Radiant Heat and Drywall DONE!

 

We are DONE with dry wall and everything is painted!!! It looks almost like a real house inside. I can top that news by saying WE HAVE HEAT!!!

Lets take a moment to celebrate having a functioning heating system in a cold climate in the middle of winter!

The marathon of drywall is done for now. We still have the master wing of the house to do after we move in but we would like to just pretend we are done for awhile. It was a long slow dusty process but it looks amazing. The flat walls are a cool white and the dome surface is a warm cream. All our color will come from materials not paint colors. We have plans for wood, metal and stone throughout the house. We are finally getting to install more lighting fixtures and finalize all the outlets and switches. To watch a five minute video walk through CLICK HERE.

Greatroom floor outlet in the center of the room. We decided that since the room is 32' across it needed an outlet in the center where furniture would be.

Kids bathroom sconces on either side of a mirror that will be back lit.

Back door gets a small night light.

Hallway from back door facing the kitchen. Kids bedrooms on either side.

Soundproof wall dividing the kitchen from the master suite wing.

Some of the cabinets moved into their rough locations in the kitchen.

Kid bedroom with light bar wall sconces.

We still have the curved great room walls to sheath in plywood. They should be fairly quick to complete but we still have a few more projects ahead of that one. That means just two walls are still studs.

The heating system is not very photogenic and in a tight area so CLICK HERE to watch a video showing our system when we first turned things on. Each day we turned on a new heat zone to allow everything to acclimate. We brought the slab from 45 degrees up to 60 to start out. It takes a lot to change the temperature of all the concrete but then it takes very little to keep it steady. All the thermal mass resists temperature change in either direction. This means our electric bill the first month of it running was a whopper! It ran nonstop trying to bring a super cold slab and house up to temp. We haven't gotten a second bill yet but hopefully this one will be small because it will be just what is needed to maintain temperature. The system only occasionally clicks on even if it is super cold out. The take away from this info... NEVER let it get super cold! We will need to adjust how we approach heating in the winter. To save energy bills in winter we typically turn down our heat at night and when we are not home. That approach will not work with this house. It does not change temperature that easily. It is a situation where you should plan on setting it and just leaving it unless you are going to be gone on vacation for more than a few days. It is going to be an adjustment for us. We are so used to constantly changing the house temperature based on a daily schedule.

We designed the system ourselves with a bend of several sources. We decided to do it ourselves because we do not have any heating companies in our area that are familiar with monolithic domes. The calculations they would give us would not be accurate since they would be basing them on a very different construction style. At least that is the information we have gathered by talking to the builders who have been constructing these homes since the 1960's. 

Our first source of information is Monolithic (the dome company that designed the house) and confirmed by talking with the builders that built the dome shell for us. There is an article on Monolithic's website that explains using an electric water heater instead of a boiler/furnace as your heat source. The key point in the article, if you don't want to read the whole thing, is the wattage needed per square foot for a monolithic dome is different than a conventional house. Their experience has led them to recommend 2 watts per square foot for a monolithic dome radiant system. Typical systems in conventionally constructed homes are 10-12 watts per square foot. Our house is 2700 sq ft so we will need 5,400 watts. This falls within what a standard 50 gallon electric domestic water heater can handle. If you would like to read the in depth (but short) article CLICK HERE. 

Our other sources of information were YouTube and google searching articles. There is an amazing amount of information out there if you take the time to research. Everything we found on YouTube (and in articles) was for conventional homes but it is helpful in understanding best practices.

I wrote the beginning of this entry last month. The heating system has now been functioning for over a month and it has no problems keeping the house warm. That said it was a struggle to get everything up to temperature initially since we turned it on in our coldest month. Here are a few tips on how we laid out our system.

• The house is broken down into zones with each tubing run no longer than 200' to make sure the returning water is still warm for better efficacy
• We thought we would need to mix the 120 degree water out of the tank with cooler water before sending it into the floor but that is not the case. 
• We did not put tubing under areas like the refrigerator, wood stove area or the toilets
• We spaced our tubing loops 10"-12" apart; Monolithic suggests farther apart and conventional systems suggest closer so we split the difference
• We tried to stagger our return tubing containing cooler water near tubing that would have the hottest water to avoid uneven heating in the slab
• We put extra insulation under the slab. Double what code requires.
• We are using in floor thermostat sensors. These are installed in extra empty runs of tubing. We kept the tubing as straight as possible and made sure not to place it too close to tubing avoiding areas where it was the beginning of the run and the water would be at its hottest. We measured the length of these tubes before pouring the floor. We purchased a cheap $15 electrical fish tape and cut it up into the lengths we would need to push the sensor and wire down the runs. The metal tape just stays in the tubing with the sensor and if they need to be replaced we can just pull it out and push a new one back down to the end again.
• We made a primary circulation loop that feeds each zone pump and captures the returning cooler water and sends it back to the tank to be reheated. (see video link above to get details)
• We put in shut off valves everywhere we could think of to make future repairs easier
• Clear tubing for the pumps makes it easier to see bubbles and direction of flow when you are purging the new loops of air

This post is actually behind where we are in the build but I don't want to make it too long. I will try to get to another update to catch up to where we are in the build.