Friday, February 13, 2009

My Future Resort (p3.3) - Heat and AC

According to the report I mentioned before regarding home electricity use, heating is about 10% of the bill, AC is about 16% of the bill, and water heating is about 9% of the bill. That's a lot of money! Now how do we bring those costs down?

If you're still in the planning stages, it's the best time to start thinking about heating and cooling costs. Good design can go a really long way in reducing these costs! If your buildings are already in place, consider some of these options when it's time to remodel (or sooner if it's cost-effective).

Heating / Cooling technologies and ideas for hot / cold places:
  • Passive solar: If a roof has the right overhang and window placement, it will let in light during the winter months and block light during the summer months.
  • Thermal mass: Better for hot days and cold nights, a thermal mass will keep the temperatures average by absorbing heat during the day and emitting it during the night.
  • Landscaping: Plants such as trees and vines have a unique and useful feature -- they grow leaves to soak up all the sunlight during the summer and drop them all as winter starts. Similar to the roof overhang, light hits the building during the winter and is blocked during the summer.
  • Geothermal: A geothermal heat exchanger is a great all-purpose system for places that need both heat and AC. More about this one later...
  • Underground: Places that are build in or partially in the earth have less of a temperature change to deal with. It's easy to keep the place at 75 degrees when the outside temperature is 65 degrees year-round.
Heating technologies and ideas for cold places:
  • Passive solar: Bring in as much light as possible, and have it hit a dark-colored thermal mass. The thermal mass is generally a floor, but earthships use a wall. See here for other ideas.
  • Water-based heating: Water-based heating systems are generally more efficient than ones that use air. For nudists who like to go barefoot, an in-floor water-based heating system feels wonderful! Warm feet make people feel warm all over.
  • People: Gather a bunch of them in a small place and things will warm up. Parties are suggested.
  • Fuel: Burning oil, natural gas, or propane has a big disadvantage with the rising cost of the fuel. Corn burners were a good idea until corn-based ethanol took off and raised the price of corn. It seems the best thing to burn is wood, but obtaining a large amount of it each year is hard work. Wood pellets are easier to transport, but hemp pellets are more efficient. Industrial hemp is actually a safe and high-yield crop that grows more and faster than wood, making it good fuel if it would gain popularity. If you go with wood, make sure that your burner is a "woodgas" or "gasification" burner. (Cozy Heat's products, for example.) Not only are they much more efficient, but the emissions are much cleaner as well.
  • Fireplaces: People often supplement their heating systems with a fireplace in a common area. Make sure that your fireplace has a cold air return so that it doesn't suck the heat out of the place.
  • Bathroom and kitchen vents: Don't use these unless needed, because they suck the heat out of your place as well.
  • Windows: A big source for heat loss is through windows. Consider using vacuum insulated ones.
  • Insulation: Prevent the cold from creeping in by adding insulation everywhere you can. A good list of insulations with R-values is here. Also, check out the BrightBuilt Barn in Maine that is so well insulated that it doesn't need a furnace. Buy as much insulation as you can afford!
Cooling technologies and ideas for hot places:
  • Passive solar: You may be thinking that the sun makes heat, so how can it be used to cool a place? The answer is a solar chimney, which gets hot inside and forces the air to rise and exit. The air that exits can be replaced with cool air from an...
  • Earth tube: It's a long underground tube that air travels through. Since the ground temperature is cool and constant, the air becomes cool as it travels through the tube.
  • Basement: since basements are in the ground, the air in them gets cool. Allow outside air to enter the basement and travel upwards through the house through grates in the floor.
  • Whole-building fan: The electric version of a solar chimney. It's a fan that sucks the hot air from the top of the house. This run by a solar panel might be cheaper than building the chimney.
  • Windows: Have windows at the top of the building to let heat out, and at the bottom shaded-side of the building to let in cooler air. Or, just open windows on all sides and let the wind through. Plenty of windows will prevent a building from being stuffy and hot. Don't use this if your using one of the solutions above that brings in cooler air.
  • Evaporative cooling: In dry climates, evaporative cooling works very well. It can produce ideal nudist temperatures with far less electricity than AC. The only downside is the extra water usage.
  • Green roof: If your roof is covered in moist dirt and plants, it will stay cool. This works best only if you have a flat roof.
  • Water: Most people choose to cool off in the pool or with a quick cold shower. This is easy at a nudist resort since they are already in their swimwear. If a pool is nearby, don't worry so much about keeping your buildings cool. Passive cooling should be enough, and an occasional dip in the pool will make the hot days more comfortable.
Staying cool is much easier at a nudist resort since our body's natural form of cooling takes over. The ideas above are probably enough for any southern resort. Is a full AC system really needed?

Back to the topic of geothermal heat exchangers. If you don't know what they are, here's a simple explanation: They are a box that use electricity to make one side hot and the other side cold. Refrigerators and AC units use this as well. Refrigerators make the inside cold and the back hot. AC units make cold air inside the building and hot air outside. Geothermal units make either hot air/water or cold air/water for the building, and make the opposite for the ground outside.

These shouldn't be confused with "geothermal energy", as-in the method used to generate power using hot rocks deep underground. Iceland uses this for almost 90% of their electric and heat, and the runoff forms the huge clothing-optional "blue lagoon". It's too bad systems like this don't exist on a small scale, so just ignore this paragraph.

