Boulder Architect Cherie GoffIn this 3-part blog series, Cherie breaks sustainable design into three steps. The first covers reducing energy use through Passive Heating and Cooling, the second covers options with Mechanical Systems, and the third covers Indoor Air Quality, Water Efficiency and Sustainable Materials.

Mechanical Heating and Cooling:

After we have design the home with passive heating and cooling systems, the next step in creating a low energy use home is selecting and designing mechanical heating and cooling systems that meet your energy goals and fit your lifestyle. Though passive design, the amount of heating and cooling should be greatly reduced, which in turn means you will need a smaller mechanical system. A smaller mechanical system is a win win – it will require less upfront cost, as well as less energy to run. Here are systems to consider, and ways to keep them as energy efficient as possible.

  • HVAC:

    Traditional forced heat and air can be designed to be much more energy efficient then in the past. An efficient system that does not have oversized equiptment and that looses as little heat and cooling as possible goes a long way. Here are some basic ways of increase the energy efficiency of forced heat and air:

      • Selecting energy efficient furnaces, hot water heaters and condition units
      • Sealing duct (and testing for leaks)
      • Efficient duct layout and design (oversized ducts and bad layouts reduce efficiency).
      • Insulating ducts or locating ducts in conditioned space to reduce heat loss or gain.
      • Adding a heat exchanger or heat recovery ventilation – which exchanges heat between incoming fresh air and outbound air. This not only save energy but also improves the indoor air quality.


  • Hydronic radiant heat:

    Radiant heat is a great option for many of our clients. It improves energy efficiency by reducing thermal stratification and provides improved comfort. In addition, it can be tied into a solar hot water system.

  • PV panels:

    We install PV panels on most of the homes we design. With current governmental and excel energy rebates, PV panels can be quite affordable and greatly reduce the energy use from the grid.

  • Solar hot water:

    We have found that solar hot water is best utilized if it can be tied into a radiant heat system. If the choice is between solar hot water and PV panels, PV panels typically win out because they have the better return on investment.

  • Evaporative cooling:

    Evaporative cooling has come a long way. In Colorado we have many low humidity days and this could be a good option.

  • Non-ducted air conditioning units:

    These are often combined with an evaporative cooling system to provide the extra cooling needed on very hot or humid days. You may remember these as wall units but they can also be integrated into the ceiling are architecture. They are energy efficient because the homeowner can cool one area at a time rather then the whole house.

  • Ground Source Heat Pumps (GSHP):

    These take advantage of geothermal temperatures to provide energy efficient heating and cooling. GSHP require some energy to operate so it is good to pair with PV panels.

  • Whole house heat fan:

    These can be used to quickly eliminate the heat built-up in your house by pulling cooler outside air in and flushing hot air out.

Green isn’t a buzzword. In our business practice and in our profession, sustainable design is a basic criteria. HMH advances sustainability as a requirement throughout the planning and design process on all of our projects. We firmly believe that saving energy and resources is not only good for the environment, but also good for business.

We promote an integrated approach to sustainable design; employing interdisciplinary team of engineers and designers to explore and evaluate potential green design opportunities from the earliest planning stages.