This Texas school has two conventional buildings, each with 20 air conditioning units along its back wall. That’s 40 units for just one tax-supported school! What does it cost to install and run 40 ac units in hot, humid Texas? Also, consider that this is a school for less than 300 students. Cost to cool your building It depicts the back side of one of two buildings that function as a traditional Texas school serving 236 students in Kindergarten through Grade 12. Like many traditional schools, this building has a line of 20 air conditioning units along its back wall. The companion building has another 20 units along its back wall. That’s 40 AC units at just one school! Consider what it costs to install 20 units. How much electrical do those 20 units require? How much just plain expense does it take to install and run 20 units? And these units are not inexpensive toys. They are not $100 window units. By the time the unit is installed, each costs a minimum of $3,000 to $4,000.

And bigger units cost two to four times that much. The next time you drive through town, please think about this. Look at the schools, look at the churches and just do a rough count of the AC units you see. split unit air conditioner vs window air conditionerKeep in mind that most schools and churches hide their units along the building’s back side.coleman furnace parts list As I drive through the suburbs of Dallas, I’m constantly stunned by the number of AC units I see at schools. how much is a fan motor for ac unitMany have one major AC unit for each classroom. That costs serious money – not only to install but to hook up, to maintain, to replace and most of all to furnish with power. It’s no wonder that we receive so much acclamation for our Monolithic Domes.

Our domes use one fourth that amount of air conditioning. Most conventional churches and schools in Texas use one ton of air conditioning for each 250 square feet. The rule of thumb for a Monolithic church or school is one ton of air conditioning for each 1,000 square feet. That’s 1/4 as much! It takes a lot of money to heat and cool buildings such as the one pictured here – especially to cool them in Texas where, in some years, we have more than 100 days of 100 plus degrees. ​are faltering​ and ocean temperatures are rising​. As this climate change trend continues and the Islands get hotter, focus once again turns to installing air conditioning in classrooms. HIDOE is not against installing AC — in 2015 there are 17 AC-related projects on Oahu alone being installed, from a new school (Hookele Elementary in Kapolei) to a new classroom building at Ewa Elementary to a series of building retrofittings. As funding is released by the state for these projects, we will continue to whittle away our lengthy project list.

However, our goal is to make all classrooms thermally comfortable in a sustainable fashion — using fact-based, data-driven methodologies that lead to effective solutions. Here are the challenges we face in addressing classroom cooling. Challenge 1: Our Budget The estimated cost of installing air conditioning and related infrastructure improvements at the schools that don’t have campus-wide AC was determined by using both the estimated and actual cost (where available) of recent projects and includes both design and construction costs.For example, the cost of air conditioning and related infrastructure upgrades at Pohakea Elementary School was $4.3 million when bids opened for the project in 2010. That equals about $110,000/classroom. Pohakea is one of our smaller elementary schools with an enrollment of 573 students in 2014. By comparison, August Ahrens in Waipahu, which is one of our largest elementary schools, has over 1,400 students. Based on this actual bid result, accounting for inflation since 2010, and adjusting for the various school sizes, we have estimated that the cost to air condition the average elementary school is $5 million.

The cost estimates for both middle and high schools were calculated in a similar fashion across the number and type of schools that need cooling. Total = $1.695 billion (Note: Combination elementary/intermediate schools were classified as middle schools; combination elementary/high schools were classified as high schools. We do have a cost estimate for Campbell High from 2010 which came in at over $13 million.)HIDOE has been piloting newer technology that could bring down the costs. Of the most promising is photovoltaic air conditioning (PV/AC). A portable classroom at Waianae High School is into its second year running a system using three PV panels for each air conditioning unit. However, there are limitations to how widespread PV/AC may be deployed — it's not a good fit for many multi-story buildings, and new funds will be needed to lease/purchase and install them. HIDOE's Facilities office is analyzing how many more could be added to our schools.​We are also running pilots around portable classrooms with

There are more upfront costs in the materials and construction related to standard portables, but can save more in the long run thanks to "grid free" energy production and use. Challenge 2: Infrastructure/Electrical SystemsThe majority of Hawaii’s schools are more than 50 years old. As a result, many buildings do not have adequate electrical capacity to accommodate the increasing use of electronics including computers, and other high demand infrastructure such as air conditioning. HIDOE tackles a number of projects every year to upgrade the electrical supply and infrastructure at various schools. Because of the age of many of our schools, their electrical systems reflect a bygone era — they weren't designed to support today's high level of energy demand, requiring major upgrades. In many neighborhoods, even the supply from the utility is inadequate. An elementary school recently bought air conditioners without the proper electrical upgrades and blew a circuit.

Electricians, electrical engineers and knowledgeable contractors will tell you it is important to ensure you have the correct infrastructure before adding more than the system can handle. Challenge 3: Building Improvements Just as our older schools were not built to meet current levels of electrical use, the buildings were also not designed to be airtight. This stems from the fact that it was important for air to move through the buildings in a naturally ventilated environment. However, for an air conditioning system to function effectively, the building envelope needs to be sealed, requiring replacement of windows (typically jalousies) and doors, among other things.​ While the initial cost of the air conditioning itself is substantial, there are other continuing costs to operate the system that must be taken into account. Factor 1: Cost of ElectricityEven if you don’t factor in the cost of the units and installation there is the cost that air conditioning adds to the Department’s electricity bill.

When AC was installed at Pohakea Elementary School, the power bill more than doubled. Currently, the Department is expected to face an electricity bill of $47.6 million this year.​ The chart below shows ongoing costs of all HIDOE utilities, including electricity; we have a number of initiatives that encourage reducing and softening our usage and that keeps costs relatively flat. However, year-over-year funding of utilities from the Legislature is dropping. That makes it that difficult to run the utilities we have, let alone add to the bill.There are some promising technologies that we have mentioned that can help reduce the cost of our electricity bill. Photovoltaic air conditioning draws most of its power for use from the PV panels. Some systems can be purchased with batteries. Those system are being considered, but there are some potential concerns regarding hazardous materials. HIDOE Facilities representatives have held discussions with several local PV companies to look at a pilot project for PV/AC with batteries.