If you need a heating or cooling system for a building, make sure to check out the common form of geothermal. I know someone here in Wisconsin who installed a system in their medium-sized house, and it uses an average of $40 in electric per month though the winter. This is far cheaper than gas, and far easier than burning wood! (They had both previously.) On the hot summer days, they flip the switch and it produces cold air instead.

Heat exchangers always make a little more heat in the process. In winter, this is good since the building needs heat anyway. In summer, they need to get rid of the extra heat. Most have a water hookup that circulates water to the hot water heater, providing free hot water for most of the summer. This assumes that you have a hot water tank.

If you're like my future resort, you probably won't have a tank of hot water. Instead, I'd use the excess heat from the geothermal system to heat the pool. If the venue has a lake that doesn't freeze, it will work with the geothermal system. Instead of using the ground for one side of the heat exchanger, it can use the lake instead, and might heat it up a few degrees depending on how big it is.

For hot water, there are two ways to reduce cost. First is to use less, and second is to produce it only on demand. There is no need to keep a big tank of water hot all night if nobody is using it. Additionally, most hot water tanks have electric heating elements that kick on while the water is in use.

The main way that hot water (and some water in general) is wasted is when people turn on the shower and fiddle with the knobs to get it the right temperature. They also might have to wait for the hot water to travel through all the pipes, and to warm up all those pipes. People shower a lot at nudist resorts, so getting cheap shower knobs and inefficient hot water is a bad move. I already mentioned low-flow showerheads to conserve water in part 3.1 (Water) of this series. The way to reduce waste further is to produce water of a perfect temperature on demand.

For a single shower, use a simple tankless heater. The Marey models are cheap and easy to attach to existing showers. Make sure to calibrate the water pressure so that the shower is close to 106 degrees F when it is full-on. When a person turns the shower on, it'll be instantly perfect! For a multi-shower system, like for guest rooms or a big pool-side shower room, check out this 6-port water mixer with a digital interface. Combine that with an Eemax 12 GPM tankless heater and you should be set. (Or get a 25 GPM model for the whole building.)

For other areas such as sinks, washing machines, etc, get the size that you need. Eemax makes tankless water heaters of all types and sizes. InSinkErator makes several different types as well, mostly sink faucets and some small tanks for kitchen use.

Hot water tanks have been keeping good pace though, and some claim to be more efficient than the tankless ones. It's difficult to tell which might work better for your venue, but make sure to do your research on both. Remember that less water will be wasted with the tankless, and it'll be a better user experience. I'd love to push a button and have instant perfect water showering over me. However, another way to achieve this is to turn down the water heater.

A good roundup of tankless water heaters can be found in this review.

For a good pre-heater to a water tank, or heating pools, make sure to consider passive solar water heaters. In hot climates, they are so easy to make that you could build one yourself. Get a pipe, paint it black, and put it in a black colored box with a window facing the sun. To move the water, get a small water pump and power it with a solar cell. Using a solar cell, it'll only move the water when the sun is shining and when the water is actually getting heated. Here are some other links to get you started: tank, multi-tank, cheap, beer. For winter installations, the box needs to be insulated well in order to get hot. Antifreeze or glycol is used instead of water, and the heat is pulled from it using a heat exchanger or a small pool. A person I know is planning to build a system like this, and will set a pressurized water tank in a small pool of antifreeze or glycol that will be circulated through the solar box outside. I'll have to report back on how this works next winter.

Before I end the section on sustainability, I should bring up the topic of supplemental heating. It's a good idea to have a backup method of heating, just in case the primary fails. It's also a good idea to use it on the coldest winter days to take the stress off the primary. In my opinion, the best and cheapest option is to burn something. I talked about the different fuel types above. I think corn or industrial hemp (if legal in your country) is a good option if grown locally as part of a garden. In fact, a big garden is a good idea for a resort with acreage. People love to garden nude, and nearly free food is always a plus.

On the other hand, wood is sure plentiful around our area which makes it a great backup for heat. I know a person who uses wood for both heat and hot water. What about the summer? They burn it for the hot water, but are looking into using passive solar instead. He actually enjoys the work of cutting the wood. The cost of pumping the hot water is very small, so they probably have the cheapest heating system that I know of for both water and space heating.

Hopefully by now you have plenty of ideas for greening your venue, and cutting costs. Being efficient is a great way to be profitable. Undercut the other nudist resorts, and you'll dominate the niche market. Undercut the textile resorts, and you'll do more than just succeed -- you'll change attitudes of the general public by showing them a better way of life.



Unknown said...

Tats really very nice information, Thanks for sharing with us.
Gold Coast Accommodation

Anonymous said...

One caveat; as demonstrated by the FEMA trailer debacle, some insulation types can emit toxic gases, formaldehyde being an example. Although resort visitors may have minimal exposure, the staff is there lomger, and in any case your ideas are also applicable in general to home construction.

Unknown said...

I felt so much heat coming through one of my windows even in the winter I started looking into a solar air window heater. I found a great one at that seems to get air hotter than anything on the market. 2 units have cut my heating bill by more than 50%! wow!

Anonymous said...

Mother Earth News a few years ago (a little over 30!)had plans for making window passive solar heaters capable of heating a room. Simple to build, cheap. Maybe plans could be found.

Another article was about using a big pile of compost with drinking water safe plastic tubing inside that heated the water from the heat of composting, plus provided compost. I wonder if that water could be used for home heating also, or separate tubing with circulating air.

I've seen a sauna heated by a small woodstove, fueled with scrapwood. It get's as hot, or hotter, than anyone would want.

Copper tubing coiled inside the chimney could use wasted heat to assist a nearby hot tub...