of the wallboard (the food source that supports growth of mold or mildew) with a glass mat that provides superior mold/mildew resistance -- www.densarmorplus.com

Since mold and mildew can grow on just about any material, and under a wide range of conditions, it isn't possible to totally eliminate it. However, we think that by semi-conditioning the basement and attic, by going with DensArmor wallboard and by judiciously applying FortiCel in other high-risk areas, we've taken adequate precautions to ensure that our new house will indeed be a healthy home.