When snow covers the landscape outside, you do your best to preserve the heat inside. [Tom] came up with a smart design for a solder fume extractor that includes a heat recovery ventilator. He created a housing which contains input and output sections. A fan is used to bring in outside air, passing it through a heat exchanger made of alternating panels of coroplast. (See diagrams of his setup after the break) This is really a simple design, and could be built in a couple of hours.
A little digging turns up some good information on making a heat exchanger like this one. [Tom] doesn’t mention the indoor temperature, so it’s difficult to calculate the efficiency he’s getting out of it. Apparently they can attain up to 70% heat transfer, depending on the size of the heat exchanger.
In the video, [Tom] mentions some obvious improvements that could be made, including more efficient fans, and a better housing that allows the core to be removed for cleaning. Still, this is a simple setup that provides a good proof of concept. Perhaps we’ll get to see a more permanent installation from [Tom] in the future.
Continue reading “Solder Fume Extractor With Heat Recovery”
When brewing your own beer, temperature control is important. If the temperature isn’t regulated correctly, the yeast will be killed when it’s added to the wort. It’s best to cool the wort from boiling down to about 25 C quickly before adding yeast.
To do this, [Kalle] came up with a wireless temperature controller for his home brewing setup. The device uses a heat exchanger to cool the wort. An ATmega88 connected to a H-bridge controls a valve that regulates flow through the heat exchanger. It reads the current temperature from a LM35 temperature sensor and actuates the valve to bring the wort to a set point.
A neat addition to the build is a wireless radio. The nRF24L01 module provides a wireless link to a computer. There’s an Android application which communicates with the computer, providing monitoring of the temperatures and control over the set point from anywhere [Kalle] can get an internet connection.
This completely DIY casting furnace turned out just great thanks to all the work [Biolit11] put into it along the way. He wanted to replace his older furnace with one that was more efficient, and to that end he built a heat exchanger into the design. This way the exhaust will preheat the intake air.
The furnace itself started with the shell of an old electric water heater. Excluding the design process, the majority of the build involved mold making. For circular parts he’s using quick tube, the paperboard forms used for pouring concrete footings. For more intricate parts he shaped polystyrene. They are layered in place and high-temperature cement is poured to form the permanent parts. After it hardens the polystyrene can be removed in chunks.
The heat exchanger is the part to the left. It includes several wide, flat pipes made of cement for removing the exhaust. Around those pipes a snaking metal chase carries the intake air which picks up the heat as it passes over the exhaust pipes.
For his first run with the new furnace he melted down a bunch of scrap aluminum and poured ingots.
Here we see [Christopher Suprock] hanging out in his basement laundry area in order to show off his intelligent heat exchanger. The reason for the device is simple, when you use your clothes dryer , hot water heater, other other utilities that generate heat, energy is often wasted in the form of hot exhaust gases. Why not get the most for you clothes drying dollar by sourcing that hot air to warm your house.
The block you see on top of the dryer is a heat exchanger. The exhaust from the dryer passes through a radiator assembly before being vented outside the house. Some control hardware monitors the temperature of the input side and switches on the fan when it detects a higher temperature than the ambient air. Air then flows through the radiator, picking up heat energy from the exhaust gas. See [Christopher’s] explaination, and some thermal readings while the dryer is running, in the video after the break.
This makes us wonder, if the heat exchanger drops the exhaust gas fifty degrees before being vented, will this cause any issues with condensation?
Continue reading “Reclaiming waste heat from appliances”